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The Software-RAID HOWTO

The Software-RAID HOWTO

Jakob ¨ªstergaard ( jakob_at_unthought.net) ¹ø¿ª: Çѽ¼ö, netkevin_AT_hanmail.net

v0.90.8, 2002-08-05 ÃÖÁ¾¹ø¿ªÀÏ: 2004-12-31 ¹Ì¿Ï¼º - °è¼Ó ¹ø¿ªÁßÀÔ´Ï´Ù.
º» ¹®¼­´Â ¸®´ª½º¿¡¼­ Software RAID¸¦ »ç¿ëÇÏ´Â ¹æ¹ý¿¡ ´ëÇØ ±â¼úÇÕ´Ï´Ù. ÀÌ ¹®¼­´Â Ingo Molnar ¹× ´Ù¸¥ ¿©·¯ »ç¶÷ÀÌ ¸¸µç 0.90¹öÀüÀÇ Software RAID¸¦ ´ë»óÀ¸·Î ¸¸µé¾î Á³½À´Ï´Ù. RAID´Â Ä¿³Î 2.4 ÀÌ»óÀÇ ¹öÀü¿¡¼­ ±âº»À¸·Î »ç¿ëÇÒ ¼ö ÀÖÀ¸¸ç ¸î¸î ¸®´ª½º ¹èÆ÷º»¿¡¼­´Â 2.2Ä¿³Î°ú ÇÔ²² Á¦°øÇϱ⵵ Çß½À´Ï´Ù. 0.90¹öÀüÀÇ RAID´Â Ä¿³Î ÆÐÄ¡¸¦ ÇÔÀ¸·Î½á 2.2¹öÀü°ú 2.0¹öÀüÀÇ Ä¿³Î¿¡¼­µµ »ç¿ëÇÒ ¼ö ÀÖÀ¸¸ç ÀÌÀü ¹öÀüÀÇ RAIDº¸´Ù ÈξÀ ´õ ¾ÈÁ¤ÀûÀ¸·Î ÀÛµ¿ÇÕ´Ï´Ù.

1. ¼­¹®

º» ¹®¼­´Â ¹öÀü 2.4 ÀÌ»óÀÇ Ä¿³Î¿¡¼­ »ç¿ëµÇ´Â RAID¿¡ ´ëÇØ ¼³¸íÇÕ´Ï´Ù. 2.0¹öÀü°ú 2.2¹öÀü Ä¿³Î¿¡¼­ »ç¿ëµÇ´ø "ÀÌÀü"¹öÀüÀÇ RAID´Â ¾ð±ÞÇÏÁö ¾Ê½À´Ï´Ù.

ÀÌ ¹®¼­ÀÇ ÃֽŠ¹öÀüÀº http://unthought.net/Software-RAID.HOWTO/¿¡¼­ ±¸ÇÒ ¼ö ÀÖ½À´Ï´Ù. Jakob Østergaard °¡ ÀÛ¼ºÇÑ ÀÌ ¹®¼­´Â RAIDÀÇ °³¹ßÀÚÀÎ Ingo Molnar (mingo@chiara.csoma.elte.hu) ¿Í ¸¹Àº »ç¶÷µéÀÌ ÁÖ°í ¹ÞÀº linux-raid ¸ÞÀϸµ ¸®½ºÆ® (linux-raid@vger.kernel.org) ÀÇ ³»¿ëÀ» ¹ÙÅÁÀ¸·Î ÀÛ¼ºµÇ¾ú½À´Ï´Ù.

2.0¹öÀüÀ̳ª 2.2¹öÀüÀÇ Ä¿³Î¿¡¼­ »õ ¹öÀüÀÇ RAID¸¦ »ç¿ëÇÏ·Á¸é ÀÌ °÷ http://people.redhat.com/mingo/¿¡¼­ Ä¿³Î ÆÐÄ¡¸¦ ±¸ÇØ Àû¿ëÇϽʽÿÀ. ±âº» »óÅÂÀÇ 2.2¹öÀü Ä¿³ÎÀº ÀÌ ¹®¼­¿¡¼­ ¼³¸íÇÏ´Â »õ ¹öÀüÀÇ RAID¸¦ Áö¿øÇÏÁö ¾ÊÀ¸¹Ç·Î ²À Ä¿³Î ÆÐÄ¡¸¦ ÇؾßÇÕ´Ï´Ù. 2.0¹öÀü°ú 2.2¹öÀü¿¡¼­ »ç¿ëÇÏ´Â ÀÌÀü ¹öÀüÀÇ RAID´Â ¹ö±×°¡ ÀÖÀ¸¸ç ¸î °¡Áö Áß¿äÇÑ RAID±â´ÉÀÌ ´©¶ôµÇ¾î ÀÖ½À´Ï´Ù.

RAID¿¡ ´ëÇØ Àß ¾Ë°í °è½Å´Ù¸é ¸î¸î ºÎºÐÀº ÀÐÀ» ÇÊ¿ä°¡ ¾øÀ» °Ì´Ï´Ù.

1.1 Ã¥ÀÓÀÇ ÇÑ°è

º» ¹®¼­ÀÇ ³»¿ëÀ¸·Î ÀÎÇØ ÀϾ ¼ö ÀÖ´Â ¾î¶°ÇÑ ÀÏ¿¡ ´ëÇؼ­µµ ÀúÀÚ ¹× ÇØ´ç ¼ÒÇÁÆ®¿þ¾î °³¹ßÀڴ åÀÓÀ» ÁöÁö ¾Ê½À´Ï´Ù. º» ¹®¼­ÀÇ ³»¿ëÀ» ½ÇÇàÇϱâ Àü¿¡ ±ÍÇÏÀÇ µ¥ÀÌÅ͸¦ ¹é¾÷ÇϽʽÿÀ.

1.2 ¿ä±¸»çÇ×

ÀÌ ¹®¼­´Â ¿©·¯ºÐÀÌ RAID ÆÐÄ¡°¡ Àû¿ëµÈ 2.2¹öÀü°ú 2.0¹öÀüÀÇ Ä¿³ÎÀ» »ç¿ëÇϸç 0.90¹öÀü ÀÌ»óÀÇ RAID À¯Æ¿¸®Æ¼¸¦ »ç¿ëÇÏ°í Àְųª 2.4¹öÀüÀÇ Ä¿³ÎÀ» »ç¿ëÇÑ´Ù´Â °¡Á¤ÇÏ¿¡ ÀÛ¼ºµÈ °ÍÀÔ´Ï´Ù. »ç¿ëµÇ´Â ÆÐÄ¡³ª RAID À¯Æ¿¸®Æ¼´Â ÀÌ °÷ http://people.redhat.com/mingo/¿¡¼­ ±¸ÇÒ ¼ö ÀÖ½À´Ï´Ù. Ä¿³Î ÆÐÄ¡¿Í »óÀÀÇÏ´Â ¹öÀüÀÇ RAID À¯Æ¿¸®Æ¼¸¦ »ç¿ëÇÏ¼Å¾ß ÇÑ´Ù´Â °Íµµ Áß¿äÇÕ´Ï´Ù.

2.4¹öÀü Ä¿³ÎÀÇ GNU/Linux(µ¥ºñ¾È) ¹èÆ÷ÆÇÀ» »ç¿ëÇϽŴٸé RAID »ç¿ë¿¡ Å« ¹«¸®´Â ¾øÀ» °ÍÀÔ´Ï´Ù.

2. RAID¸¦ ¾²´Â ÀÌÀ¯

  • µ¥ÀÌÅÍÀÇ ÀÌÁßÈ­(redundancy)¸¦ À§Çؼ­
  • ¼º´É Çâ»óÀ» À§Çؼ­
  • ¿©·¯ °³ÀÇ ¹°¸®ÀûÀÎ µð½ºÅ©¸¦ ÇϳªÀÇ °¡»ó µð½ºÅ© ó·³ ¹­¾î »ç¿ëÇÏ·Á°í

2.1 RAID ±¸ÇöÀÌ °¡´ÉÇÑ Device ¿Í ÆÄÀÏ ½Ã½ºÅÛ

Linux RAID´Â ´ëºÎºÐÀÇ block devices¿¡¼­ ±¸ÇöÀÌ °¡´ÉÇÕ´Ï´Ù. IDE³ª SCSIÀåÄ¡ ¸ðµÎ »ç¿ë °¡´ÉÇÏ¸ç µÑÀÇ È¥¿ë ¶ÇÇÑ °¡´ÉÇÕ´Ï´Ù. Network Block Device (NBD)¸¦ ÅëÇØ RAID¸¦ ±¸ÇöÇÑ °æ¿ìµµ ÀÖ½À´Ï´Ù.

Linux Software RAID ÀåÄ¡ ±× ÀÚü°¡ ÀÌ¹Ì block deviceÀ̱⠶§¹®¿¡, RAIDÀåÄ¡¸¦ ¸ð¾Æ¼­ ¶Ç RAID¸¦ ±¸¼ºÇÏ´Â °Íµµ °¡´ÉÇÕ´Ï´Ù.. ÀÌ°ÍÀÌ RAID-0°ú RAID-1ÀÇ ÀåÁ¡À» ÇÕÄ£ RAID-10 (RAID-0 of multiple RAID-1 devices)ÀÔ´Ï´Ù. ¶Ç RAID-5 À§¿¡ RAID-5 ¸¦ ±¸ÇöÇÑ "matrix" RAID¿Í °°Àº ÈñÇÑÇÑ RAID±¸¼ºµµ °¡´ÉÇÕ´Ï´Ù.

RAID´Â ÆÄÀϽýºÅÛ°ú´Â ¾Æ¹«·± »ó°üÀÌ ¾ø½À´Ï´Ù. ¾î¶°ÇÑ ÆÄÀÏ ½Ã½ºÅÛ(block deviceÀÇ °æ¿ìó·³)À¸·Îµµ RAID¸¦ ±¸¼ºÇÒ ¼ö°¡ ÀÖ½À´Ï´Ù.

2.2 ¼º´É

RAID´Â ¼º´É Çâ»óÀ» ¸ñÀûÀ¸·Î »ç¿ëµÇ´Â °æ¿ì°¡ ¸¹Áö¸¸ RAIDÀÇ °¢ ·¹º§º° Ư¡À» È®½ÇÈ÷ ÀÌÇØÇÏÁö ¾Ê°í »ç¿ëÇϸé Å« È¿°ú¸¦ ¾òÁö ¸øÇÒ ¼öµµ ÀÖ½À´Ï´Ù.

RAIDÀÇ ·¹º§ÀÇ ¼³¸í¿¡ °¢ ·¹º§ÀÇ ¼º´É»ó Ư¡ÀÌ Àß ³ªÅ¸³ª ÀÖ½À´Ï´Ù.

2.3 ¿ë¾îÀÇ Á¤ÀÇ

"RAID"´Â "Linux Software RAID"¸¦ ¶æÇÕ´Ï´Ù. ÀÌ ¹®¼­´Â Hardware RAID¿¡ ´ëÇØ ¾ð±ÞÇÏÁö ¾Ê½À´Ï´Ù. ¿î¿µÃ¼Á¦ Ä¿³Î¼Ó¿¡¼­ÀÇ Software RAID ±â´É¿¡ ´ëÇØ ¾ð±ÞÇÏÁöµµ ¾Ê½À´Ï´Ù.

RAIDÀÇ ±¸¼ºÀ» ³ªÅ¸³¾ ¶§´Â ¹°¸®Àû µð½ºÅ©ÀÇ °¹¼ö¿Í µð½ºÅ©ÀÇ Å©±â¸¦ ¸í½ÃÇÏ´Â °ÍÀÌ ¾Ë¾Æº¸±â ÆíÇÕ´Ï´Ù. NÀº »ç¿ëµÇ´Â µð½ºÅ©ÀÇ °¹¼ö¸¦ ³ªÅ¸³»¸ç(spare-disk´Â Á¦¿Ü) S´Â º°µµÀÇ ¼³¸íÀÌ ¾ø´Â ÇÑ RAID±¸¼º¿¡ »ç¿ëµÇ´Â °¡Àå ÀÛÀº µð½ºÅ©ÀÇ Å©±â¸¦ ³ªÅ¸³»°Ô µË´Ï´Ù. P´Â RAID arrayÀÇ µð½ºÅ© ÇϳªÀÇ ¼º´ÉÀ» MB/s ´ÜÀ§·Î Ç¥½ÃÇÑ °ÍÀÔ´Ï´Ù. ÀÌ ¶§ RAID array ÀÇ ¸ðµç µð½ºÅ©ÀÇ ¼Óµµ´Â µ¿ÀÏÇÏ´Ù°í °¡Á¤ÇÕ´Ï´Ù.

"device"¿Í "disk"´Â °°Àº Àǹ̷Π»ç¿ëµÇ¾ú½À´Ï´Ù."device"¶ó ÇÔÀº RAID¸¦ ±¸¼ºÇÏ´Â µð½ºÅ©ÀÇ ÆÄƼ¼ÇÀ» ³ªÅ¸³À´Ï´Ù. µ¿ÀÏ µð½ºÅ©»óÀÇ ÆÄƼ¼Çµé¸¸À¸·Î ±¸¼ºµÈ RAID´Â Àǹ̰¡ ¾øÀ¸¹Ç·Î "devices"¿Í "disks"´Â ´Ù¸¥ µð½ºÅ©»óÀÇ ÆÄƼ¼ÇÀ¸·Î »ý°¢ÇÏ½Ã¸é µÇ°Ú½À´Ï´Ù.

2.4 RAIDÀÇ Á¾·ù

¸®´ª½º¿¡¼­ »ç¿ëÇÒ ¼ö ÀÖ´Â RAIDÀÇ Á¾·ù¿¡ ´ëÇØ °£·«È÷ ¼³¸íÇÕ´Ï´Ù. ´ëºÎºÐ RAID¿¡ ´ëÇÑ ±âº»ÀûÀÎ ³»¿ëÀÌÁö¸¸ Á» ´õ Ãß°¡ÇÑ ³»¿ëµµ ÀÖ½À´Ï´Ù.RAID¿¡ ´ëÇÑ ±â¹Ý Áö½ÄÀÌ ÀÖÀ¸½Ã´Ù¸é ÀÌ ºÎºÐÀº ÀÐÁö ¾ÊÀ¸¼Åµµ ¹«¹æÇÕ´Ï´Ù.

RAID¿¡¼­´Â ´ÙÀ½ ·¹º§µéÀ» »ç¿ëÇÒ ¼ö ÀÖ½À´Ï´Ù.

  • Linear mode
    • 2°³ ÀÌ»óÀÇ µð½ºÅ©¸¦ Çϳª·Î ¸¸µé¾î »ç¿ëÇÏ´Â ¹æ¹ýÀÔ´Ï´Ù. ù¹ø° µð½ºÅ©ÀÇ °ø°£ÀÌ ¸ðµÎ Â÷°Ô µÇ¸é µÎ¹ø° µð½ºÅ©·Î À̾ µ¥ÀÌÅ͸¦ ÀúÀåÇÏ´Â °ÍÀÔ´Ï´Ù. ±¸¼º µð½ºÅ©ÀÇ Å©±â°¡ ¸ðµÎ ¶È°°À» ÇÊ¿ä´Â ¾ø½À´Ï´Ù.
    • µ¥ÀÌÅ͸¦ ÀÌÁßÈ­(redundancy)ÇÏ´Â ±â´ÉÀº ¾ø½À´Ï´Ù. ±×·¸±â ¶§¹®¿¡ µð½ºÅ© Çϳª¸¸ °íÀ峪µµ µ¥ÀÌÅ͸¦ ¸ðµÎ ÀÒÀ» ¼ö ÀÖ½À´Ï´Ù. ¿îÀÌ ÁÁÀ¸¸é ¹®Á¦°¡ ¹ß»ýÇÏÁö ¾ÊÀº µð½ºÅ©¿¡¼­ µ¥ÀÌÅÍÀÇ ÀϺθ¦ º¹±¸ÇÒ ¼öµµ ÀÖ½À´Ï´Ù.
    • Àбâ/¾²±â ¼º´ÉÀÌ Çâ»óµÇÁö´Â ¾ÊÁö¸¸ ¿©·¯ »ç¿ëÀÚ°¡ ¿ì¿¬ÇÏ°Ôµµ ´Ù¸¥ µð½ºÅ©¸¦ »ç¿ëÇÏ°Ô µÇ¸é ¼º´É»ó À̵æÀ» º¼ ¼öµµ ÀÖ½À´Ï´Ù..
  • RAID-0
    • ¼ÒÀ§ "stripe"·Î ºÒ¸®´Â ¹æ½ÄÀÔ´Ï´Ù. ¸ðµç devices´Â °°Àº Å©±âÀ̾î¾ß ÇÕ´Ï´Ù.(ÇÏÁö¸¸ ²À °°Áö ¾Ê¾Æµµ »ç¿ëÇÒ ¼ö ÀÖ±ä ÇÕ´Ï´Ù) ¾²±â/Àб⠵¿ÀÛÀº °¢ µð½ºÅ©µé·Î ºÐÇÒµÇ¾î ½ÇÇàµË´Ï´Ù. Áï ¾²±â µ¿ÀÛÀ» ÇÒ ¶§, 0¹ø µð½ºÅ©¿¡ 4 kB, 1¹ø µð½ºÅ©¿¡ 4 kB, 2¹ø µð½ºÅ©¿¡ 4 kB, ±×¸®°í ´Ù½Ã 0¹ø µð½ºÅ©¿¡ 4 kB ±â·ÏÇÏ´Â ½ÄÀ¸·Î µ¿ÀÛÇÕ´Ï´Ù. RAID¸¦ ±¸¼ºÇÏ´Â µð½ºÅ© Áß Çϳª¸¸ ³ª¸ÓÁö °Íµé º¸´Ù Å©´Ù¸é ±× µð½ºÅ©ÀÇ °úÀ× ºÎºÐ¿¡¸¸ ±â·ÏÇÏ°Ô µÇ°í °á°úÀûÀ¸·Î ¼º´É ÀúÇϸ¦ °¡Á®¿É´Ï´Ù.
    • linear¹æ½Äó·³ RAID-0µµ µ¥ÀÌÅÍÀÇ ÀÌÁßÈ­(redundancy)±â´ÉÀÌ ¾ø½À´Ï´Ù. linear¹æ½Ä°ú ´Þ¸® RAID-0Àº ±¸¼ºÇÏ´Â µð½ºÅ© Áß Çϳª¶óµµ °íÀåÀÌ ³ª¼­ µ¥ÀÌÅ͸¦ ÀÒ°Ô µÇ¸é µ¥ÀÌÅ͸¦ Çϳªµµ º¹±¸ÇÒ ¼ö°¡ ¾ø½À´Ï´Ù. RAID-0¿¡¼­ µð½ºÅ©¸¦ Çϳª Á¦°ÅÇÏ°Ô µÇ¸é ¸ðµç µ¥ÀÌÅÍ¿¡ ±¸¸ÛÀÌ »ý±â´Â ¼ÀÀ̹ǷΠe2fsck¿Í °°Àº º¹±¸ ÇÁ·Î±×·¥À¸·Îµµ º¹±¸¸¦ ÇÒ ¼ö ¾ø°Ô µË´Ï´Ù.
    • Àбâ/¾²±â µ¿ÀÛÀÌ °¢°¢ÀÇ µð½ºÅ©¿¡¼­ º´·ÄÀûÀ¸·Î ½ÇÇàµÇ¹Ç·Î ¼º´É Çâ»óÀÌ ÀÖ½À´Ï´Ù. RAID-0À» »ç¿ëÇÏ´Â ÁÖµÈ ÀÌÀ¯°¡ ¹Ù·Î ÀÌ ¼º´É Çâ»ó ¶§¹®ÀÔ´Ï´Ù. °¢ µð½ºÅ©ÀÇ ´ë¿ªÆøÀÌ º¸ÀåµÇ¸é N*P MB/sec ¿¡ °¡±î¿î Àü¼ÛÀ²À» ±â´ëÇÒ ¼ö ÀÖ½À´Ï´Ù..
  • RAID-1
    • RAID-1Àº µ¥ÀÌÅÍ ÀÌÁßÈ­(redundancy)±â´ÉÀÌ ÀÖ½À´Ï´Ù. µÎ °³ ÀÌ»óÀÇ µð½ºÅ©¿Í 0°³ ÀÌ»óÀÇ ¿¹ºñ µð½ºÅ©°¡ ÇÊ¿äÇÕ´Ï´Ù. ÀÌ ¹æ½ÄÀº ÇÑ µð½ºÅ©ÀÇ ³»¿ëÀ» ±×´ë·Î ´Ù¸¥ µð½ºÅ©(µé)¿¡ º¹Á¦(mirroring)ÇÕ´Ï´Ù. ¹°·Ð °¢ µð½ºÅ©µéÀÇ Å©±â´Â µ¿ÀÏÇØ¾ß Çϸç, ¸¸ÀÏ ¼­·Î ´Ù¸¥ Å©±âÀÇ µð½ºÅ©µéÀÌ »ç¿ëµÈ´Ù¸é Å©±â°¡ ÀÛÀº ÂÊÀÇ ¿ë·®À» µû¸£°Ô µË´Ï´Ù.
    • RAID-1¸¦ ±¸¼ºÇÏ´Â µð½ºÅ© Áß Çϳª¸¸ »ì¾Æ³²¾Æµµ(N-1) µ¥ÀÌÅÍ´Â °í½º¶õÈ÷ º¸ÀüµË´Ï´Ù. ¿¹ºñ µð½ºÅ©°¡ ÀÖ´Ù¸é ½Ã½ºÅÛÀÌ Àå¾Ö »óÅ¿¡¼­ º¹±¸µÈ ÈÄ µð½ºÅ©ÀÇ ¿À·ù¸¦ °¨ÁöÇÏ´Â Áï½Ã ¿¹ºñ µð½ºÅ©·ÎÀÇ µ¥ÀÌÅÍ ÀÌÀüÀÌ ½ÃÇàµË´Ï´Ù.
    • µ¥ÀÌÅÍ º¹Á¦¸¦ ÇؾߵDZ⠶§¹®¿¡ ¾²±â(±â·Ï) ¼º´ÉÀº ´ëü·Î ¶³¾îÁý´Ï´Ù.(RAID°¡ ¾Æ´Ñ ÀϹÝÀûÀÎ µð½ºÅ©»ç¿ë°ú ´ëºñÇßÀ» ¶§) ±Ô¸ð°¡ Å« RAID-1ÀÇ °æ¿ì PCI ¹ö½º ´ë¿ªÆøÀÌ µð½ºÅ©°¡ µ¥ÀÌÅÍ º¹Á¦·Î ÀÎÇØ ½É°¢ÇÏ°Ô ÁÙ¾îµé°Ô µÇ¾î ¹®Á¦°¡ µÉ ¼ö ÀÖ½À´Ï´Ù. »ç½Ç ÀÌ Á¡ ¶§¹®¿¡ ¼ÒÇÁÆ®¿þ¾î ¹æ½ÄÀÇ RAID°¡ ¾Æ´Ñ Çϵå¿þ¾î ¹æ½ÄÀÇ RAID¸¦ ¼±ÅÃÇÏ°Ô µÇ´Â °ÍÀÔ´Ï´Ù. Çϵå¿þ¾î RAID¿¡¼­´Â RAID ÄÜÆ®·Ñ·¯°¡ µ¥ÀÌÅÍ º¹Á¦¸¦ Àü´ãÇÏ°Ô µÇ¹Ç·Î PCI ¹ö½ºÀÇ ´ë¿ªÆøÀ» Â÷ÁöÇÏÁö ¾Ê½À´Ï´Ù. RAID´Â ÀÐÀ¸·Á´Â µ¥ÀÌÅÍ¿¡ Çìµå°¡ °¡Àå °¡±îÀÌ À§Ä¡ÇÑ µð½ºÅ©¿¡°Ô Àб⠸í·ÉÀ» ³»¸®´Â read-balancing ¾Ë°í¸®ÁòÀ» ÀÌ¿ëÇØ µ¿ÀÛÇÕ´Ï´Ù. ±× ¶§¹®¿¡ RAID-0Àº ¿©·¯ »ç¿ëÀÚ°¡ µ¿½Ã¿¡ Àбâ ÀÛ¾÷À» ÇÏ´Â °æ¿ì³ª Ž»öÀ» ¸¹ÀÌ ÇÏ´Â °æ¿ì¿¡ ¼º´ÉÀÌ ÁÁ½À´Ï´Ù. Ž»ö ¼öÇàÀº »ó´ëÀûÀ¸·Î ³ë·ÂÀÌ ¸¹ÀÌ µé¾î°¡¹Ç·Î(6 ms ÀÇ Å½»ö½Ã°£Àº 20 MB/secÀÇ ¼Óµµ·Î 123 kB ¸¦ Àд µ¿ÀÛ°ú ¸Â¸Ô½À´Ï´Ù.), µð½ºÅ©ÀÇ Å½»ö ½Ã°£(seek time)ÀÌ ºü¸¥ °ÍÀ» ¼±ÅÃÇÏ´Â °ÍÀÌ ½ÇÁ¦ÀûÀÎ ¼º´É Çâ»óÀ» °¡Á®¿É´Ï´Ù.
  • RAID-4
    • RAID-4´Â ¸¹ÀÌ »ç¿ëµÇÁö´Â ¾Ê½À´Ï´Ù. ÀÌ ¸ðµå´Â ¼¼ °³ ÀÌ»óÀÇ µð½ºÅ©¿¡¼­¸¸ ±¸ÇöÇÒ ¼ö ÀÖ½À´Ï´Ù. ÀÌ ¸ðµå´Â ¹Ì·¯¸µÀ» ÇÏ´Â ´ë½Å Æи®Æ¼ Á¤º¸¸¦ ÇϳªÀÇ µð½ºÅ©¿¡ ±â·ÏÇÏ°í µ¥ÀÌÅÍ´Â RAID-0ó·³ ´Ù¸¥ µð½ºÅ©¿¡ ±â·ÏÇÕ´Ï´Ù. µð½ºÅ© Çϳª´Â Æи®Æ¼ ±â·Ï¿¡¸¸ ¾²À̱⠶§¹®¿¡ Àüü Å©±â´Â (N-1)*S °¡ µÇ°Ú½À´Ï´Ù. ¿©±â¼­ S´Â ±¸¼º µð½ºÅ©Áß °¡Àå ÀÛÀº °ÍÀÇ Å©±âÀÔ´Ï´Ù. RAID-1ÀÇ °æ¿ìó·³ °¢ µð½ºÅ©ÀÇ Å©±â´Â µ¿ÀÏÇØ¾ß ÇÏ¸ç °°Áö ¾ÊÀº Å©±â¶ó¸é À§ÀÇ °ø½Ä¿¡ µû¶ó °¡Àå ÀÛÀº Å©±âÀÇ µð½ºÅ©°¡ Àüü RAIDÀÇ Å©±â¸¦ °áÁ¤ÇÏ°Ô µË´Ï´Ù.
    • ÇÑ °³ÀÇ µð½ºÅ© Àå¾Ö°¡ ¹ß»ýÇϸé Æи®Æ¼ Á¤º¸¸¦ ÀÌ¿ëÇؼ­ µ¥ÀÌÅ͸¦ º¹±¸ÇÕ´Ï´Ù. ÇÏÁö¸¸ µð½ºÅ© µÎ °³¿¡ Àå¾Ö°¡ ¹ß»ýÇÏ°Ô µÇ¸é µ¥ÀÌÅÍ´Â ¼Ò½ÇµË´Ï´Ù.
    • ÀÌ ¹æ½ÄÀÌ Àß »ç¿ëµÇÁö ¾Ê´Â ÀÌÀ¯´Â Æи®Æ¼ Á¤º¸°¡ ÇÑ µð½ºÅ©¿¡¸¸ ÀúÀåµÇ±â ¶§¹®ÀÔ´Ï´Ù. ÀÌ Æи®Æ¼ Á¤º¸´Â µ¥ÀÌÅÍ°¡ ±â·ÏµÉ ¶§¸¶´Ù °»½ÅµÇ¾î¾ß Çϱ⠶§¹®¿¡ Æи®Æ¼¸¦ ÀúÀåÇÏ´Â µð½ºÅ©°¡ ´Ù¸¥ µð½ºÅ©º¸´Ù ¿ùµîÈ÷ ºü¸£Áö ¾Ê´Ù¸é º´¸ñÇö»óÀÌ ¹ß»ýÇϱ⠽±½À´Ï´Ù. ÇÏÁö¸¸ ´Ù¼öÀÇ ´À¸° µð½ºÅ©¿Í ¾ÆÁÖ ºü¸¥ µð½ºÅ© Çϳª¸¦ °®°í °è½Å´Ù¸é »ç¿ëÇØ º¼¸¸ÇÑ ¹æ½ÄÀÌ µÇ°Ú½À´Ï´Ù.
  • RAID-5
    • ÀÌ ¹æ½ÄÀÌ¾ß ¸»·Î µ¥ÀÌÅÍÀÇ ÀÌÁßÈ­¸¦ Çϸ鼭 ¿©·¯°³ÀÇ µð½ºÅ©¸¦ Çϳª·Î ¹­´Â °¡Àå ÈǸ¢ÇÑ ¹æ¹ýÀÔ´Ï´Ù. RAID-5´Â 3°³ ÀÌ»óÀÇ µð½ºÅ©¿Í 0°³ ÀÌ»óÀÇ ¿¹ºñ µð½ºÅ©·Î ±¸¼ºµË´Ï´Ù. RAID-5ÀÇ Å©±â´Â RAID-4ó·³ (N-1)*S ÀÌ µË´Ï´Ù. µÑÀÇ Áß¿äÇÑ Â÷ÀÌ´Â Æи®Æ¼ Á¤º¸°¡ ¿©·¯µð½ºÅ©¿¡ °ñ°í·ç ºÐ»êµÇ¾î ÀúÀåµÈ´Ù´Â Á¡ÀÔ´Ï´Ù. ±×·¡¼­ RAID-4¿¡¼­ ó·³ Æи®Æ¼ Á¤º¸°¡ ¸ô¸®´Â µð½ºÅ©¿¡¼­ ÀϾ´Â º´¸ñÇö»óÀº ¾ø½À´Ï´Ù.
    • ÇÑ µð½ºÅ©¿¡ Àå¾Ö°¡ ¹ß»ýÇصµ Æи®Æ¼ Á¤º¸°¡ ±â·ÏµÇ±â ¶§¹®¿¡ ¸ðµç µ¥ÀÌÅ͸¦ »ì¸± ¼ö°¡ ÀÖ½À´Ï´Ù. ¿¹ºñ µð½ºÅ©°¡ ÀÖ´Ù¸é µð½ºÅ© Àå¾Ö ¹ß»ý Áï½Ã RAID º¹±¸°¡ ½Ç½ÃµË´Ï´Ù. ÇÏÁö¸¸ µ¿½Ã¿¡ µÎ °³ÀÇ µð½ºÅ©¿¡ Àå¾Ö°¡ ¹ß»ýÇÏ¸é ¸ðµç µ¥ÀÌÅÍ´Â ¼Ò½ÇµË´Ï´Ù. RAID-5´Â ÇϳªÀÇ µð½ºÅ© Àå¾Ö¸¸ ó¸®ÇÒ ¼ö ÀÖÀ¸¸ç 2°³ ÀÌ»óÀÇ µð½ºÅ© Àå¾Ö´Â º¹±¸ÇÒ ¼ö ¾ø½À´Ï´Ù.
    • Àбâ/¾²±â ¼º´ÉÀÌ ¸ðµÎ Çâ»óµË´Ï´Ù. ÇÏÁö¸¸ ±× Çâ»ó Á¤µµ´Â ¿¹ÃøÀÌ ½±Áö ¾Ê½À´Ï´Ù. Àб⠼º´ÉÀº RAID-0°ú ºñ½ÁÇÏ¸ç ¾²±â(±â·Ï) ¼º´ÉÀº ´Ù¼Ò ¶³¾îÁö°Å³ª(Á¤È®ÇÑ Æи®Æ¼ Á¤º¸ °è»êÀ» À§ÇØ ±â·Ï¿¡ ¾Õ¼­ read-inÀ» ÇØ¾ß µÇ±â ¶§¹®) RAID-1ÀÇ ¾²±â(±â·Ï)¿Í ºñ½ÁÇÑ Á¤µµÀÔ´Ï´Ù. ¾²±â(±â·Ï) ¼º´ÉÀº ½Ã½ºÅÛÀÇ ¸Þ¸ð¸®¾ç°ú RAIDÀÇ »ç¿ë ÆÐÅÏ¿¡ µû¶ó Â÷ÀÌ°¡ ³³´Ï´Ù. RAID-5ÀÇ ±¸¼º µð½ºÅ© °¹¼ö°¡ ´Ã¾î³¯ ¼ö·Ï ¾²±â(±â·Ï)¿¡ ´õ¿í ´õ ¸¹Àº ½Ã°£°ú ºÎÇÏ°¡ °É¸³´Ï´Ù.

¿¹ºñ µð½ºÅ©

¿¹ºñ µð½ºÅ©¶õ RAID °¡ Àå¾Ö »óÅ¿¡ ºüÁö¸é º¹±¸¿¡ »ç¿ëµÇ´Â µð½ºÅ©¸¦ ¸»ÇÕ´Ï´Ù. µð½ºÅ© Àå¾Ö°¡ °¨ÁöµÇ¸é ±× µð½ºÅ©´Â bad ·Î Ç¥½ÃµÇ°í ù¹ø° ¿¹ºñ µð½ºÅ©·Î º¹±¸°¡ Áï½Ã ½ÃÀ۵˴ϴÙ.

±×·¯¹Ç·Î ¿¹ºñ µð½ºÅ©´Â ƯÈ÷ RAID-5 ½Ã½ºÅÛÀ» ´õ ¾ÈÀüÇÏ°Ô ÇÕ´Ï´Ù. °áÇÔÀÌ ÀÖ´Â µð½ºÅ©·Î RAID¸¦ ¿î¿µÇÏ´Ù ¹ß»ýÇÒ ¼ö ÀÖ´Â ¹®Á¦¸¦ ¿¹ºñ µð½ºÅ©¸¦ »ç¿ëÇÔÀ¸·Î½á ¸·À» ¼ö ÀÖ½À´Ï´Ù.

±×·¡µµ ¾È½ÉÇÒ ¼ö´Â ¾ø½À´Ï´Ù. ¾Æ¹«¸® RAIDÀÇ µð½ºÅ©°¡ ¾ÈÀüÇÏ´Ù°í Çصµ SCSI ÄÜÆ®·Ñ·¯³ª IDE Ĩ¼ÂÀÇ ¿¡·¯ µî¿¡´Â ¹«¹æºñÀÏ ¼ö ¹Û¿¡ ¾ø½À´Ï´Ù.

¶ÇÇÑ º¹±¸´Â µ¥ÀÌÅÍ ÀÌÁßÈ­¿¡ ÇÊ¿äÇÑ Á¤º¸¸¦ Àå¾Ö°¡ ¹ß»ýÇÏÁö ¾ÊÀº µð½ºÅ©¿¡¼­ °¡Á®¿À±â ¶§¹®¿¡ ¿©·¯ µð½ºÅ©¿¡¼­ ¹èµå ºí·°ÀÌ Á¡Á¡ »ý°Ü³ª¸é ºÒ¿ÏÀüÇÑ µ¥ÀÌÅ͸¦ ÀÌ¿ëÇØ º¹±¸¸¦ ÇÏ´Â ¼ÀÀÌ µÇ¹Ç·Î ¸ÖÂÄÇÑ µð½ºÅ©ÀÇ µ¥ÀÌÅ͵µ ¼Õ»óÀÌ µÇ°í °á±¹Àº Àüü RAID°¡ ¸Á°¡Áö´Â °á°ú°¡ »ý±é´Ï´Ù. ÀÚÁÖ ¹é¾÷À» ÇÑ´Ù¸é ÀÌ °°Àº »óȲÀÌ ¹ß»ýÇÒ °¡´É¼ºÀº ÇöÀúÈ÷ ÁÙ¾îµé °ÍÀÔ´Ï´Ù. RAIDµµ ¹é¾÷Àº ÇؾßÇÑ´Ù´Â °ÍÀ» ÀØÁö ¸¶½Ê½Ã¿À.

2.5 RAID¸¦ ½º¿ÒÀ¸·Î

¼º´ÉÀ» ³ôÀÌ·Á°í ½º¿Ò ¿µ¿ªÀ» RAID Àåºñ¿¡ ÀâÀ» ÇÊ¿ä´Â ¾ø½À´Ï´Ù. fstabÆÄÀÏ¿¡¼­ °¢ ½º¿Ò¿µ¿ª¿¡ µ¿ÀÏÇÑ ¿ì¼±¼øÀ§¸¸ ºÎ¿©Çϸé Ä¿³ÎÀÌ ½º½º·Î ºÐ»êµÈ ½º¿Ò¿µ¿ªÀ» »ç¿ëÇÒ ¼ö ÀÖ½À´Ï´Ù.

¿¹:

/dev/sda2       swap           swap    defaults,pri=1   0 0
/dev/sdb2       swap           swap    defaults,pri=1   0 0
/dev/sdc2       swap           swap    defaults,pri=1   0 0
/dev/sdd2       swap           swap    defaults,pri=1   0 0
/dev/sde2       swap           swap    defaults,pri=1   0 0
/dev/sdf2       swap           swap    defaults,pri=1   0 0
/dev/sdg2       swap           swap    defaults,pri=1   0 0
ÀÌ fstab ÆÄÀÏÀº 7°³ÀÇ SCSI µð½ºÅ©¿¡ ÀÖ´Â ½º¿Ò¿µ¿ªÀ» º´·ÄÀûÀ¸·Î »ç¿ëÇÏ´Â ¿¹¸¦ ³ªÅ¸³»°í ÀÖ½À´Ï´Ù. ÀÌ´Â ¿À·¡ÀüºÎÅÍ Ä¿³ÎÀÌ Á¦°øÇÏ´Â ±â´ÉÀÔ´Ï´Ù.

RAID¸¦ ½º¿Ò ¸ñÀûÀ¸·Î ¾²´Â ´Ù¸¥ ÀÌÀ¯´Â °í°¡¿ë¼ºÀ̱⠶§¹®ÀÔ´Ï´Ù. ½Ã½ºÅÛ ºÎÆ® ¿µ¿ªÀÌ RAID-1¿¡ ÀÖÀ¸¸é º¹±¸°¡ °¡´ÉÇϹǷΠ¹®Á¦°¡ ¾øÁö¸¸ ½º¿Ò ¿µ¿ªÀÌ °áÇÔÀ» ³»Æ÷ÇÏ´Â RAID¿¡ ÀÖ´Ù¸é ÀÌ°ÍÀº ¹®Á¦°¡ µË´Ï´Ù. ½º¿Ò ¿µ¿ªÀ» RAID-1¿¡ ÀâÀ¸¸é ÀÌ ¹®Á¦¸¦ ÇØ°áÇÒ ¼ö°¡ ÀÖ´Â °ÍÀÔ´Ï´Ù.

RAID ÀåÄ¡¿¡ ÀÖ´Â ½º¿Ò ¿µ¿ªÀÇ ¾ÈÁ¤¼º¿¡ ´ëÇؼ­´Â ÀÇ°ßÀÌ ºÐºÐÇϸç ÀÌ´Â ½º¿ÒÀº Ä¿³Î°ú °ü·ÃµÈ ³»¿ëÀÌ ¸¹±â ¶§¹®ÀÔ´Ï´Ù. Á¦ »ý°¢¿¡´Â RAID¿¡ ½º¿ÒÀ» »ç¿ëÇÏ´Â °ÍÀº ¹«Ã´ ¾ÈÁ¤ÀûÀÎ °Í °°½À´Ï´Ù.

½º¿Ò ÆÄƼ¼ÇÀ¸·Î RAID¸¦ ¸¸µé ¼öµµ ÀÖ°í(RAIDÀÇ °¢ µð½ºÅ© ÆÄƼ¼Ç ŸÀÔÀ» swapÀ¸·Î ÇÏ°í RAID¸¦ »ý¼ºÇÒ ¼öµµ ÀÖ´Ù´Â ¶æ:¿ªÁÖ) RAID¸¦ ½º¿Ò ÆÄƼ¼ÇÀ¸·Î ¾µ ¼öµµ ÀÖ½À´Ï´Ù. ¾Õ¿¡¼­µµ ¸»¾¸µå·È´Ù½ÃÇÇ RAID´Â ºí·Ï ÀåÄ¡(block device)ÀÏ »ÓÀÔ´Ï´Ù.

3. Çϵå¿þ¾îÀûÀÎ ¹®Á¦

ÀÌ ´Ü¶ô¿¡¼­´Â software RAID ¿î¿µ½Ã ÁÖÀÇÇØ¾ß ÇÒ »çÇ×À» ¼³¸íÇÕ´Ï´Ù.

Á» ´õ ³ªÀº ¼º´ÉÀ» ¾òÀ¸·Á¸é µð½ºÅ©¸¦ ¿¬°áÇÏ´Â ¹ö½º°¡ ÃæºÐÇÑ ´ë¿ªÆøÀ» °¡Áö°í ÀÖ¾î¾ß ÇÕ´Ï´Ù. µð½ºÅ©´ç Àü¼ÛÀ²ÀÌ 20 MB/s ÀÌ°í ¹ö½ºÀÇ ´ë¿ªÆøÀÌ 160 MB/s ¶ó°í ÇÒ ¶§ ÇϳªÀÇ Ultra Wide ½ºÄ«½Ã ÄÜÆ®·Ñ·¯¿¡ 14°³ÀÇ µð½ºÅ©¸¦ ¿¬°áÇÏ´Â ÀÏÀº ¾ø¾î¾ß ÇÏ°Ú½À´Ï´Ù. ±×¸®°í ÇϳªÀÇ IDE ÄÜÆ®·Ñ·¯´ç ÇϳªÀÇ µð½ºÅ©¸¸ ¿¬°áÇÏ¼Å¾ß ÇÕ´Ï´Ù. ¸¶½ºÅÍ/½½·¹ÀÌºê µð½ºÅ©¸¦ ¸ðµÎ RAID·Î ¿¬°áÇØ »ç¿ëÇÏ´Â °ÍÀº ¼º´ÉÀÌ ¾öû³ª°Ô ÀúÇ쵃 ¿ì·Á°¡ ÀÖ½À´Ï´Ù. IDE´Â ¹ö½º´ç µÎ °³ÀÌ»óÀÇ µð½ºÅ©°¡ ¾×¼¼½º µÉ ¶§¿¡´Â ¾öû³ª°Ô ´À·ÁÁý´Ï´Ù. ÇÏÁö¸¸ ¿äÁòÀÇ ½ÅÇü ¸ÞÀκ¸µåµéÀº IDE¹ö½º°¡ µÎ °³¾¿ ÀÖ´Â °Íµµ ÀÖÀ¸¹Ç·Î Ãß°¡ ºñ¿ë¾øÀÌ Á» ´õ ³ªÀº ¼º´ÉÀÇ RAID¸¦ ¿î¿µÇÒ ¼ö ÀÖ½À´Ï´Ù. ¹°·Ð IDE ÄÜÆ®·Ñ·¯ °¡°Ýµµ Àú·ÅÇϹǷΠ¿©·¯°³ÀÇ IDE ÄÜÆ®·Ñ·¯¸¦ ´Þ¾Æ¼­ 6-8°³ Á¤µµÀÇ µð½ºÅ©·Î µÈ RAID¸¦ ¿î¿µÇÏ´Â ¹æ¹ýµµ ³ª»ÚÁö´Â ¾ÊÀ» °ÍÀÔ´Ï´Ù.

3.1 IDE ¼³Á¤

IDE µð½ºÅ©·Î ±¸¼ºµÈ RAID¸¦ ¿î¿µÇÏ´Â ¹æ¹ýµµ ÀÖÀ¸¸ç ¼º´Éµµ ÁÁ½À´Ï´Ù. ÀϹÝÀûÀ¸·Î IDE µð½ºÅ©¿Í ÄÜÆ®·Ñ·¯ÀÇ °¡°ÝÀÌ Àú·ÅÇϹǷΠIDE RAID¸¦ °í·ÁÇØ º¸´Â °Íµµ ±¦ÂúÀ» °ÍÀÔ´Ï´Ù.

  • Physical stability: IDE µð½ºÅ©´Â ÀϹÝÀûÀ¸·Î ½ºÄ«½Ã µð½ºÅ©¿¡ ºñÇØ ¼º´É°ú ÁúÀÌ ¶³¾îÁö´Â °ÍÀ¸·Î ¾Ë·ÁÁ® ÀÖ½À´Ï´Ù. ½ºÄ«½Ã µð½ºÅ©´Â º¸Áõ±â°£ÀÌ 3-5³â Àε¥ ºñÇØ IDE µð½ºÅ©´Â ´ëü·Î 1³â Á¤µµÀÇ º¸Áõ±â°£À» ³»°É°í ÀÖ½À´Ï´Ù. ²À ±×·¸´Ù´Â ¾ê±â´Â ¾Æ´ÏÁö¸¸ ¾î¶² Á¦Á¶È¸»çÀÇ Á¦Ç°Àº °íÀåÀÌ Àæ±âµµ ÇÕ´Ï´Ù. °á·ÐÀº ¸ðµç µð½ºÅ©´Â °íÀå °¡´É¼ºÀ» ³»Æ÷ÇϹǷΠ±×¿¡ ´ëÇÑ ´ëºñ¸¦ ÇؾßÇÑ´Ù´Â °ÍÀÔ´Ï´Ù.
  • µ¥ÀÌÅÍ ¹«°á¼º: ¿¹ÀüÀÇ IDE ¹æ½ÄÀº IDE ¹ö½º·Î º¸³»Áö´Â µ¥ÀÌÅÍ¿Í ½ÇÁ¦·Î µð½ºÅ©¿¡ ±â·ÏµÇ´Â ³»¿ëÀÌ µ¿ÀÏÇÑÁö ¾Ë ¼ö ÀÖ´Â ¹æ¹ýÀÌ ¾ø¾ú½À´Ï´Ù. ÀÌ´Â Æи®Æ¼³ª üũ¼¶ µîÀÇ ±â¼úÀÌ ¾ø¾ú±â ¶§¹®ÀÔ´Ï´Ù. ÇÏÁö¸¸ ¿äÁòÀÇ Ultra-DMA´Â IDE µð½ºÅ©µµ üũ¼¶ °è»êÀ» Çϱ⶧¹®¿¡ µ¥ÀÌÅÍ°¡ º¯Á¶µÉ °¡´É¼ºÀº °ÅÀÇ ¾ø½À´Ï´Ù. Âü°í·Î The PCI ¹ö½º ÀÚü´Â Æи®Æ¼³ª üũ¼¶ Á¤º¸¸¦ ¾²Áö ¾Ê½À´Ï´Ù.
  • ¼º´É:IDEÀÇ ¼º´É¿¡ ´ëÇؼ­ Á¶±Ý¸¸ ¾ê±âÇØ º¸µµ·Ï ÇÏ°Ú½À´Ï´Ù.
    • ÀÌ ±ÛÀÌ ÀÛ¼ºµÈ ½ÃÁ¡¿¡¼­ IDEµð½ºÅ©´Â ½ºÄ«½Ã µð½ºÅ©Ã³·³ 10,000 ¶Ç´Â 15,000 rpmÀÇ ¼Óµµ¸¦ °¡ÁöÁø ¾ÊÁö¸¸ ±×·¡µµ ºü¸¥ Æí¿¡ ¼ÓÇÕ´Ï´Ù.
    • IDE´Â ½ºÄ«½Ã¿¡ ºñÇØ CPU ¼Ò¸ðÀ²ÀÌ ´õ Å®´Ï´Ù.(º° »ó°ü ¾øÀ» ¼öµµ ÀÖ½À´Ï´Ù)
    • ÇϳªÀÇ IDE¹ö½º´ç µð½ºÅ© Çϳª¸¸ »ç¿ëÇϽʽÿÀ. slave µð½ºÅ©±îÁö ´Þ¾Æ¼­ »ç¿ëÇÏ¸é ¼º´ÉÀÌ ¾öû³ª°Ô ÀúÇϵ˴ϴÙ.
  • Àå¾Ö ó¸®: IDE ¿¡¼­´Â ¿¬°áµÈ µð½ºÅ©°¡ °íÀ峪µµ Å« ÁöÀåÀº ¾ø½À´Ï´Ù. RAID °¡ °íÀå³­ µð½ºÅ©¸¦ ÀÎÁöÇÏ°í RAID ·¹º§ 1 ÀÌ»óÀ¸·Î ¿î¿µÇÏ°í ÀÖ´Ù¸é ÀÚµ¿À¸·Î ´ëóÇÒ °ÍÀÔ´Ï´Ù.

ÇϳªÀÇ IDE ¹ö½º´ç ÇϳªÀÇ µð½ºÅ©¸¸ ¿¬°áÇؼ­ »ç¿ëÇØ¾ß ÇÑ´Ù´Â °ÍÀº ¸Å¿ì Áß¿äÇÑ Á¡ÀÔ´Ï´Ù. ±×·¸°Ô ÇÏÁö ¾ÊÀ¸¸é ¼º´É ÀúÇϻӸ¸ ¾Æ´Ï¶ó ¸¸¾à µð½ºÅ©°¡ °íÀ峪¸é IDE ¹ö½º Àüü·Î ¿À·ù°¡ ÆÛÁö°Ô µÇ¸ç ±× ¹ö½º¿¡ ¿¬°áµÈ ¸ðµç µð½ºÅ©¿¡ Àå¾Ö°¡ ¹ß»ýÇÏ°Ô µË´Ï´Ù. Àå¾Ö 󸮰¡ °¡´ÉÇÑ RAID (RAID ·¹º§ 1,4,5)´Â ÇÑ °³ÀÇ µð½ºÅ© Àå¾Ö´Â ó¸®ÇÒ ¼ö ÀÖÁö¸¸, µÎ °³ ÀÌ»óÀÇ µð½ºÅ© Àå¾Ö´Â ó¸®ÇÒ ¼ö°¡ ¾ø±â ¶§¹®¿¡ À§ÇèÇÑ °ÍÀÔ´Ï´Ù. IDE ¹ö½º Çϳª´ç ÇϳªÀÇ µð½ºÅ©, ÀÌ°ÍÀº Á¤¸» Áß¿äÇÑ °ÍÀÔ´Ï´Ù.

¿©·¯ °³ÀÇ IDE ÄÜÆ®·Ñ·¯ ±¸¸Å¿¡ µ·ÀÌ ¸¹ÀÌ µé¾îµµ IDE µð½ºÅ©ÀÇ °¡°ÝÀÌ ½ºÄ«½Ã¿¡ ºñÇØ ÈξÀ Àú·ÅÇϹǷΠIDE µð½ºÅ©¸¦ ¸¹ÀÌ °¡Áö°í ÀÖ´Â °æ¿ì¶ó¸é Á¤¸» ±¦ÂúÀº ¹æ¹ýÀÌ µÉ °ÍÀÔ´Ï´Ù.

±Ô¸ð°¡ Ä¿Áö°Ô µÇ¸é ÄÉÀÌºí¸µµµ ¹®Á¦¸¦ ¾ß±âÇÒ ¼ö ÀÖÀ¸¹Ç·Î IDE ÄÉÀ̺íÀÇ ±æÀÌ°¡ ³Ê¹« ±æ¾îÁöÁö ¾Ê°Ô ÁÖÀÇÇØ¾ß ÇÕ´Ï´Ù.

°Ô´Ù°¡ ÃÖ±ÙÀÇ ¾î¶² µð½ºÅ©´Â ÇÏ·ç´ç »ç¿ë ½Ã°£ Á¦ÇÑÀÌ ÀÖ´Â °Íµµ ÀÖ½À´Ï´Ù. ±×·± µð½ºÅ©µéÀº µ¥½ºÅ©Å¾ ¿ëÀ̱⠶§¹®¿¡ ¹«Á¤Áö·Î ¿î¿µÇÒ ½Ã½ºÅÛ¿¡ »ç¿ëÇÏ´Â °ÍÀº ½É°¢ÇÑ °á°ú¸¦ ÃÊ·¡ÇÒ ¼öµµ ÀÖÀ» °Ì´Ï´Ù.

3.2 ÇÖ½º¿Ò ±â´É

µð½ºÅ©ÀÇ ÇÖ½º¿ÒÀº ÁÖÀÇÇؾßÇÒ Á¡µéÀÌ ¸¹½À´Ï´Ù.

IDE µð½ºÅ©ÀÇ ÇÖ½º¿Ò

IDE µð½ºÅ©´Â ÇÖ½º¿ÒÀÌ ¾ÈµË´Ï´Ù. ¹°·Ð, IDE µå¶óÀ̹ö°¡ ¸ðµâ·Î ÄÄÆÄÀϵǾî ÀÖ´Ù¸é µð½ºÅ©¸¦ ±³Ã¼ÇÏ°í ¸ðµâÀ» ´Ù½Ã ¿Ã¸®´Â ¹æ¹ýÀÌ Àֱ⵵ ÇÒ°Ì´Ï´Ù.(2.2 ¹öÀüÀÇ Ä¿³Î¿¡¼­¸¸ µÇ´ø ±â´ÉÀÔ´Ï´Ù) ÇÏÁö¸¸ IDE ÄÜÆ®·Ñ·¯³ª µð½ºÅ©¸¦ Å¿ì°Ô µÇ´Â ºÒ»ó»ç¸¦ °ÞÀ» ¼öµµ ÀÖ½À´Ï´Ù.

¹®Á¦´Â(Çϵå¿þ¾îÀûÀ¸·Î ¼Õ»óÀ» ÀÔÈ÷´Â Àü±âÀûÀÎ ¹®Á¦´Â Á¦¿Ü) µð½ºÅ©°¡ ±³Ã¼µÈ ÈÄ¿¡ IDE ¹ö½º´Â ´Ù½Ã ÀÐÇôÁ®¾ß(re-scanning) µÈ´Ù´Â °ÍÀÔ´Ï´Ù. »õ ¹öÀüÀÇ Ä¿³ÎÀÌ ÀÌ ±â´ÉÀ» Áö¿øÇϱä ÇÏÁö¸¸(hdparm À¯Æ¿¸®Æ¼¸¦ ÀÌ¿ë), ÆÄƼ¼Ç Á¤º¸¸¦ ´Ù½Ã ÀоîµéÀÌ´Â °Í±îÁö´Â µÇÁö ¾Ê½À´Ï´Ù. ±³Ã¼µÈ µð½ºÅ©°¡ ±³Ã¼ÀüÀÇ µð½ºÅ©¿Í 100% µ¿ÀÏ(ÆÄƼ¼Ç ±¸Á¶µî ¸ðµç °Í)ÇÏ´Ù¸é °¡´ÉÇÒ ¼öµµ ÀÖ°ÚÁö¸¸ ¿©ÀüÈ÷ À§ÇèÀ» °¨¼öÇØ¾ß ÇÒ °ÍÀÔ´Ï´Ù.

SCSI µð½ºÅ©ÀÇ ÇÖ½º¿Ò

º¸ÅëÀÇ SCSI Çϵå¿þ¾îµµ ÇÖ½º¿ÒÀÌ ¾ÈµÇ±ä ¸¶Âù°¡ÁöÀÌÁö¸¸ µÉ ¼öµµ ÀÖ±ä ÇÕ´Ï´Ù. ¹ö½º ¸®½ºÄ³´×À» Áö¿øÇϸé ÇÖ½º¿ÒÀÌ µÇ´Â °Ì´Ï´Ù. ÇÏÁö¸¸ Àü¿øÀÌ µé¾î¿Í ÀÖ´Â »óÅ¿¡¼­ ÀåÄ¡¸¦ Å»/ºÎÂøÇÏ´Â ÇàÀ§´Â ¾ø¾î¾ß ÇÏ°Ú½À´Ï´Ù. ÀÌ ¿ª½Ã ¼º°øÇÒ ¼öµµ ÀÖÁö¸¸ Àåºñ°¡ Å» ¼öµµ ÀÖ´Ù´Â °ÍÀ» ¸í½ÉÇϽʽÿÀ.

SCSI ¿¡¼­´Â µð½ºÅ©°¡ °íÀ峪µµ À̸¦ ´ëóÇÒ ¼ö ÀÖ¾î¾ß ÇÕ´Ï´Ù¸¸ ¸ðµç SCSI ÄÜÆ®·Ñ·¯°¡ ±×·² ¼ö ÀÖ´Â ¾Æ´Õ´Ï´Ù. µð½ºÅ©°¡ °íÀ峪¼­ SCSI ÄÜÆ®·Ñ·¯µµ Á×°í ½Ã½ºÅÛ±îÁö °°ÀÌ Á×´Â ÀÏÀÌ »ý±ä´Ù¸é ÇÖ½º¿ÒÀº µµ¿òÀÌ µÇÁö ¸øÇÕ´Ï´Ù.

SCA(Single Connection Attach)ÀÇ ÇÖ½º¿Ò

SCA´Â ÇÖ½º¿ÒÀÌ µË´Ï´Ù. ½±Áö´Â ¾ÊÁö¸¸ ¾ÈÀüÇÑ ¹æ¹ýÀÔ´Ï´Ù.

´ÙÀ½ ¿¹Á¦Ã³·³ RAID µð½ºÅ©¸¦ ±³Ã¼ÇϽʽÿÀ:

  • µð½ºÅ© »óÅ°¡ ±×³ª¸¶ ¾çÈ£ÇÏ´Ù¸é Àå¾Ö°¡ ÀϾ µð½ºÅ©¿¡¼­ ÆÄƼ¼Ç Å×À̺í Á¤º¸¸¦ ¹é¾÷¹Þ½À´Ï´Ù:
    sfdisk -d /dev/sdb > partitions.sdb
    
  • ´ÙÀ½ ¸í·É¾î·Î RAID ¿¡¼­ µð½ºÅ©¸¦ Á¦°ÅÇÕ´Ï´Ù(RAID ÇÁ·Î±×·¥ »ó¿¡¼­):
    raidhotremove /dev/md0 /dev/sdb1
    
  • ´ÙÀ½ÀÇ ÆÄÀÏ¿¡¼­ ±³Ã¼ÇÒ µð½ºÅ©ÀÇ Host, Channel, ID, Lun Á¤º¸¸¦ ¾Ë¾ÆµÓ´Ï´Ù:
    /proc/scsi/scsi
    
  • SCSI ¹ö½º¿¡¼­ µð½ºÅ©¸¦ Á¦°ÅÇÕ´Ï´Ù(ÆÄÀÏ¿¡¼­ Á¦°ÅÇÑ´Ù´Â ¶æ):
    echo "scsi remove-single-device 0 0 2 0" > /proc/scsi/scsi
    
  • ´ÙÀ½ ÆÄÀÏÀ» ÅëÇÏ¿© Á¦´ë·Î µð½ºÅ©°¡ Á¦°ÅµÇ¾ú´Â°¡¸¦ È®ÀÎÇÕ´Ï´Ù:
    /proc/scsi/scsi
    
  • µð½ºÅ©¸¦ ±³Ã¼ÇÕ´Ï´Ù(½ÇÁ¦ÀûÀÎ µð½ºÅ© ±³Ã¼¸¦ ÀǹÌ, ¹°¸®ÀûÀ¸·Î ±³Ã¼):
  • SCSI ¹ö½º¿¡ µð½ºÅ©¸¦ ÀνĽÃŵ´Ï´Ù:
    echo "scsi add-single-device 0 0 2 0" > /proc/scsi/scsi
    
    (ÀÌ ¸í·ÉÀº µð½ºÅ©ÀÇ È¸ÀüÀ» ½ÃÀÛÇÏ°Ô ÇÕ´Ï´Ù)
  • ¹é¾÷¹Þ¾ÆµÐ ÆÄƼ¼Ç Å×À̺í Á¤º¸·Î »õ µð½ºÅ©¸¦ ÆÄƼ¼Å´×ÇÕ´Ï´Ù:
    sfdisk /dev/sdb < partitions.sdb
    
  • RAID ¿¡ »õ µð½ºÅ©¸¦ Ãß°¡ÇÕ´Ï´Ù:
    raidhotadd /dev/md0 /dev/sdb2
    

À§ÀÇ "scsi remove-single-device" ¸í·É¿¡ Àμö·Î Àü´ÞµÇ´Â ¼ýÀÚµéÀº °¢°¢: Host, Channel, Id, Lun À» ÀǹÌÇÕ´Ï´Ù. ÀÌ °ªµéÀº "/proc/scsi/scsi" ÆÄÀÏ¿¡¼­ È®ÀÎÇÒ ¼ö ÀÖ½À´Ï´Ù.

À§ÀÇ ¿¹Á¦´Â IBM »çÀÇ SCA¹æ½Ä µð½ºÅ©¿Í Adaptec »çÀÇ SCSI ÄÜÆ®·Ñ·¯¿¡¼­ ¼öÇà/Å×½ºÆ®µÈ °ÍÀÔ´Ï´Ù. ÀÌ ¿¹Á¦´ë·Î ½ÇÇàÁß ¹®Á¦°¡ ¹ß»ýÇϰųª °³¼±Á¡À» ãÀ¸¼Ì´Ù¸é linux-raid ¸ÞÀϸµ ¸®½ºÆ®¸¦ ÅëÇØ ¾Ë·ÁÁֽñ⠹ٶø´Ï´Ù.

4. RAID ¼³Á¤

4.1 °øÅë ¼³Á¤ »çÇ×

Áغñ¹°Àº ÀÌ·¸½À´Ï´Ù.

  • 2.4 ¹öÀüÀÇ ÀÌ»óÀÇ Ä¿³Î, ¶Ç´Â ÆÐÄ¡°¡ µÈ 2.0 , 2.2 ¹öÀüÀÇ Ä¿³Î.
  • RAID À¯Æ¿¸®Æ¼.
  • Àγ»½É, ÇÇÀÚ, ¿©·¯ºÐÀÌ ¼±È£ÇÏ´Â Ä«ÆäÀÎ ÇÔÀ¯ À½·á.

ÀÌÁ¦ºÎÅÍ ³ª¿À´Â ³»¿ëÀº ´ëºÎºÐÀÇ ¹èÆ÷ÆÇ¿¡¼­ ¸ðµÎ Ç¥ÁØÀÎ °ÍµéÀÔ´Ï´Ù.

¿©·¯ºÐ ½Ã½ºÅÛÀÇ Ä¿³ÎÀÌ RAID¸¦ Áö¿øÇÏ°í ÀÖ´Ù¸é /proc/mdstat À̶ó´Â ÆÄÀÏÀÌ ÀÖÀ» °Ì´Ï´Ù. ÀÌ ÆÄÀÏÀº RAID¸¦ »ç¿ëÇÏ´Â µ¥ ÀÖ¾î ¿©·¯ºÐÀÇ Ä£±¸¿Íµµ °°Àº Á¸ÀçÀÔ´Ï´Ù. cat /proc/mdstat ¸¦ Çϼż­ ³»¿ëÀ» ÇÑ ¹ø º¸½Ã±â ¹Ù¶ø´Ï´Ù. ±× ÆÄÀÏÀ» ÅëÇØ ¿©·¯ºÐÀÇ RAID µ¿ÀÛ ¿©ºÎ¿Í ¿Ã¹Ù¸£°Ô ¼³Á¤ÀÌ µÇ¾ú´Â°¡ÀÇ ¿©ºÎµîÀ» ¾Ë ¼ö ÀÖ½À´Ï´Ù.

RAID ¿¡ Æ÷ÇÔ½Ãų ÆÄƼ¼ÇÀ» »ý¼ºÇϽʽÿÀ.

ÀÌÁ¦ °¢ RAID ·¹º§ º° ¼³Á¤À» ÇØ º¸°Ú½À´Ï´Ù.

4.2 Linear mode

¼­·Î Å©±â°¡ ´Ù¸¥(°°¾Æµµ µË´Ï´Ù) ÆÄƼ¼ÇÀ» ÇÕÄ¡´Â °æ¿ìÀÔ´Ï´Ù.

/etc/raidtab ÆÄÀÏÀ» ÅëÇØ ¼³Á¤ÇÕ´Ï´Ù. µÎ µð½ºÅ©¸¦ linear ¸ðµå·Î ¼³Á¤ÇÏ´Â ÆÄÀÏÀÇ ³»¿ëÀÔ´Ï´Ù.

raiddev /dev/md0
        raid-level      linear
        nr-raid-disks   2
        chunk-size      32
        persistent-superblock 1
        device          /dev/sdb6
        raid-disk       0
        device          /dev/sdc5
        raid-disk       1
ÇÑ µð½ºÅ©¿¡ Àå¾Ö°¡ »ý±â¸é ±× RAID Àüüµµ °°ÀÌ Á×½À´Ï´Ù. ±×·¡¼­ ¿¹ºñ µð½ºÅ© ¼³Á¤Àº Àǹ̰¡ ¾ø±â ¶§¹®¿¡ »ý·«µÇ¾ú½À´Ï´Ù.

º´·ÄÀûÀ¸·Î »ç¿ëÇÏ´Â °Íµµ ¾Æ´Ñµ¥ ¿Ö chunk-size ¸¦ Ç¥±âÇÏ´ÂÁö ±Ã±ÀÇÏ½Ç °Ì´Ï´Ù. ¸Â½À´Ï´Ù. »çÁ·°ú °°Àº °ÍÀ̱⠶§¹®¿¡ ½Å°æ¾²½Ç ÇÊ¿ä¾ø½À´Ï´Ù.

ÀÌÁ¦ RAID¸¦ »ý¼ºÇÕ´Ï´Ù. ´ÙÀ½ ¸í·ÉÀ» ½ÇÇàÇÕ´Ï´Ù.

  mkraid /dev/md0

ÀÌ ¸í·ÉÀº RAID¸¦ ÃʱâÈ­ÇÏ°í persistent superblockÀ» ±â·ÏÇϸç RAID¸¦ ±âµ¿ÇÏ°Ô µË´Ï´Ù.

/proc/mdstat ÆÄÀÏÀÇ ³»¿ëÀ» È®ÀÎÇØ º¸½Ê½Ã¿À. °¡µ¿ÁßÀ̶ó´Â ¾Ë ¼ö ÀÖÀ» °Ì´Ï´Ù.

ÀÌÁ¦ º¸ÅëÀÇ µð½ºÅ©Ã³·³ ÆÄÀϽýºÅÛÀ» ¸¸µé°í, ¸¶¿îÆ®ÇÏ°í fstab ÆÄÀÏ¿¡ Ãß°¡ÇÏ´Â ÀÛ¾÷À» ÇØÁÖ½Ã¸é µË´Ï´Ù.

4.3 RAID-0

ºñ½ÁÇÑ Å©±âÀÇ µð½ºÅ©°¡ µÎ °³ ÀÌ»ó ÀÖ´Ù°í ÇÒ ¶§ µÎ ¿ë·®À» ÇÕÄ¡¸é¼­ º´·Ä»ç¿ëÀ» ÅëÇØ ¼º´Éµµ Çâ»ó½ÃÅ°°íÀÚ ÇÏ´Â °æ¿ì°¡ µÇ°Ú½À´Ï´Ù.

¿ª½Ã /etc/raidtab ÆÄÀÏÀ» ¼öÁ¤ÇÕ´Ï´Ù.

raiddev /dev/md0
        raid-level      0
        nr-raid-disks   2
        persistent-superblock 1
        chunk-size     4
        device          /dev/sdb6
        raid-disk       0
        device          /dev/sdc5
        raid-disk       1
Linear ¸ðµå¿Í ¸¶Âù°¡Áö·Î RAID-0Àº µ¥ÀÌÅÍ ÀÌÁßÈ­ ±â´ÉÀÌ ¾øÀ¸¹Ç·Î ¿¹ºñ µð½ºÅ©´Â »ç¿ëÇÒ ¼ö ¾ø½À´Ï´Ù.

´ÙÀ½À» ½ÇÇàÇÕ´Ï´Ù.

  mkraid /dev/md0
superblockÀ» ÃʱâÈ­ÇÏ°í RAID¸¦ ±âµ¿ÇÕ´Ï´Ù. /proc/mdstat ÆÄÀÏÀ» ÅëÇØ ÀÛµ¿¿©ºÎ¸¦ È®ÀÎÇÒ ¼ö ÀÖ½À´Ï´Ù.

/dev/md0 À» ÀÌÁ¦ Æ÷¸ËÇÏ°í ¸¶¿îÆ®Çؼ­ »ç¿ëÇÏ¸é µË´Ï´Ù.

4.4 RAID-1

ºñ½ÁÇÑ Å©±âÀÇ µð½ºÅ©°¡ µÎ °³ ÀÖ°í ÇÑ µð½ºÅ©°¡ ´Ù¸¥ µð½ºÅ©¸¦ ¹Ì·¯¸µÇÏ°Ô ÇÏ´Â °æ¿ìÀÔ´Ï´Ù. ¿©ºÐÀÇ µð½ºÅ©¸¦ ¿¹ºñ µð½ºÅ©·Î ÁöÁ¤ÇØ ³õÀ¸¸é RAID¿¡ Àå¾Ö°¡ »ý±â¸é ÀÚµ¿À¸·Î ¿¹ºñ µð½ºÅ©°¡ ±× µð½ºÅ©¸¦ ±³Ã¼Çؼ­ ¹Ì·¯¸µÀ» ÇÏ°Ô µÉ °Ì´Ï´Ù.

RAID-1 ÀÇ /etc/raidtab ÆÄÀÏÀº ÀÌ·¸½À´Ï´Ù.:

raiddev /dev/md0
        raid-level      1
        nr-raid-disks   2
        nr-spare-disks  0
        chunk-size     4
        persistent-superblock 1
        device          /dev/sdb6
        raid-disk       0
        device          /dev/sdc5
        raid-disk       1
¿¹ºñ µð½ºÅ© Ãß°¡´Â µÞºÎºÐ¿¡ ÀÌ·¸°Ô Ãß°¡ÇØ ÁÖ½Ã¸é µË´Ï´Ù.
        device          /dev/sdd5
        spare-disk      0
nr-spare-disks ºÎºÐÀ» Á¤È®È÷ ¼³Á¤ÇØ Áֽô °ÍÀ» ÀØÁö ¸¶½Ê½Ã¿À.

ÀÌÁ¦ RAID¸¦ ±âµ¿ÇÒ Áغñ°¡ µÇ¾ú½À´Ï´Ù. µÎ µð½ºÅ©ÀÇ ³»¿ëÀ» °°°Ô ¸¸µé¾îÁà¾ß ÇÕ´Ï´Ù.

´ÙÀ½ ¸í·ÉÀ» ½ÇÇàÇϽʽÿÀ.

  mkraid /dev/md0
¹Ì·¯¸µÀÇ ÃʱâÈ­¸¦ ½ÃÀÛÇÕ´Ï´Ù.

/proc/mdstat ÆÄÀÏÀ» È®ÀÎÇϽʽÿÀ. raid ÀåÄ¡ÀÇ µ¿ÀÛ»óÅÂ¿Í µ¥ÀÌÅÍ »çº»(mirror) »ý¼ºÀÇ ¿©ºÎ µîÀ» ¾Ë·ÁÁÝ´Ï´Ù.

À籸¼º °úÁ¤Àº I/O ´ë¿ªÆøÀÇ »ç¿ëµÇÁö ¾Ê´Â ºÎºÐ¸¸À» »ç¿ëÇϹǷΠµð½ºÅ©ÀÇ ÀÛµ¿ LED °¡ ±ôºý¿©µµ ½Ã½ºÅÛÀÇ ¹ÝÀÀ ¼Óµµ¿¡ Å« ¿µÇâÀº ¾ø½À´Ï´Ù.

¿©·¯ºÐÀº À籸¼º °úÁ¤°ú´Â »ó°ü¾øÀÌ RAID ÀåÄ¡¸¦ »ç¿ëÇÒ ¼ö ÀÖ½À´Ï´Ù.

À籸¼ºÀÌ ÁøÇàÁßÀ϶§ Æ÷¸ËÀ» Çغ¸½Ê½Ã¿À. Àß µÉ °Ì´Ï´Ù. ¸¶¿îÆ®µµ ¹°·Ð ÇÒ ¼ö ÀÖ½À´Ï´Ù. ÇÏÁö¸¸ À籸¼ºÀ» ÇÏ´Â µµÁß¿¡ µð½ºÅ©¿¡ Àå¾Ö°¡ ¹ß»ýÇÏ¸é ¾î¿ µµ¸®°¡ ¾ø½À´Ï´Ù.

4.5 RAID-4

ÁÖÀÇ: - ÇÊÀÚµµ RAID-4ÀÇ ¼Â¾÷Àº Çغ¸Áö ¾Ê¾Ò½À´Ï´Ù. ÀÌ ºÎºÐ¸¸Å­Àº Á¦°¡ °æÇèÇÏÁö ¾ÊÀº ºÎºÐÀÔ´Ï´Ù. RAID-4¸¦ »ç¿ëÇÏ°í °è½Ã´Ù¸é ´ÙÀ½ À̸ÞÀÏ ÁÖ¼Ò·Î ¿©·¯ºÐÀÇ °æÇèÀ» ¾Ë·ÁÁֽñ⠹ٶø´Ï´Ù. author

ºñ½ÁÇÑ Å©±âÀÇ ¼¼ °³ ÀÌ»óÀÇ µð½ºÅ©°¡ ÀÖ°í ±× Áß Çϳª°¡ ³ª¸ÓÁöº¸´Ù ¼Óµµ°¡ ¿ùµîÈ÷ ºü¸¦¶§ µð½ºÅ©¸¦ Çϳª·Î ÇÕÃļ­ ¾²¸é¼­ µ¥ÀÌÅÍÀÇ ÀÌÁßÈ­µµ ²ÒÇÏ´Â °æ¿ì°¡ µÇ°Ú½À´Ï´Ù.

/etc/raidtab ÆÄÀÏÀÇ ³»¿ë:

raiddev /dev/md0
        raid-level      4
        nr-raid-disks   4
        nr-spare-disks  0
        persistent-superblock 1
        chunk-size      32
        device          /dev/sdb1
        raid-disk       0
        device          /dev/sdc1
        raid-disk       1
        device          /dev/sdd1
        raid-disk       2
        device          /dev/sde1
        raid-disk       3
¿¹ºñ µð½ºÅ©°¡ ÀÖÀ¸¸é °°Àº ¹æ¹ýÀ¸·Î Ãß°¡ÇØ ÁÖ½Ã¸é µË´Ï´Ù.
        device         /dev/sdf1
        spare-disk     0
RAID ÃʱâÈ­¸¦ ÇÕ´Ï´Ù.
   mkraid /dev/md0
Æ÷¸ËÀ» ÇϽñâ Àü¿¡ mke2fs ¸í·ÉÀÇ ¿É¼Ç¿¡ °üÇÑ ºÎºÐÀ» ²À Àо½Ê½Ã¿À.

4.6 RAID-5

ºñ½ÁÇÑ Å©±âÀÇ µð½ºÅ©°¡ ¼¼ °³ ÀÌ»óÀÖ°í µð½ºÅ©µéÀ» Çϳª·Î ÇÕÃÄ »ç¿ëÇϸ鼭 µ¥ÀÌÅÍÀÇ ÀÌÁßÈ­¸¦ ÇÏ·Á´Â °æ¿ìÀÔ´Ï´Ù. ¿¹ºñ µð½ºÅ©´Â Æò»ó½Ã¿£ »ç¿ëµÇÁö ¾Ê´Ù°¡ ´Ù¸¥ µð½ºÅ©¿¡ Àå¾Ö°¡ ¹ß»ýÇÏ¸é »ç¿ëµË´Ï´Ù.

N °³ÀÇ µð½ºÅ©°¡ ÀÖ°í ±× Áß °¡Àå ÀÛÀº µð½ºÅ©ÀÇ Å©±â°¡ S ¶ó°í Çϸé, Àüü RAIDÀÇ Å©±â´Â (N-1)*S °¡ µË´Ï´Ù. ¿ø·¡ µð½ºÅ©ÀÇ ÇÕº¸´Ù ÁÙ¾îµå´Â °ø°£Àº µ¥ÀÌÅÍ ÀÌÁßÈ­¸¦ À§ÇÑ Æи®Æ¼ Á¤º¸°¡ ÀúÀåµÇ´Â µ¥ »ç¿ëµË´Ï´Ù. ÀÌ ´öÅÿ¡ ÇϳªÀÇ µð½ºÅ©¿¡ Àå¾Ö°¡ ¹ß»ýÇÏ´õ¶óµµ µ¥ÀÌÅÍ´Â ¾ÈÀüÇÕ´Ï´Ù. ÇÏÁö¸¸ µÎ °³ ÀÌ»óÀÇ µð½ºÅ©¿¡ Àå¾Ö°¡ ¹ß»ýÇÏ¸é µ¥ÀÌÅÍ°¡ ¼Õ½ÇµË´Ï´Ù.

/etc/raidtab ÆÄÀÏÀÇ ³»¿ëÀÔ´Ï´Ù:

raiddev /dev/md0
        raid-level      5
        nr-raid-disks   7
        nr-spare-disks  0
        persistent-superblock 1
        parity-algorithm        left-symmetric
        chunk-size      32
        device          /dev/sda3
        raid-disk       0
        device          /dev/sdb1
        raid-disk       1
        device          /dev/sdc1
        raid-disk       2
        device          /dev/sdd1
        raid-disk       3
        device          /dev/sde1
        raid-disk       4
        device          /dev/sdf1
        raid-disk       5
        device          /dev/sdg1
        raid-disk       6
¿¹ºñ µð½ºÅ©°¡ ÀÖÀ¸¸é ¿ª½Ã °°Àº ¹æ¹ýÀ¸·Î Ãß°¡ÇØ ÁÖ½Ã¸é µË´Ï´Ù.
        device         /dev/sdh1
        spare-disk     0
´ëü·Î chunk size ´Â 32 kB °¡ Àû´çÇÕ´Ï´Ù. À§ÀÇ ¿¹Á¦´Â 7 °³ÀÇ 6 GB µð½ºÅ©·Î ±¸¼ºµÇ¾úÀ¸¸ç ÃÑ 36 GB ÀÇ ÀúÀå°ø°£À» °¡Áö°Ô µË´Ï´Ù.(°ø½ÄÀ» »ç¿ë, °è»êÇϸé (n-1)*s = (7-1)*6 = 36) ÀÌ´Â 4 kB ºí·Ï»çÀÌÁîÀÇ ext2 ÆÄÀϽýºÅÛÀ» »ç¿ëÇÕ´Ï´Ù. ´õ Å« ÆÄÀÏ ½Ã½ºÅÛÀ» »ç¿ëÇϰųª ¸Å¿ì Å« ÆÄÀÏÀ» ÀúÀåÇϽ÷Á¸é chunk-size ¿Í filesystem block-size ÀÇ °ªÀ» ´õ ´Ã·ÁÁÖ½Ã¸é µË´Ï´Ù.

ÀÌÁ¦ ´ÙÀ½À» ½ÇÇàÇϽʽÿÀ.

  mkraid /dev/md0
µð½ºÅ©µéÀÌ À籸¼ºÀ» ÇÏ´À¶ó°í Á¤½Å¾øÀÌ ÀÛµ¿ÇÒ °Ì´Ï´Ù. /proc/mdstat ÆÄÀÏÀ» ÅëÇØ °úÁ¤À» ÁöÄѺ¸½Ê½Ã¿À.

À籸¼º °úÁ¤ÀÌ ¿Ï·áµÇ±â Àü±îÁö´Â ¾ÆÁ÷ ³¡³­ °ÍÀÌ ¾Æ´Õ´Ï´Ù. ÇÏÁö¸¸ À籸¼ºÀÌ ÁøÇàµÇ´Â Áß¿¡µµ ¸ðµç ÀÛ¾÷À» ÇÒ ¼ö ÀÖ½À´Ï´Ù.(µð½ºÅ© Àå¾Ö°¡ ¹ß»ýÇÏ´Â °æ¿ì´Â Á¦¿Ü)

Æ÷¸ËÀ» ÇϽñâ Àü¿¡ mke2fs ¸í·ÉÀÇ ¿É¼Ç¿¡ °üÇÑ ºÎºÐÀ» ²À Àо½Ê½Ã¿À.

ÀÌÁ¦ ¿©·¯ºÐÀº ¾ðÁ¦µçÁö ´ÙÀ½ ¸í·É¾î·Î RAID ÀåÄ¡¸¦ Á¤Áö/°¡µ¿ÇÒ ¼ö ÀÖ½À´Ï´Ù.

  raidstop /dev/md0
¶Ç´Â
  raidstart /dev/md0
µÚ¿¡ ¼³¸íµå¸± autodetection ±â´ÉÀ» »ç¿ëÇϸé init- ÆÄÀÏ¿¡ À̸¦ Ãß°¡ÇÏ½Ç ÇÊ¿ä°¡ ¾ø½À´Ï´Ù.

4.7 Persistent Superblock

RAID °ü·Ã ÇÁ·Î±×·¥ÀÌ /etc/raidtab ÆÄÀÏÀ» Àоîµé¿©¼­ RAID¸¦ ÃʱâÈ­ÇÕ´Ï´Ù. ÇÏÁö¸¸ ÀÌ´Â /etc/raidtab ÆÄÀÏÀÌ ÀÖ´Â ÆÄƼ¼ÇÀÌ ¸¶¿îÆ®µÇ¾î ÀÖ´Â »óȲÇÏ¿¡¼­¸¸ °¡´ÉÇÑ ÀÏÀÔ´Ï´Ù. ÀÌ ¹®Á¦ ¶§¹®¿¡ RAID ÀåÄ¡·Î ºÎÆ®ÇÏ´Â ÀÏÀÌ º¹ÀâÇØÁý´Ï´Ù.

¶ÇÇÑ RAID ÀåÄ¡¿¡ ÀÖ´Â ÆÄÀϽýºÅÛÀ» ¸¶¿îÆ®ÇÒ ¶§¿¡µµ /etc/fstab ÆÄÀÏÀ» ÅëÇØÇÏ´Â °ÍÀÌ ¾Æ´Ï¶ó init ½ºÅ©¸³Æ®¸¦ ÀÌ¿ëÇØ¾ß ÇÕ´Ï´Ù.

persistent superblock ÀÌ ÀÌ ¹®Á¦¸¦ ÇØ°áÇÕ´Ï´Ù. /etc/raidtab ÆÄÀÏ¿¡¼­ persistent-superblock ¿É¼ÇÀ¸·Î ¼³Á¤µÇ¾îÀÖÀ¸¸é file, RAIDÀÇ Ã¹¹ø° µð½ºÅ©ÀÇ ½ÃÀۺκп¡ Ưº°ÇÑ superblock À» ±â·ÏÇØ µÎ°ÔµË´Ï´Ù. À̸¦ ÅëÇØ Ä¿³ÎÀÌ µð½ºÅ©·ÎºÎÅÍ ¹Ù·Î RAIDÀÇ ¼³Á¤ Á¤º¸¸¦ ÀоîµéÀÌ°Ô µÇ´Â °ÍÀÔ´Ï´Ù.

±×·¡µµ /etc/raidtab ÆÄÀÏÀº ³ªÁß¿¡ ÇÊ¿äÇÒ Áöµµ ¸ð¸£´Â À籸¼ºÀ» À§ÇØ °è¼Ó À¯ÁöÇؾßÇÕ´Ï´Ù.

½Ã½ºÅÛÀÌ ºÎÆ®µÇ¸é¼­ RAID¸¦ ÀÚµ¿À¸·Î ÀνÄÇÏ°Ô ÇÏ·Á¸é persistent superblock ¿É¼ÇÀ» Äѵξî¾ß ÇÕ´Ï´Ù. ´õ ÀÚ¼¼ÇÑ ¼³¸íÀº Autodetection ºÎºÐ¿¡¼­ ÇÕ´Ï´Ù.

4.8 Chunk size

chunk-size ´Â Áß¿äÇÕ´Ï´Ù. µð½ºÅ©¿¡ ±â·ÏÇÏ´Â ÀÛ¾÷Àº ¿Ïº®ÇÑ º´·Ä·Î ÇÒ ¼ö ÀÖ´Â °Ô ¾Æ´Õ´Ï´Ù. µÎ µð½ºÅ©°¡ ÀÖ°í ÇÑ ¹ÙÀÌÆ®¸¦ ¾²°íÀÚ ÇÑ´Ù¸é °¢ µð½ºÅ©¿¡ 4ºñÆ®¾¿ ±â·ÏµÉ °ÍÀ̸ç ÇÑ ºñÆ®¾¿ 0¹ø µð½ºÅ©¿Í 1¹ø µð½ºÅ©¿¡ ¹ø°¥¾Æ°¡¸ç ±â·ÏµÉ °ÍÀÔ´Ï´Ù. ÀÌ´Â Çϵå¿þ¾î¿¡¼­ Á¦¾îÇÏ´Â °ÍÀÌ ¾Æ´Ï¶ó ¿ì¸®°¡ ÁöÁ¤ÇØ ÁÖ´Â chunk-size, ÇÑ ÀåÄ¡¿¡ ±â·ÏµÇ´Â ÃÖ¼Ò µ¥ÀÌÅÍ·®À» Á¤ÇØÁÜÀ¸·Î½á °¡´ÉÇØÁö´Â °ÍÀÔ´Ï´Ù. RAID-0 ½Ã½ºÅÛÀ̶ó¸é chunk-size°¡ 4 kB À϶§ 16 kB Å©±âÀÇ µ¥ÀÌÅÍ´Â 4 kB ·Î ³× µîºÐµÇ¾î ù¹ø°¿Í ¼¼¹ø° 4 kB °¡ 0¹ø µð½ºÅ©¿¡, µÎ¹ø°¿Í ³×¹ø° 4 kB °¡ 1¹ø µð½ºÅ©¿¡ ±â·ÏµÇ°Ô µË´Ï´Ù. ±×·¯¹Ç·Î ´ë¿ë·®ÀÇ ¾²±â ÀÛ¾÷À» ÇÑ´Ù¸é chunk-size ¸¦ Å©°Ô ÇÔÀ¸·Î½á ¿À¹öÇìµå¸¦ ÁÙÀÏ ¼ö ÀÖ½À´Ï´Ù.

chunk-size ´Â ¸ðµç RAID ·¹º§(linear ¸ðµå Æ÷ÇÔ)¿¡¼­ ¸í½ÃµÇ¾î¾ß ÇÕ´Ï´Ù. ÇÏÁö¸¸ linear ¸ðµå¿¡¼­´Â chunk-size °¡ ¾Æ¹«·± ¿µÇâÀ» ³¢Ä¡Áö ¾Ê½À´Ï´Ù.

block-size ¿Í chunk-size ¸¦ Àß Á¶ÀýÇϸé ÃÖÀûÀÇ ¼º´ÉÀ» ¾òÀ» ¼ö ÀÖ½À´Ï´Ù.

/etc/raidtab ÆÄÀÏÀÇ chunk-size ¿É¼ÇÀº ų·Î¹ÙÀÌÆ® ´ÜÀ§ÀÔ´Ï´Ù. Áï 4 ´Â 4 kB ¸¦ ¶æÇÕ´Ï´Ù.

RAID-0

µ¥ÀÌÅÍ´Â º´·ÄÀûÀ¸·Î ±â·ÏµË´Ï´Ù. Á» ´õ ¸íÈ®È÷ ¸»Çϸé chunk-size Å©±â¸¸Å­¾¿ °¢ µð½ºÅ©¿¡ µ¹¾Æ°¡¸é¼­ ±â·ÏµË´Ï´Ù.

chunk-size °¡ 4 kB ÀÏ ¶§ 16 kB °¡ ¼¼ °³ÀÇ µð½ºÅ©¿¡ ±â·ÏµÈ´Ù¸é RAID ´Â µð½ºÅ© 0, 1, 2 ¿¡ 4 kB ¸¦ º´·ÄÀûÀ¸·Î ±â·ÏÇÏ°í ³ª¸ÓÁö 4 kB ¸¦ 0¹ø µð½ºÅ©¿¡ ±â·ÏÇÏ°Ô µË´Ï´Ù.

´ëü·Î 32 kB ÀÇ chunk-size °¡ Àû´çÇÕ´Ï´Ù. ÇÏÁö¸¸ ÃÖÀû°ªÀº RAID¸¦ ±¸¼ºÇÏ´Â µð½ºÅ©ÀÇ °¹¼ö¿Í ±â·ÏµÇ´Â ÆÄÀÏÀÇ Å©±â µî¿¡ µû¶ó ´Þ¶óÁý´Ï´Ù. °ªÀ» º¯°æÇØ °¡¸ç ÃÖÀûÀÇ ¼öÄ¡¸¦ ã¾Æ¾ß ÇÕ´Ï´Ù.

ext2 ÆÄÀϽýºÅÛ°ú RAID-0

ÀÌ ÆÁÀº michael@freenet-ag.de°¡ º¸³»ÁÖ¾ú½À´Ï´Ù.

ext2 ÆÄÀϽýºÅÛÀÇ ºí·Ï ±×·ìÀÇ ½ÃÀÛ ºÎºÐ¿¡´Â ´Ù¸¥ ºÎºÐº¸´Ù ´õ ¸¹Àº µð½ºÅ© ¾×¼¼½º°¡ ÀϾ´Ï´Ù. µð½ºÅ©°¡ ÇϳªÀÏ ¶§¿¡´Â ¹®Á¦°¡ µÇÁö ¾ÊÁö¸¸ RAID-0 ¿¡¼­ ¸ðµç ºí·Ï ±×·ìÀÌ °°Àº µð½ºÅ©¿¡ ¸ð¿© ÀÖÀ¸¸é ¹®Á¦°¡ µÉ ¼ö ÀÖ½À´Ï´Ù. ±× ¿¹·Î:

4k stripe size µµ 4k ÀÌ°í block size µµ 4k À̸é, ÇϳªÀÇ ºí·ÏÀÌ ÇϳªÀÇ stripe ÀÌ µË´Ï´Ù. µÎ °³ÀÇ µð½ºÅ©¿¡¼­´Â stripe-#disk-product ´Â 2*4k=8k °¡ µË´Ï´Ù. ±âº» block group size °¡ 32768 block À̸é, ¸ðµç ºí·Ï ±×·ìÀº 0¹ø µð½ºÅ©¿¡¼­ ½ÃÀ۵˴ϴÙ. ÀÌ ºÎºÐÀÌ ÀüüÀûÀÎ ¼º´ÉÀ» ÀúÇϽÃÅ°´Â hot spot ÀÌ µÇ´Â °ÍÀÔ´Ï´Ù. ¾Æ½±°Ôµµ block group size ´Â 8 blocks ´ÜÀ§·Î(4k block À϶§´Â 32k ´ÜÀ§·Î)¸¸ Á¶Á¤ÇÒ ¼ö ÀÖ½À´Ï´Ù. ±×·¸±â ¶§¹®¿¡ ´Ü¼øÈ÷ mkfs ÀÇ -g ¿É¼ÇÀ¸·Î block group size ¸¦ Á¶Á¤ÇÏ´Â °Í¸¸À¸·Î´Â ÀÌ ¹®Á¦¸¦ ÇØ°áÇÒ ¼ö ¾ø½À´Ï´Ù.

µð½ºÅ©¸¦ Ãß°¡Çϸé stripe-#disk-product´Â 12°¡ µÇ¹Ç·Î ù¹ø° ºí·ÏÀº 0¹ø µð½ºÅ©¿¡ ÀúÀåµÇ°í µÎ¹ø° ºí·ÏÀº 2¹ø µð½ºÅ©¿¡ ÀúÀåµÇ¸ç ¼¼¹ø° ºí·ÏÀº 1¹ø µð½ºÅ©¿¡ ÀúÀåµÇ°Ô µË´Ï´Ù. ºí·Ï ±×·ìÀÇ ½ÃÀۺκп¡¼­ µð½ºÅ© È°µ¿À¸·Î »ý±â´Â ºÎÇÏ´Â °¢°¢ÀÇ µð½ºÅ©¿¡ ºÐ»êµÇ°Ô µË´Ï´Ù.

µð½ºÅ©¸¦ Ãß°¡ÇÏÁö ¸øÇÏ´Â »óȲÀ̶ó¸é stripe size ¸¦ 32k ·Î Çغ¸½Ê½Ã¿À. stripe-#disk-product´Â 64k °¡ µÉ°Ì´Ï´Ù. ºí·Ï ±×·ìÀÇ Å©±â¸¦ 8 ºí·Ï ´ÜÀ§(32k)·Î ¹Ù²Ü¼ö ÀÖÀ¸¹Ç·Î 32760ÀÇ ºí·Ï ±×·ì »çÀÌÁî°¡ ¾Ë¸ÂÀ» °ÍÀÔ´Ï´Ù.

ºí·Ï ±×·ì °æ°è´Â stripe °æ°è¿Í ¸Â¾Æ ¶³¾îÁ®¾ßÇÕ´Ï´Ù. À§ÀÇ ¿¹Á¦¿¡¼­´Â ¹®Á¦°¡ µÇÁö ¾ÊÁö¸¸ stripe size °¡ Å« °æ¿ì¿¡´Â ¹®Á¦°¡ µÉ ¼ö ÀÖ½À´Ï´Ù.

RAID-1

chunk-size´Â µð½ºÅ©¿¡ ¾²±âÀÛ¾÷À» ÇÒ ¶§´Â º° Àǹ̰¡ ¾øÁö¸¸ Àб⸦ ÇÒ ¶§´Â ¾î·¹À̷κÎÅÍ ¾ó¸¶¸¸Å­¾¿ ¿¬¼ÓÀûÀ¸·Î Àоîµé¿©¿Í¾ß ÇÒ Áö¸¦ °áÁ¤ÇϹǷΠÁß¿äÇÕ´Ï´Ù. ¸ðµç µð½ºÅ©°¡ µ¿ÀÏÇÑ ³»¿ëÀ» ´ã°í ÀÖÀ¸¹Ç·Î ¾î¶² µð½ºÅ©¿¡¼­ Àоîµé¿©ÇÏÇϴ°¡ ÇÏ´Â °ÍÀº RAID °èÃþ¿¡¼­ ¾Ë¾Æ¼­ ÇÏ°Ô µË´Ï´Ù. ÀÌ µ¿ÀÛÀº Æò±Õ seek timeÀ» °³¼±Çϱâ À§ÇØ ¿øÇÏ´Â µ¥ÀÌÅÍ¿¡ Çìµå°¡ °¡Àå °¡±îÀÌ ÀÖ´Â µð½ºÅ©¸¦ ¼±ÅÃÇÏ°Ô µË´Ï´Ù.

RAID-4

RAID-4 ¿¡ ¾²±âÀÛ¾÷ÀÌ ¼öÇàµÈ ÈÄ¿¡´Â Æи®Æ¼ µð½ºÅ©ÀÇ Æи®Æ¼ Á¤º¸°¡ °»½ÅµÇ¾î¾ß ÇÕ´Ï´Ù.

RAID-4 ÀÇ Àбâ´Â RAID-0 °ú µ¿ÀÏÇϹǷΠRAID-4ÀÇ chunk-sizes ¿ª½Ã Àб⠼º´É¿¡ ¿µÇâÀ» ³¢Ä¨´Ï´Ù.

RAID-5

RAID-5ÀÇ Àбâ ÀÛ¾÷¿¡¼­ÀÇ chunk size´Â RAID-0 ¿¡¼­¿Í Àǹ̰¡ °°½À´Ï´Ù. ´Ù¸¸ RAID-5 ¿¡¼­ÀÇ ¾²±â ÀÛ¾÷Àº Á» ´õ º¹ÀâÇÕ´Ï´Ù. RAID-5¿¡ µ¥ÀÌÅÍ°¡ ±â·ÏµÇ¸é ÇØ´ç Æи®Æ¼µµ °»½ÅµÇ¾î¾ß ÇÕ´Ï´Ù. Æи®Æ¼¸¦ °»½ÅÇÏ·Á¸é ´ÙÀ½ÀÌ ÇÊ¿äÇÕ´Ï´Ù.

  • ±âÁ¸ µ¥ÀÌÅÍ, °»½ÅµÈ µ¥ÀÌÅÍ, ±âÁ¸ Æи®Æ¼ ºí·Ï
  • ¶Ç´Â Æи®Æ¼ µ¥ÀÌÅ͸¦ Á¦¿ÜÇÑ stripe ³»ÀÇ ¸ðµç µ¥ÀÌÅÍ
RAID ´Â ¾²±â ÀÛ¾÷À» ÁøÇàÇϸ鼭 °¡Àå ÀÌ»óÀûÀÎ ¹æ¹ýÀ» ÅëÇØ °¢ Æи®Æ¼¸¦ °»½ÅÇÏ°Ô µË´Ï´Ù. ½Ã½ºÅÛÀÌ ÃæºÐÇÑ ¸Þ¸ð¸®¸¦ °®°í ÀÖ°í ¾²±âÀÛ¾÷ÀÌ ÇÑ ÁÙ·Î ÁøÇàµÈ´Ù¸é Æи®Æ¼ °»½Å¿¡ µå´Â ¿À¹öÇìµå´Â RAID-1¿¡¼­ ó·³ ÀÛÀ» °Ì´Ï´Ù. ÀÌ °æ¿ì Æи®Æ¼ °è»êÀº ¸Å¿ì ½¬¿ì¹Ç·Î CPU¿¡ ÁÖ´Â ºÎ´ãÀº ¹«½ÃÇÒ ¼ö ÀÖÀ» Á¤µµ·Î ÀÛ½À´Ï´Ù. ÇÏÁö¸¸ ¾²±â ÀÛ¾÷ÀÌ RAIDÀü¹Ý¿¡ °ÉÃÄ Á¡´ÜÀ§·Î ºÐ»êµÇ¾î ¼öÇàµÈ´Ù¸é Æи®Æ¼ °è»êÀ» À§ÇØ °¢ stripe ¸¶´Ù Àбâ ÀÛ¾÷À» ¼öÇàÇØ¾ß ÇϹǷΠ¿À¹öÇìµå°¡ Ä¿Áö°Ô µË´Ï´Ù.

Åë»óÀûÀ¸·Î RAID-5 ¿¡¼­ÀÇ Àû´çÇÑ chunk-size´Â 128 kB ÀÔ´Ï´Ù.

mke2fsÀÇ ¿É¼Ç¿¡ ´ëÇØ ¼³¸íÇÑ ºÎºÐµµ Âü°íÇϽñ⠹ٶø´Ï´Ù. ÀÌ´Â RAID-5 ÀÇ ¼º´É°ú °ü°è°¡ ÀÖ½À´Ï´Ù.

4.9 mke2fs ÀÇ ¿É¼Ç

mke2fs·Î RAID-4 ³ª RAID-5 ÀåÄ¡¸¦ Æ÷¸ËÇÒ ¶§ ¾µ ¼ö Àִ Ưº°ÇÑ ¿É¼ÇÀÌ ÀÖ½À´Ï´Ù. -R stride=nn ¿É¼ÇÀº mke2fs ¸¦ ½ÇÇàÇÒ ¶§ RAID ÀåÄ¡¿¡ ÀûÇÕÇÑ ext2 µ¥ÀÌÅÍ ±¸Á¶·Î ÀúÀåÇÏ°Ô ÇØÁÝ´Ï´Ù.

chunk-size °¡ 32 kB ¶õ °ÍÀº 32 kB ¸¸Å­ ¿¬¼ÓÀûÀ¸·Î µð½ºÅ©¿¡ µ¥ÀÌÅÍ°¡ ±â·ÏµÈ´Ù´Â ¶æÀÔ´Ï´Ù. ext2 ÆÄÀϽýºÅÛ¿¡ 4kB ·Î block-size¸¦ Á¤ÇÏ°Ô µÇ¸é, 8°³ÀÇ ÆÄÀϽýºÅÛ ºí·ÏÀÌ ÇϳªÀÇ array chunk¿¡ ±â·ÏµÇ°Ô µË´Ï´Ù. ÆÄÀϽýºÅÛÀ» »ý¼ºÇÒ ¶§ ¾²´Â mke2fs ·Î ÀÌ·¸°Ô ÁöÁ¤ÇÒ ¼ö ÀÖ½À´Ï´Ù.

  mke2fs -b 4096 -R stride=8 /dev/md0

RAID-{4,5} ÀÇ ¼º´ÉÀº ÀÌ ¿É¼Ç¿¡ Å« ¿µÇâÀ» ¹Þ½À´Ï´Ù.

ext2fs ÀÇ blocksize ´Â ÆÄÀϽýºÅÛÀÇ ¼º´É¿¡ Áß´ëÇÑ ¿µÇâÀ» ¹ÌĨ´Ï´Ù. ÆÄÀϽýºÅÛÀÇ Å©±â°¡ ¼ö¹é¸Þ°¡¹ÙÀÌÆ® ÀÌ»óÀ̶ó¸é Ç×»ó 4kB ÀÇ block size ¸¦ »ç¿ëÇϽʽÿÀ. (¸¹Àº ¼öÀÇ ÀÛÀº ÆÄÀÏÀ» »ç¿ëÇÏ´Â °æ¿ì´Â Á¦¿Ü)

4.10 Autodetection

Autodetection Àº ½Ã½ºÅÛ ºÎÆýÿ¡ RAID ÀåÄ¡°¡ ÀÚµ¿À¸·Î ÀÎ½ÄµÇ°Ô ÇÕ´Ï´Ù.

ÀÌ ±â´ÉÀ» »ç¿ëÇÏ·Á¸é:

  1. Ä¿³ÎÀÌ autodetection ±â´ÉÀ» Áö¿øÇØ¾ß ÇÕ´Ï´Ù.
  2. RAID ÀåÄ¡°¡ persistent-superblock À» »ç¿ëÇÏ°Ô²û ¼³Á¤ÇØ¾ß ÇÕ´Ï´Ù.
  3. RAID ¸¦ ±¸¼ºÇÏ´Â µð½ºÅ©ÀÇ ÆÄƼ¼Ç ŸÀÔÀÌ 0xFD À̾î¾ß ÇÕ´Ï´Ù.(fdisk ¿¡¼­ type À» ``fd''·Î ¼³Á¤)

ÁÖÀÇ:ÆÄƼ¼Ç ŸÀÔÀ» ¹Ù²Ù·Á¸é RAID¸¦ ¸ØÃß¾î¾ß ÇÕ´Ï´Ù. raidstop /dev/md0¸í·ÉÀ¸·Î RAID¸¦ Á¤ÁöÇϽʽÿÀ.

autodetection ±â´ÉÀÌ µ¿ÀÛÇÏ°Ô µÇ¾ú½À´Ï´Ù. ½Ã½ºÅÛÀ» ´Ù½Ã ½ÃÀÛÇÏ°í /proc/mdstat ¸¦ ÅëÇØ RAID°¡ µ¿ÀÛÇϴ°¡ È®ÀÎÇϽʽÿÀ.

ºÎÆðúÁ¤¿¡¼­ º¸ÀÌ´Â ¸Þ½ÃÁö´Â ´ë·« ´ÙÀ½°ú °°½À´Ï´Ù:

 Oct 22 00:51:59 malthe kernel: SCSI device sdg: hdwr sector= 512
  bytes. Sectors= 12657717 [6180 MB] [6.2 GB]
 Oct 22 00:51:59 malthe kernel: Partition check:
 Oct 22 00:51:59 malthe kernel:  sda: sda1 sda2 sda3 sda4
 Oct 22 00:51:59 malthe kernel:  sdb: sdb1 sdb2
 Oct 22 00:51:59 malthe kernel:  sdc: sdc1 sdc2
 Oct 22 00:51:59 malthe kernel:  sdd: sdd1 sdd2
 Oct 22 00:51:59 malthe kernel:  sde: sde1 sde2
 Oct 22 00:51:59 malthe kernel:  sdf: sdf1 sdf2
 Oct 22 00:51:59 malthe kernel:  sdg: sdg1 sdg2
 Oct 22 00:51:59 malthe kernel: autodetecting RAID arrays
 Oct 22 00:51:59 malthe kernel: (read) sdb1's sb offset: 6199872
 Oct 22 00:51:59 malthe kernel: bind<sdb1,1>
 Oct 22 00:51:59 malthe kernel: (read) sdc1's sb offset: 6199872
 Oct 22 00:51:59 malthe kernel: bind<sdc1,2>
 Oct 22 00:51:59 malthe kernel: (read) sdd1's sb offset: 6199872
 Oct 22 00:51:59 malthe kernel: bind<sdd1,3>
 Oct 22 00:51:59 malthe kernel: (read) sde1's sb offset: 6199872
 Oct 22 00:51:59 malthe kernel: bind<sde1,4>
 Oct 22 00:51:59 malthe kernel: (read) sdf1's sb offset: 6205376
 Oct 22 00:51:59 malthe kernel: bind<sdf1,5>
 Oct 22 00:51:59 malthe kernel: (read) sdg1's sb offset: 6205376
 Oct 22 00:51:59 malthe kernel: bind<sdg1,6>
 Oct 22 00:51:59 malthe kernel: autorunning md0
 Oct 22 00:51:59 malthe kernel: running: <sdg1><sdf1><sde1><sdd1><sdc1><sdb1>
 Oct 22 00:51:59 malthe kernel: now!
 Oct 22 00:51:59 malthe kernel: md: md0: raid array is not clean -- starting background reconstruction 
ÀÌ Ãâ·Â¹°Àº RAID-5 °¡ ½Ã½ºÅÛÀÇ ºñÁ¤»óÀûÀÎ Á¾·áµîÀ¸·Î ÀÎÇØ ¿Ã¹Ù¸£°Ô ¼Ë´Ù¿î µÇÁö ¾Ê¾ÒÀ»¶§ ³ª¿À´Â °ÍÀÔ´Ï´Ù. À籸¼ºÀÌ ÀÚµ¿À¸·Î ½ÇÇàµË´Ï´Ù. Æи®Æ¼ Á¤º¸¸¸ ºÒÀÏÄ¡ÇÒ »Ó ½ÇÁ¦ µ¥ÀÌÅÍ¿¡´Â ÀÌ»óÀÌ ¾øÀ¸¹Ç·Î ÀÌ ÀåÄ¡´Â ¸¶¿îÆ®Çؼ­ »ç¿ëÇÒ ¼ö ÀÖ½À´Ï´Ù.

ºÎÆýÿ¡ ÀÚµ¿À¸·Î ÀÎ½ÄµÇ¸é ¼Ë´Ù¿îµµ ÀÚµ¿À¸·Î µË´Ï´Ù. init ½ºÅ©¸³Æ®¸¦ ½Å°æ¾µ ÇÊ¿äµµ ¾ø½À´Ï´Ù. ±×³É ´Ù¸¥ /dev/sd ³ª /dev/hd Àåġó·³ »ç¿ëÇÏ¸é µË´Ï´Ù.

init ½ºÅ©¸³Æ®¿¡ ÀÖ´Â raidstart/raidstop ¸í·ÉÀº old-style RAID¸¦ À§ÇÑ °ÍÀ̹ǷΠÁö¿öµµ ¹«¹æÇÕ´Ï´Ù.

4.11 Booting on RAID

There are several ways to set up a system that mounts it's root filesystem on a RAID device. Some distributions allow for RAID setup in the installation process, and this is by far the easiest way to get a nicely set up RAID system.

»õ·ÎÀº LILO ´Â RAID-1 ÀåÄ¡¸¦ Áö¿øÇϱ⶧¹®¿¡ RAID ÀåÄ¡·Î ºÎÅÍ Ä¿³ÎÀÌ ÀûÀçµÉ ¼ö ÀÖ½À´Ï´Ù. Newer LILO distributions can handle RAID-1 devices, and thus the kernel can be loaded at boot-time from a RAID device. LILO will correctly write boot-records on all disks in the array, to allow booting even if the primary disk fails.

The author does not yet know of any easy method for making the Grub boot-loader write the boot-records on all disks of a RAID-1. Please share your wisdom if you know how to do this.

Another way of ensuring that your system can always boot is, to create a boot floppy when all the setup is done. If the disk on which the /boot filesystem resides dies, you can always boot from the floppy. On RedHat and RedHat derived systems, this can be accomplished with the mkbootdisk command.

4.12 RAID ÀåÄ¡¿¡ À§Ä¡ÇÏ´Â ·çÆ® ÆÄÀϽýºÅÛ

RAID µð½ºÅ©·Î ºÎÆÃÇϱâÀ§Çؼ­´Â ·çÆ® ÆÄƼ¼Ç(/)ÀÌ RAIDµð½ºÅ©·Î ¸¶¿îÆ®µÇ¾î ÀÖ¾î¾ß ÇÕ´Ï´Ù. µÎ °¡Áö ¹æ¹ýÀÌ Àִµ¥ ÇÑ °¡Áö´Â RAID°¡ ¾Æ´Ñ µð½ºÅ©¿¡ ¼³Ä¡µÈ ·çÆ®ÆÄƼ¼ÇÀ» RAIDµð½ºÅ©·Î ¿Å±â´Â ¹æ¹ýÀÔ´Ï´Ù. ¿äÁòÀÇ ¹èÆ÷ÆÇ¿¡¼­´Â Ãʱ⠼³Ä¡½Ã¿¡ RAID¸¦ »ý¼ºÇؼ­ ¼³Ä¡ÇÒ ¼ö ÀÖÀ¸¹Ç·Î ÀÌ ¹æ¹ýÀº º° ¾µ¸ð°¡ ¾øÀ»°Ì´Ï´Ù. ÇÏÁö¸¸ ±âÁ¸ ½Ã½ºÅÛÀ» ÀÌ ¹æ¹ýÀ» ÀÌ¿ëÇؼ­ ÀÌÀüÇØ¾ß ÇÒ °æ¿ìµµ ÀÖÀ» °Ì´Ï´Ù. In order to have a system booting on RAID, the root filesystem (/) must be mounted on a RAID device. Two methods for achieving this is supplied bellow. The methods below assume that you install on a normal partition, and then - when the installation is complete - move the contents of your non-RAID root filesystem onto a new RAID device. Please not that this is no longer needed in general, as most newer GNU/Linux distributions support installation on RAID devices (and creation of the RAID devices during the installation process). However, you may still want to use the methods below, if you are migrating an existing system to RAID.

1¹ø ¹æ¹ý

This method assumes you have a spare disk you can install the system on, which is not part of the RAID you will be configuring.

  • First, install a normal system on your extra disk.
  • Get the kernel you plan on running, get the raid-patches and the tools, and make your system boot with this new RAID-aware kernel. Make sure that RAID-support is in the kernel, and is not loaded as modules.
  • Ok, now you should configure and create the RAID you plan to use for the root filesystem. This is standard procedure, as described elsewhere in this document.
  • Just to make sure everything's fine, try rebooting the system to see if the new RAID comes up on boot. It should.
  • Put a filesystem on the new array (using mke2fs), and mount it under /mnt/newroot
  • Now, copy the contents of your current root-filesystem (the spare disk) to the new root-filesystem (the array). There are lots of ways to do this, one of them is
     cd /
     find . -xdev | cpio -pm /mnt/newroot
    
  • You should modify the /mnt/newroot/etc/fstab file to use the correct device (the /dev/md? root device) for the root filesystem.
  • Now, unmount the current /boot filesystem, and mount the boot device on /mnt/newroot/boot instead. This is required for LILO to run successfully in the next step.
  • Update /mnt/newroot/etc/lilo.conf to point to the right devices. The boot device must still be a regular disk (non-RAID device), but the root device should point to your new RAID. When done, run
     lilo -r /mnt/newroot
    
    This LILO run should complete with no errors.
  • Reboot the system, and watch everything come up as expected :)

If you're doing this with IDE disks, be sure to tell your BIOS that all disks are ``auto-detect'' types, so that the BIOS will allow your machine to boot even when a disk is missing.

2¹ø ¹æ¹ý

This method requires that your kernel and raidtools understand the failed-disk directive in the /etc/raidtab file - if you are working on a really old system this may not be the case, and you will need to upgrade your tools and/or kernel first.

You can only use this method on RAID levels 1 and above, as the method uses an array in "degraded mode" which in turn is only possible if the RAID level has redundancy. The idea is to install a system on a disk which is purposely marked as failed in the RAID, then copy the system to the RAID which will be running in degraded mode, and finally making the RAID use the no-longer needed ``install-disk'', zapping the old installation but making the RAID run in non-degraded mode.

  • First, install a normal system on one disk (that will later become part of your RAID). It is important that this disk (or partition) is not the smallest one. If it is, it will not be possible to add it to the RAID later on!
  • Then, get the kernel, the patches, the tools etc. etc. You know the drill. Make your system boot with a new kernel that has the RAID support you need, compiled into the kernel.
  • Now, set up the RAID with your current root-device as the failed-disk in the raidtab file. Don't put the failed-disk as the first disk in the raidtab, that will give you problems with starting the RAID. Create the RAID, and put a filesystem on it.
  • Try rebooting and see if the RAID comes up as it should
  • Copy the system files, and reconfigure the system to use the RAID as root-device, as described in the previous section.
  • When your system successfully boots from the RAID, you can modify the raidtab file to include the previously failed-disk as a normal raid-disk. Now, raidhotadd the disk to your RAID.
  • You should now have a system that can boot from a non-degraded RAID.

4.13 RAID ÀåÄ¡¿¡¼­ ½Ã½ºÅÛÀÌ ºÎÆÃµÇ°Ô ¸¸µé±â

For the kernel to be able to mount the root filesystem, all support for the device on which the root filesystem resides, must be present in the kernel. Therefore, in order to mount the root filesystem on a RAID device, the kernel must have RAID support.

The normal way of ensuring that the kernel can see the RAID device is to simply compile a kernel with all necessary RAID support compiled in. Make sure that you compile the RAID support into the kernel, and not as loadable modules. The kernel cannot load a module (from the root filesystem) before the root filesystem is mounted.

However, since RedHat-6.0 ships with a kernel that has new-style RAID support as modules, I here describe how one can use the standard RedHat-6.0 kernel and still have the system boot on RAID.

Booting with RAID as module

You will have to instruct LILO to use a RAM-disk in order to achieve this. Use the mkinitrd command to create a ramdisk containing all kernel modules needed to mount the root partition. This can be done as:

 mkinitrd --with=<module> <ramdisk name> <kernel>
For example:
 mkinitrd --preload raid5 --with=raid5 raid-ramdisk 2.2.5-22

This will ensure that the specified RAID module is present at boot-time, for the kernel to use when mounting the root device.

4.14 Converting a non-RAID RedHat System to run on Software RAID

ÀÌ ºÎºÐÀÇ ³»¿ëÀº IBMÀÇ Mark Price °¡ º¸³»ÁØ ³»¿ëÀÔ´Ï´Ù.

¼Ò°³

RAID ¸¦ »ç¿ëÇÏÁö ¾Ê´ø ¸®´ª½º ½Ã½ºÅÛÀ» Software RAID ¸¦ »ç¿ëÇÏ´Â ½Ã½ºÅÛÀ¸·Î Å»¹Ù²ÞÇÏ´Â ¹æ¹ý¿¡ ´ëÇØ ¼³¸íÇÕ´Ï´Ù.

Scope

Redhat 7.1 ¿¡¼­ Å×½ºÆ®µÇ¾úÀ¸¸ç Software RAID (md) °¡ Áö¿øµÇ´Â ´Ù¸¥ ¹èÆ÷º»¿¡µµ Àû¿ë°¡´ÉÇÑ ³»¿ëÀÔ´Ï´Ù.

Pre-conversion example system

ÀÌ ½Ã½ºÅÛ¿¡´Â sda, sdb µÎ °³ÀÇ µ¿ÀÏÇÑ Å©±âÀÇ ½ºÄ«½Ã µð½ºÅ©°¡ ÀÖ½À´Ï´Ù. µÎ µð½ºÅ©´Â ¶È°°Àº ÆÄƼ¼Ç ¼³Á¤À» °¡Áö°í ÀÖÀ¸¸ç ºí·ÏÅ©±â±îÁöµµ µ¿ÀÏÇÕ´Ï´Ù.

DEVICE      MOUNTPOINT  SIZE        DEVICE      MOUNTPOINT  SIZE
/dev/sda1   /           2048MB      /dev/sdb1               2048MB
/dev/sda2   /boot       80MB        /dev/sdb2               80MB
/dev/sda3   /var/       100MB       /dev/sdb3               100MB
/dev/sda4   SWAP        1024MB      /dev/sdb4   SWAP        1024MB
ÀÌ ¿¹Á¦¿¡¼­´Â µÎ °³ÀÇ ¹°¸®Àû µð½ºÅ©·Î ±¸¼ºµÇ´Â RAID-1 (¹Ì·¯¸µ) À» ¼³Á¤ÇØ º¸°Ú½À´Ï´Ù.

1 ´Ü°è - rescue cd ³ª floppy ·Î ºÎÆÃÇϱâ

·¹µåÇÞ ¼³Ä¡ CD´Â rescue ¸ðµå·Î ºÎÆÃÇÏ¸é ½Ã½ºÅÛ¿¡¼­ ¹ß°ßµÇ´Â ¸ðµç ÆÄÀϽýºÅÛÀ» ¸¶¿îÆ®ÇÏ´Â ±â´ÉÀ» Á¦°øÇÕ´Ï´Ù.

lilo ÇÁ·ÒÇÁÆ®¿¡¼­ ´ÙÀ½À» ÀÔ·ÂÇÕ´Ï´Ù.

    lilo: linux rescue ide=nodma

À§¿Í °°ÀÌ ¼³Á¤À» Çϸé ÀνºÅç·¯°¡ ¾î¶² µð½ºÅ©¿¡ ·çÆ® ÆÄÀϽýºÅÛÀÌ µé¾îÀִ°¡¸¦ ¹°¾îº¸°Ô µË´Ï´Ù. ¿©±â¿¡¼­´Â sda ¸¦ ¼±ÅÃÇÏ½Ã¸é µË´Ï´Ù.

ÀνºÅç·¯´Â ´ÙÀ½°ú °°ÀÌ ÆÄÀϽýºÅÛÀ» ¸¶¿îÆ®ÇÕ´Ï´Ù.

DEVICE      MOUNTPOINT  TEMPORARY MOUNT POINT
/dev/sda1   /           /mnt/sysimage
/dev/sda2   /boot       /mnt/sysimage/boot
/dev/sda3   /var        /mnt/sysimage/var
/dev/sda6   /home       /mnt/sysimage/home

ÁÖÀÇ: - ´Ù¸¥ ¹èÆ÷º»Àº ¸¶¿îÆ® Æ÷ÀÎÆ®ÀÇ À̸§ÀÌ ´Ù¸£°Å³ª ¼öµ¿À¸·Î ¸¶¿îÆ®ÇØ¾ß ÇÏ´Â °æ¿ìµµ ÀÖ½À´Ï´Ù.

2 ´Ü°è - raidtab ÆÄÀÏ »ý¼ºÇϱâ

/mnt/sysimage/etc/raidtab ÆÄÀÏ(ȤÀº ±×¿¡ »óÀÀÇÏ´Â À§Ä¡ÀÇ ÆÄÀÏ)À» »ý¼ºÇÕ´Ï´Ù.

±× ¿¹´Â ´ÙÀ½°ú °°½À´Ï´Ù.

raiddev /dev/md0
    raid-level              1
    nr-raid-disks           2
    nr-spare-disks          0
    chunk-size              4
    persistent-superblock   1
    device                  /dev/sda1
    raid-disk               0
    device                  /dev/sdb1
    raid-disk               1

raiddev /dev/md1
    raid-level              1
    nr-raid-disks           2
    nr-spare-disks          0
    chunk-size              4
    persistent-superblock   1
    device                  /dev/sda2
    raid-disk               0
    device                  /dev/sdb2
    raid-disk               1

raiddev /dev/md2
    raid-level              1
    nr-raid-disks           2
    nr-spare-disks          0
    chunk-size              4
    persistent-superblock   1
    device                  /dev/sda3
    raid-disk               0
    device                  /dev/sdb3
    raid-disk               1

ÁÖÀÇ: - ÀåÄ¡µéÀ» ¿Ã¹Ù¸¥ ¼ø¼­·Î ¼³Á¤ÇÏ´Â °ÍÀÌ Áß¿äÇÕ´Ï´Ù. ±× ¿¹·Î /dev/sda1 °¡ raid-disk 0 ÀÔ´Ï´Ù. raid-disk 1 ÀÌ ¾Æ´Õ´Ï´Ù. ÀÌ ¼ø¼­´ë·Î md µå¶óÀ̹ö°¡ /dev/sda1ÀÇ µ¥ÀÌÅ͸¦ µ¿±âÈ­ÇØ ¿À°ÔµË´Ï´Ù. ÀÌ ¼ø¼­°¡ À߸øµÇ¸é ÆÄÀϽýºÅÛÀ» ¸ÁÄ¡°Ô µË´Ï´Ù.

ÀÌÁ¦ root ÆÄÀϽýºÅÛÀ» º¹»çÇØ ¿É´Ï´Ù.

(rescue)# cp /mnt/sysimage/etc/raidtab /etc/raidtab

3 ´Ü°è - md ÀåÄ¡ »ý¼ºÇϱâ

µÎ °¡Áö ¹æ¹ýÀÌ ÀÖ½À´Ï´Ù. /mnt/sysimage/dev ¿¡¼­ ÀåÄ¡ ÆÄÀÏÀ» º¹»çÇØ ¿À°Å³ª mknod ·Î ¸¸µé¸é µË´Ï´Ù. md ÀåÄ¡´Â major number°¡ 9 ÀÔ´Ï´Ù.

(rescue)# mknod /dev/md0 b 9 0
(rescue)# mknod /dev/md1 b 9 1
(rescue)# mknod /dev/md2 b 9 2

4 ´Ü°è - ÆÄÀϽýºÅÛ ¾ð¸¶¿îÆ®Çϱâ

raid ÀåÄ¡¸¦ ±âµ¿ÇÏ°í µ¿±âÈ­Çϱâ À§Çؼ­´Â ¸ÕÀú Àӽà ÆÄÀϽýºÅÛµéÀ» ¾ð¸¶¿îÆ®ÇØ¾ß ÇÕ´Ï´Ù.

(rescue)# umount /mnt/sysimage/var
(rescue)# umount /mnt/sysimage/boot
(rescue)# umount /mnt/sysimage/proc
(rescue)# umount /mnt/sysimage

5 ´Ü°è - raid ÀåÄ¡ ±âµ¿Çϱâ

/dev/sda1, /dev/sda2, /dev/sda3 ¿¡ ±âÁ¸ÀÇ ÆÄÀϽýºÅÛÀÌ ÀÖÀ¸¹Ç·Î raid ÀåÄ¡¸¦ °­Á¦·Î °¡µ¿½ÃÄÑ¾ß ÇÕ´Ï´Ù.

(rescue)# mkraid --really-force /dev/md2

ÁøÇà»óȲ, »óÅÂ, Áøôµµ µîÀ» /proc/mdstat ÆÄÀÏÀ» ÅëÇØ ¾Ë ¼ö ÀÖ½À´Ï´Ù.

/boot ¿Í / ÆÄÀϽýºÅÛµµ °°Àº ¹æ¹ýÀ» Àû¿ëÇÕ´Ï´Ù.

(rescue)# mkraid --really-force /dev/md1
(rescue)# mkraid --really-force /dev/md0

md µå¶óÀ̹ö´Â ÇÑ ¹ø¿¡ ÇÑ ÀåÄ¡¾¿ µ¿±âÈ­ÇÏ°Ô µË´Ï´Ù.

6 ´Ü°è - ÆÄÀϽýºÅÛµéÀ» ´Ù½Ã ¸¶¿îÆ®Çϱâ

ÀÌÁ¦ µ¿±âÈ­µÈ ÆÄÀϽýºÅÛµéÀ» /mnt/sysimage ·Î ¸¶¿îÆ®ÇÕ´Ï´Ù.

(rescue)# mount /dev/md0 /mnt/sysimage
(rescue)# mount /dev/md1 /mnt/sysimage/boot
(rescue)# mount /dev/md2 /mnt/sysimage/var

7 ´Ü°è- root µð·ºÅ丮 ¹Ù²Ù±â

ÇöÀç µð·ºÅ丮¸¦ ·çÆ® µð·ºÅ丮·Î ¹Ù²ß´Ï´Ù.

(rescue)# chroot /mnt/sysimage

8 ´Ü°è - ¼³Á¤ ÆÄÀÏ ¼öÁ¤Çϱâ

md µð¹ÙÀ̽º·Î ºÎÆÃÇÏ°í md µð¹ÙÀ̽º¸¦ ¸¶¿îÆ®ÇÏ·Á¸é /etc/fstab ÆÄÀÏÀ» ¾Ë¸Â°Ô º¯°æÇØ ÁÖ¾î¾ß ÇÕ´Ï´Ù.

ÁÖÀÇ: - boot device ´Â /dev/sda °¡ µÇ°í root device ´Â /dev/md0 ·Î ¼³Á¤ÇØ¾ß ÇÕ´Ï´Ù.

boot=/dev/sda
map=/boot/map
install=/boot/boot.b
prompt
timeout=50
message=/boot/message
linear
default=linux

image=/boot/vmlinuz
    label=linux
    read-only
    root=/dev/md0

/etc/fstab ÆÄÀÏÀ» ¼öÁ¤ÇÕ´Ï´Ù.

/dev/md0               /                       ext3    defaults        1 1
/dev/md1               /boot                   ext3    defaults        1 2
/dev/md2               /var                    ext3    defaults        1 2
/dev/sda4              swap                    swap    defaults        0 0

9 ´Ü°è - LILO ½ÇÇàÇϱâ

With the /etc/lilo.conf edited to reflect the new root=/dev/md0 and with /dev/md1 mounted as /boot, we can now run /sbin/lilo -v on the chrooted filesystem.

10 ´Ü°è - ÆÄƼ¼Ç ŸÀÔ ¹Ù²Ù±â

md ¸¦ ±¸¼ºÇÏ´Â µð½ºÅ©µéÀÇ ÆÄƼ¼Ç ŸÀÔÀº ¸ðµÎ 0xFD À̾î¾ß ÇÕ´Ï´Ù.

't' ¿É¼ÇÀ¸·Î ÆÄƼ¼ÇÀÇ Å¸ÀÔÀ» º¯°æÇÕ´Ï´Ù.

(rescue)# fdisk /dev/sda
(rescue)# fdisk /dev/sdb

'w' ¿É¼ÇÀ¸·Î º¯°æµÈ ÆÄƼ¼Ç Å×À̺íÀ» ÀúÀåÇÕ´Ï´Ù.

11 ´Ü°è - ÆÄÀϽýºÅÛ Å©±â º¯°æÇϱâ

raid ÀåÄ¡¸¦ »ý¼ºÇÏ°ÔµÇ¸é µÎ¹ø° ¼öÆÛºí·ÏÀÌ ÆÄƼ¼ÇÀÇ ³¡ºÎºÐ¿¡ ÀúÀåµÇ±â ¶§¹®¿¡ ¹°¸®Àû ÆÄƼ¼ÇÀÇ Å©±â°¡ ¾à°£ ÁÙ¾îµé°Ô µË´Ï´Ù. ÀÌ »óÅ¿¡¼­ ¸®ºÎÆÃÀ» ÇÏ°ÔµÇ¸é ¼öÆÛºí·ÏÀÌ ¼Õ»óµÆ´Ù´Â ¸Þ¼¼Áö°¡ ³ª¿À¸ç ºÎÆÃÀÌ µÇÁö ¾ÊÀ» °Ì´Ï´Ù.

±×·¡¼­ ÀçºÎÆÃÇϱâ Àü¿¡ ±× ºÎºÐÀ» Á¶Á¤ÇØ ÁÖ¾î¾ß ÇÕ´Ï´Ù. ·çÆ®ÆÄƼ¼ÇÀ» Á¦¿ÜÇÑ ¸ðµç md ±â¹Ý ÆÄÀϽýºÅÛÀÌ ¾ð¸¶¿îÆ® µÇ¾ú´ÂÁö È®ÀÎÇÏ°í ·çÆ®ÆÄƼ¼ÇÀ» read-only ·Î ¸¶¿îÆ®ÇϽʽÿÀ.

(rescue)# mount / -o remount,ro

¸ðµç md ÀåÄ¡¸¦ fsck Ç϶ó´Â ¸Þ¼¼Áö¸¦ º¸°Ô µÉ °ÍÀ̱⠶§¹®¿¡ ·çÆ®ÆÄƼ¼ÇÀ» Àбâ Àü¿ëÀ¸·Î ¸¶¿îÆ®ÇÏ´Â °Ì´Ï´Ù. -f ¿É¼ÇÀº ¹®Á¦°¡ ¾ø´Â ÆÄÀϽýºÅÛÀÏÁö¶óµµ °­Á¦·Î fsck ¸¦ ¼öÇàÇÏ°Ô ÇÕ´Ï´Ù.

(rescue)# e2fsck -f /dev/md0

ÀÌ ¸í·ÉÀº inconsistent sizes ¿Í ¼öÆÛºí·Ï ¼Õ»óÀ» ÀÌÀ¯·Î ¿¡·¯¸Þ¼¼Áö¸¦ ³»º¸³¾ °Ì´Ï´Ù. 'Abort?' ÇÏ·Á¸é N À» ÀÔ·ÂÇϽʽÿÀ.

(rescue)# resize2fs /dev/md0

ÇØ´çµÇ´Â ¸ðµç /dev/md ÀåÄ¡¿¡ À§ÀÇ ¸í·ÉÀ» ¹Ýº¹ Àû¿ëÇÕ´Ï´Ù.

12 ´Ü°è - Á¡°Ë»çÇ×

ÀÌÁ¦´Â ¸®ºÎÆÃÀ» ÇÒ Â÷·ÊÀÔ´Ï´Ù. ¸®ºÎÆÃÇϱâ Àü¿¡ ¾Æ·¡ ¸ñ·ÏÀ» ºüÁü ¾øÀÌ È®ÀÎÇϽʽÿÀ.

  • /proc/mdstat ÆÄÀÏÀ» ÅëÇØ ¸ðµç ÀåÄ¡°£ÀÇ sync °¡ ¿Ï·áµÇ¾ú´Â°¡ È®ÀÎ.
  • º¯°æµÈ »çÇ×ÀÌ /etc/fstab ÆÄÀÏ¿¡ Àß ¹Ý¿µµÇ¾ú´Â°¡ È®ÀÎ.
  • /etc/lilo.conf ÆÄÀÏÀÇ ·çÆ® µð¹ÙÀ̽º À̸§ÀÌ ¿Ã¹Ù¸£°Ô º¯°æµÇ¾ú´Â°¡ È®ÀÎ.
  • ºÎÆ® ·Î´õ¸¦ °»½ÅÇϱâ À§ÇØ /sbin/lilo ¸¦ ½ÇÇà.
  • Ä¿³Î¿¡ SCSI ¿Í RAID(MD) µå¶óÀ̹ö°¡ Æ÷ÇԵǾú´Â°¡ È®ÀÎ.
  • RAID ÀåÄ¡¸¦ ±¸¼ºÇÏ´Â µð½ºÅ©µéÀÇ ÆÄƼ¼Ç ŸÀÔÀÌ 0xfd ·Î º¯°æµÇ¾ú´Â°¡ È®ÀÎ.
  • RAID °¡ µÉ ÆÄÀϽýºÅÛ¿¡ ´ëÇØ fsck ¿Í resize2fs ¸¦ ½ÇÇàÇߴ°¡ È®ÀÎ.

13 ´Ü°è - ÀçºÎÆÃÇϱâ

ÀÌÁ¦ ¾ÈÀüÇÏ°Ô ½Ã½ºÅÛÀ» ÀçºÎÆÃÇÒ ¼ö ÀÖ½À´Ï´Ù. ½Ã½ºÅÛÀÌ ºÎÆõǸ鼭 ÀÚµ¿À¸·Î md ÀåÄ¡¸¦ ÀνÄÇÏ°Ô µË´Ï´Ù.

root ÆÄÀϽýºÅÛÀº ÀÌÁ¦ ¹Ì·¯¸µµÈ °Ì´Ï´Ù.

4.15 ÁÖÀÇ»çÇ×

µ¿ÀÛÁßÀÎ RAID ÀÇ ±¸¼º µð½ºÅ©ÀÇ ÆÄƼ¼ÇÀ» Àý´ë·Î ¹Ù²ÙÁö ¸¶½Ê½Ã¿À. ²À ±×·¡¾ß ÇÑ´Ù¸é RAID¸¦ ¸ØÃá´ÙÀ½ ÇϽʽÿÀ.

It is easy to put too many disks on a bus. A normal Fast-Wide SCSI bus can sustain 10 MB/s which is less than many disks can do alone today. Putting six such disks on the bus will of course not give you the expected performance boost. It is becoming equally easy to saturate the PCI bus - remember, a normal 32-bit 33 MHz PCI bus has a theoretical maximum bandwidth of around 133 MB/sec, considering command overhead etc. you will see a somewhat lower real-world transfer rate. Some disks today has a throughput in excess of 30 MB/sec, so just four of those disks will actually max out your PCI bus! When designing high-performance RAID systems, be sure to take the whole I/O path into consideration - there are boards with more PCI busses, with 64-bit and 66 MHz busses, and with PCI-X.

More SCSI controllers will only give you extra performance, if the SCSI busses are nearly maxed out by the disks on them. You will not see a performance improvement from using two 2940s with two old SCSI disks, instead of just running the two disks on one controller.

persistent-superblock ¿É¼ÇÀÌ ´©¶ôµÇ¾ú´Ù¸é array ¸¦ Á¤ÁöÇß´Ù°¡ ´Ù½Ã µ¿ÀÛ½Ãų¶§ µÇÁö ¾ÊÀ» °Ì´Ï´Ù. raidtab ¿¡ ¿É¼ÇÀ» ¿Ã¹Ù¸£°Ô ¼³Á¤ÇÏ°í array ¸¦ ´Ù½Ã ¸¸µå½Ê½Ã¿À. ¹°·Ð array ÀÇ µ¥ÀÌÅÍ´Â ¼Ò½ÇµË´Ï´Ù.

RAID-5 ¸¦ ±¸¼ºÇÏ´Â µð½ºÅ©¸¦ ±³Ã¼ÇÑ µÚ À籸¼ºÀÌ ½ÇÆÐÇϸé raidtabÀÇ device ¼ø¼­ ¶§¹®Àϼö ÀÖ½À´Ï´Ù. raidtabÀÇ Ã¹ ÁÙÀÇ "device ..." ¿Í "raid-disk ..." ºÎºÐÀ» array ¼ø¼­ÀÇ ¸¶Áö¸·ºÎºÐÀ¸·Î ¿Å°Ü º¸½Ã±â ¹Ù¶ø´Ï´Ù.

5. ¼º´É½ÃÇè

RAIDÀÇ °áÇÔÇã¿ë ±â´ÉÀÌ Á¤¸» ÀÛµ¿µÇ´ÂÁö, ¿©·¯ºÐÀÇ ¼³Á¤ÀÌ Àß µÇ¾ú´ÂÁö ½ÃÇèÇØ º¼ Â÷·ÊÀÔ´Ï´Ù. ±×·±µ¥ ¾î¶»°Ô µð½ºÅ©°¡ °íÀå³­ »óȲÀ» ¸ðÀÇÇÒ±î¿ä?

The short story is, that you can't, except perhaps for putting a fire axe thru the drive you want to "simulate" the fault on. You can never know what will happen if a drive dies. It may electrically take the bus it is attached to with it, rendering all drives on that bus inaccessible. I have never heard of that happening though, but it is entirely possible. The drive may also just report a read/write fault to the SCSI/IDE layer, which in turn makes the RAID layer handle this situation gracefully. This is fortunately the way things often go.

5.1 ¸ðÀÇ·Î µð½ºÅ© Àå¾Ö »óȲÀ» ¸¸µé±â

¸ðÀÇ·Î µð½ºÅ© Àå¾Ö »óȲÀ» ¸¸µé·Á¸é µð½ºÅ© Çϳª¸¦ »©½Ê½Ã¿À. ¹°·Ð ½Ã½ºÅÛÀÌ ²¨Áø »óÅ¿¡¼­ »©¾ßÇÕ´Ï´Ù. If you are interested in testing whether your data can survive with a disk less than the usual number, there is no point in being a hot-plug cowboy here. Take the system down, unplug the disk, and boot it up again.

syslog ¿Í /proc/mdstat ¸¦ ÅëÇØ RAID°¡ ¾î¶»°Ô ´ëóÇϴ°¡ º¸½Ê½Ã¿À.

µð½ºÅ© Àå¾Ö¸¦ ±Øº¹ÇÏ´Â °ÍÀº RAID-{1,4,5} ¶ó´Â °ÍÀ» ¸í½ÉÇϽʽÿÀ. Linear ³ª RAID-0 Àº ±¸¼º µð½ºÅ©°¡ ¾ø¾îÁö¸é ±×´ë·Î ³¡ÀÔ´Ï´Ù.

µð½ºÅ©¸¦ ¿¬°áÇÏ°í(¹°·Ð Àü¿øÀ» ²ö ÈÄ) raidhotadd ¸í·ÉÀ¸·Î »õ µð¹ÙÀ̽º¸¦ RAID¿¡ Ãß°¡ÇØ ÁÖ¸é µË´Ï´Ù.

5.2 ¸ðÀÇ·Î µ¥ÀÌÅÍ ¿À·ù »óȲ¸¸µé±â

RAID´Â (Çϵå¿þ¾î ¹æ½ÄÀÌµç ¼ÒÇÁÆ®¿þ¾î ¹æ½ÄÀ̵ç), µð½ºÅ©¿¡ ±â·ÏÇÑ µÚ ¿¡·¯°¡ ¸®ÅϵÇÁö ¾ÊÀ¸¸é ¹®Á¦°¡ ¾ø´Â °ÍÀ¸·Î °£ÁÖÇÏ°Ô µË´Ï´Ù. ¹°·Ð ÀÌ´Â ¹ß»ýÇÒ È®·üÀÌ ±ØÈ÷ µå¹°Áö¸¸ ÀÌ·¸°Ô µÈ´Ù¸é ÆÄÀϽýºÅÛ¿¡µµ ¿À·ù°¡ »ý±â°Ô µË´Ï´Ù.

RAID cannot and is not supposed to guard against data corruption on the media. Therefore, it doesn't make any sense either, to purposely corrupt data (using dd for example) on a disk to see how the RAID system will handle that. It is most likely (unless you corrupt the RAID superblock) that the RAID layer will never find out about the corruption, but your filesystem on the RAID device will be corrupted.

RAID´Â µ¥ÀÌÅÍ ¹«°á¼ºÀ» º¸ÀåÇÏÁö ¾Ê½À´Ï´Ù. µð½ºÅ©ÀÇ Àå¾Ö¸¦ ±Øº¹ÇÏ´Â °ÍÀÌ ÀüºÎÀÔ´Ï´Ù.

6. À籸¼º

¿©·¯ºÐ²²¼­ ÀÌ ¹®¼­ÀÇ ³ª¸ÓÁö¸¦ ÀÐÀ¸¼Ì´Ù¸é ´ëÃæ °¨ÀÌ ¿À½Ç°Ì´Ï´Ù. ¿ä¾àÇÏÀÚ¸é,

  • ½Ã½ºÅÛÀÇ Àü¿øÀ» ²û
  • Àå¾Ö°¡ ¹ß»ýÇÑ µð½ºÅ©¸¦ ±³Ã¼
  • ½Ã½ºÅÛÀÇ Àü¿øÀ» ÄÔ
  • array ¿¡ µð½ºÅ©¸¦ Ãß°¡Çϱâ À§ÇØ raidhotadd /dev/mdX /dev/sdX ¸í·ÉÀ» »ç¿ë
  • ÀÚµ¿ À籸¼ºÀÇ ÁøÇàÀ» ÁöÄѺ½
°£È¤ ÀϾ´Â ÀÏÀÌÁö¸¸ RAID ÀÇ ±¸¼º µð½ºÅ©Áß µÎ °³ ÀÌ»óÀÌ µ¿½Ã¿¡ °íÀåÀÌ ³¯ ¼öµµ ÀÖ½À´Ï´Ù. °°Àº ÄÜÆ®·Ñ·¯ ¹ö½º¿¡ Àå¾Ö°¡ ¹ß»ýÇÏ¸é ±× ¹ö½º¿¡ ¿¬°áµÈ µð½ºÅ©µé¿¡ °°ÀÌ Àå¾Ö°¡ ¹ß»ýÇÒ ¼öµµ ÀÖ´Â °ÍÀÔ´Ï´Ù. ±×·¡¼­ RAID-5 ¿¡¼­ µÎ °³ ÀÌ»óÀÇ µð½ºÅ©°¡ µ¿½Ã¿¡ °íÀåÀÌ ³ª´Â ÀÏÀº Ä¡¸íÀûÀÔ´Ï´Ù.

´ÙÀ½ÀÇ ³»¿ëÀº Martin Bene ¾¾°¡ º¸³»ÁØ ³»¿ëÀ̸ç À§¿¡ ¾ð±ÞÇÑ ³»¿ëÀÇ Àå¾Ö·Î ºÎÅÍ º¹±¸ÇÏ´Â ¹æ¹ýÀ» ¼Ò°³ÇÏ°í ÀÖ½À´Ï´Ù. ÀÌ ºÎºÐÀº /etc/raidtab ÆÄÀÏ¿¡ failed-disk Ç¥½Ã¸¦ ÇÏ´Â ¹æ¹ýÀ» ÀÌ¿ëÇÏ°í ÀÖ½À´Ï´Ù (2.2.10 ÀÌÈÄ ¹öÀüÀÇ Ä¿³Î¿¡¼­ °¡´ÉÇÑ ³»¿ëÀÔ´Ï´Ù)

6.1 ¿©·¯ °³ÀÇ µð½ºÅ© Àå¾Ö·Î ºÎÅÍÀÇ º¹±¸

»óȲÀº ÀÌ·¸½À´Ï´Ù.

  • ÄÜÆ®·Ñ·¯°¡ °íÀ峪¸é¼­ ¿¬°áµÇ¾î ÀÖ´ø µð½ºÅ© µÎ °³°¡ µ¿½Ã¿¡ offline µÉ ¶§.
  • µð½ºÅ© Çϳª°¡ °íÀ峪¼­ °°Àº ½ºÄ«½Ã ¹ö½º¿¡ ¿¬°áµÈ ¸ðµç µð½ºÅ©¿¡ Á¢±ÙÀÌ ¾È µÉ¶§.
  • ÄÉÀ̺íÀÌ ´À½¼ÇÏ°Ô ¿¬°áµÇ¾úÀ»¶§.
ÀÌ·¸°Ô µÇ¸é ¿©·¯ °³ÀÇ µð½ºÅ©¿¡¼­ µ¿½Ã¿¡ ÀϽÃÀûÀÎ °íÀåÀ» °Þ´Ù°¡ ³ªÁß¿¡´Â RAID ÀÇ superblock ÀÌ sync µÇÁö ¾Ê°Ô µÇ¾î ´õÀÌ»ó RAID ¸¦ »ç¿ëÇÒ ¼ö ¾ø°Ô µË´Ï´Ù.

ÀÌ·²¶§¿¡´Â mkraid --force ¸í·ÉÀ¸·Î RAID ÀÇ superblock À» ´Ù½Ã ¸¸µì´Ï´Ù.

À̸¦ À§Çؼ­´Â ÃÖ½ÅÀÇ /etc/raidtab À» °¡Áö°í ÀÖ¾î¾ß ÇÕ´Ï´Ù. ÆÄÀÏ¿¡ Ç¥±âµÈ ÀåÄ¡µéÀÇ ¼ø¼­¿Í ¿ø·¡ RAID ¸¦ ±¸¼ºÇÏ´Â µð½ºÅ©ÀÇ ¼ø¼­°¡ Á¤È®È÷ ÀÏÄ¡ÇÏÁö ¾ÊÀ» °æ¿ì¿¡´Â µð½ºÅ©¿¡ ÀÖ´ø µ¥ÀÌÅ͸¦ ¿ÏÀüÈ÷ ¼Ò½ÇÇÒ ¼ö ÀÖ½À´Ï´Ù.

array ¸¦ ±âµ¿ÇÒ ¶§ ±â·ÏµÇ´Â ³»¿ëÀ» syslog ¿¡¼­ È®ÀÎÇϸé, °¢ superblock ÀÇ À̺¥Æ® Ä«¿îÆ®¸¦ º¸½Ç ¼ö ÀÖ½À´Ï´Ù. º¸Åë ±× Áß °¡Àå ³·Àº ¼ýÀÚ(°¡Àå ¿À·¡µÈ °Í)¸¦ ÅÃÇÏ´Â °ÍÀÌ ÁÁ½À´Ï´Ù.

ÁÖÀÇ : failed-disk ¿É¼Ç¾øÀÌ mkraid¸¦ ½ÇÇàÇؼ­´Â ¾ÈµË´Ï´Ù.

failed-disk¿É¼ÇÀ» ÀÌ¿ëÇØ º¹±¸¸¦ ½ÃµµÇÒ ¶§¿¡´Â ¾î¶² µð½ºÅ©¸¦ È°¼ºÈ­ÇÒ °ÍÀÎÁö ¸í½ÃÇؾßÇϸç ÃÖÀûÀÇ °á°ú¸¦ À§Çؼ­´Â ¿©·¯ Á¶ÇÕÀ» ½ÃµµÇØ ºÁ¾ß ÇÒ °Ì´Ï´Ù. ÇÏÁö¸¸ À̸¦ ½ÃµµÇÒ ¶§¿¡´Â ¹Ýµå½Ã read-only ·Î ¸¶¿îÆ®ÇØ¾ß ÇÕ´Ï´Ù.

7. ¼º´É (Performance)

½ÇÁ¦·Î software RAID ¸¦ »ç¿ëÇÏ´Â ½Ã½ºÅÛ¿¡¼­ ÃøÁ¤µÈ º¥Ä¡¸¶Å· ÀڷḦ ¼Ò°³ÇÕ´Ï´Ù.

¼º´ÉÃøÁ¤Àº bonnie ¶ó´Â ÇÁ·Î±×·¥À¸·Î ¼öÇàµÇ¾úÀ¸¸ç °¢ ÃøÁ¤¿¡ »ç¿ëµÈ Àӽà ÆÄÀÏÀº ½Ã½ºÅÛ ¸Þ¸ð¸® Å©±âÀÇ µÎ ¹è ÀÌ»óÀÔ´Ï´Ù.

ÀÌ ÀÚ·á´Â ÇϳªÀÇ Å« ÆÄÀÏÀÇ ÀÔ/Ãâ·Â ´ë¿ªÆø¸¸À» ÃøÁ¤ÇÑ °ÍÀÔ´Ï´Ù. ´ë¿ë·®ÀÇ Àбâ/¾²±â¿¡¼­ÀÇ I/O ´ë¿ªÆø ÃÖ´ëÄ¡¿¡ °üÁ¡À» µÐ´Ù¸é ÀÌ ÀÚ·áµéÀº À¯¿ëÇÏ°Ô ¾²ÀÏ ¼ö ÀÖ½À´Ï´Ù. ÇÏÁö¸¸ ´º½º±×·ì ¼­¹ö³ª À¥ ¼­¹ö µîÀ» ¿ëµµ·Î ÇÏ´Â ½Ã½ºÅÛ¿¡¼­´Â Å« Àǹ̰¡ ¾øÀ» ¼öµµ ÀÖ½À´Ï´Ù. ÀÌ ÀÚ·á´Â ¾îµð±îÁö³ª ¸ðÀÇ·Î ½ÇÇèµÈ °ÍÀÔ´Ï´Ù. ±×·¯¹Ç·Î Âü°í¸¸ ÇϽñ⠹ٶø´Ï´Ù.

¼º´É ÃøÁ¤¿¡ »ç¿ëµÈ ½Ã½ºÅÛÀÇ »ç¾çÀº ´ÙÀ½°ú °°½À´Ï´Ù.

  • Dual Pentium Pro 150 MHz
  • 256 MB RAM (60 MHz EDO)
  • Three IBM UltraStar 9ES 4.5 GB, SCSI U2W
  • Adaptec 2940U2W
  • One IBM UltraStar 9ES 4.5 GB, SCSI UW
  • Adaptec 2940 UW
  • Kernel 2.2.7 with RAID patches

U2W ÄÜÆ®·Ñ·¯¿¡ ¼¼ °³ÀÇ U2W µð½ºÅ©°¡ ¿¬°áµÇ¾îÀÖ°í, UW ÄÜÆ®·Ñ·¯¿¡ UW µð½ºÅ© Çϳª°¡ ¿¬°áµÇ¾îÀÖ½À´Ï´Ù.

RAID ÀÇ »ç¿ë¿©ºÎ¸¦ ¶°³ª¼­ ÀÌ »ç¾çÀÇ ½Ã½ºÅÛ¿¡¼­ SCSI ¹ö½º¸¦ ÅëÇØ 30 MB/s ÀÌ»óÀÇ ´ë¿ªÆøÀ» ¾òÀ» ¼ö ¾ø¾ú½À´Ï´Ù. ÀÌ´Â ÀÌ ½Ã½ºÅÛÀÌ ±¸ÇüÀε¥´Ù°¡ ¸Þ¸ð¸®ÀÇ ´ë¿ªÆøÀÌ ³·±â ¶§¹®À̾ú´ø°Í °°½À´Ï´Ù.

7.1 RAID-0

Àбâ´Â ¿¬¼ÓµÈ ºí·ÏµéÀÇ ÀÔ·ÂÀ̸ç, ¾²±â´Â ¿¬¼ÓµÈ ºí·ÏµéÀÇ Ãâ·ÂÀÔ´Ï´Ù. ÃøÁ¤¿¡ »ç¿ëµÈ ÆÄÀÏÀÇ Å©±â´Â 1GB À̸ç single-user ¸ðµå¿¡¼­ ¼öÇàµÇ¾ú½À´Ï´Ù. TCQ ±â´ÉÀº »ç¿ëÇÏÁö ¾Ê¾Ò½À´Ï´Ù.


Chunk size Block size Read kB/s Write kB/s
4k 1k 19712 18035
4k 4k 34048 27061
8k 1k 19301 18091
8k 4k 33920 27118
16k 1k 19330 18179
16k 2k 28161 23682
16k 4k 33990 27229
32k 1k 19251 18194
32k 4k 34071 26976

RAID ÀÇ chunk-size ´Â º° ¿µÇâÀÌ ¾ø¾îº¸ÀÔ´Ï´Ù. ÇÏÁö¸¸ IA-32 ½Ã½ºÅÛ¿¡¼­ ext2fs ÀÇ block-size ´Â 4kB(page size)¸¦ À¯ÁöÇÏ´Â °ÍÀÌ ÁÁ½À´Ï´Ù.

7.2 TCQ ¸¦ Àû¿ëÇÑ RAID-0

À̹ø¿¡´Â SCSI µå¶óÀ̹ö¿¡ Å©±â 8ÀÇ queue depth TCQ ¸¦ Àû¿ëÇÏ¿´½À´Ï´Ù. º° Â÷ÀÌ°¡ ¾ø¾ú½À´Ï´Ù.


Chunk size Block size Read kB/s Write kB/s
32k 4k 33617 27215

TCQ °¡ ¾à°£ÀÇ ¾²±â ¼º´ÉÀ» Çâ»ó½ÃÄ×À¸³ª ÀüüÀûÀ¸·Î´Â Å« Â÷ÀÌ°¡ ¾ø¾ú½À´Ï´Ù.

7.3 RAID-5

RAID-5 ¿¡¼­ °°Àº ÃøÁ¤À» ÇÏ¿´½À´Ï´Ù.


Chunk size Block size Read kB/s Write kB/s
8k 1k 11090 6874
8k 4k 13474 12229
32k 1k 11442 8291
32k 2k 16089 10926
32k 4k 18724 12627

À̹ø¿¡´Â chunk-size ¿Í block-size ÀÇ Â÷ÀÌ¿¡ µû¶ó ´Ù¸¥ °á°ú°¡ ³ª¿Ô½À´Ï´Ù.

7.4 RAID-10

RAID-10 Àº mirrored stripes ·Î½á, µÎ °³ÀÇ RAID-0 ·Î RAID-1 ¸¦ ±¸ÇöÇÑ °ÍÀÔ´Ï´Ù. RAID-10 is ``mirrored stripes'', or, a RAID-1 array of two RAID-0 arrays. chunk-size ´Â RAID-1 °ú RAID-0 array ¸ðµÎ °°°Ô ¼³Á¤Çß½À´Ï´Ù. ¼­·Î ´Ù¸¥ Å©±âÀÇ chunk-size µµ °¡´ÉÇÏÁö¸¸ ÃøÁ¤Çغ¸Áö ¾Ê¾Ò½À´Ï´Ù.


Chunk size Block size Read kB/s Write kB/s
32k 1k 13753 11580
32k 4k 23432 22249

ÃøÁ¤¿¡ »ç¿ëµÈ ÆÄÀÏÀÇ Å©±â´Â 900MB ¿´À¸¸ç ³× °³ÀÇ 500MB ÆÄƼ¼ÇÀ¸·Î ±¸¼ºµÇ¾î °ø°£ÀÌ ÃæºÐÇÏÁö ¸øÇÑ °ü°è(µÎ °³ÀÇ 1000MB array ·Î µÈ »óȲ)·Î 1GB ÆÄÀÏÀ» »ç¿ëÇÒ ¼ö °¡ ¾ø¾ú½À´Ï´Ù.

8. °ü·Ã ÇÁ·Î±×·¥

ÀÌ ¹®¼­¿¡´Â ¾øÁö¸¸ Software-RAID À» ¿î¿µÇϴµ¥ À¯¿ëÇÑ ÇÁ·Î±×·¥µéÀÌ °³¹ßÁßÀ̰ųª °³¹ßµÇ¾î ÀÖÀ» °ÍÀÔ´Ï´Ù.

8.1 mdadm : raidtools¸¦ º¸Á¶Çϰųª ´ëüÇÒ ¼ö ÀÖ´Â ÇÁ·Î±×·¥

Neil Brown°¡ ¸¸µç mdadm´Â http://www.cse.unsw.edu.au/~neilb/source/mdadm/ ¿¡¼­ ±¸ÇÒ ¼ö ÀÖ½À´Ï´Ù. ÀÌ ÇÁ·Î±×·¥Àº RAID ½Ã½ºÅÛÀ» ¿î¿µÇϴµ¥ ´ë´ÜÈ÷ À¯¿ëÇϸç raidtools°ú ÇÔ²², ȤÀº ´ëüÇؼ­ ¾µ ¼ö ÀÖÀ» Á¤µµÀÔ´Ï´Ù.

8.2 RAID ÀÇ Å©±â Á¶Á¤°ú º¯È¯

ÇöÀç ±¸¼ºµÇ¾î ÀÖ´Â RAID array ¿¡ ´Ù¸¥ µð½ºÅ©¸¦ Ãß°¡Çϱâ´Â ½±Áö ¾Ê½À´Ï´Ù. À̸¦ °¡´ÉÄÉ ÇÏ´Â ÇÁ·Î±×·¥ÀÌ °³¹ßµÇ¾úÀ¸¸ç http://unthought.net/raidreconf ¿¡¼­ ±¸ÇÒ ¼ö ÀÖ½À´Ï´Ù. ±× ÇÁ·Î±×·¥À¸·Î RAID ·¹º§À» ÀüȯÇÒ ¼ö ÀÖÀ¸¸ç(¿¹: µÎ °³ÀÇ RAID-1 array ¸¦ ³× °³ÀÇ RAID-5 array ·Î º¯È¯ÀÌ °¡´É) chunk-size Á¶ÀýÀ̳ª µð½ºÅ© Ãß°¡ µîÀÇ ÀÛ¾÷À» ÇÒ ¼ö ÀÖ½À´Ï´Ù.

ÀÌ ÇÁ·Î±×·¥Àº ¾ÆÁ÷ ¿Ïº®ÇÏÁö ¾ÊÀ¸¹Ç·Î µð½ºÅ©ÀÇ ¸ðµç µ¥ÀÌÅ͸¦ ÀÒÀ» ¼öµµ ÀÖ½À´Ï´Ù. ±×·¯¹Ç·Î ÀÌ ÇÁ·Î±×·¥À» »ç¿ëÇϱâ Àü¿¡ ¹Ýµå½Ã ¹é¾÷À» ÇØ µÎ¾î¾ß ÇÕ´Ï´Ù.

8.3 ¹é¾÷

RAID ´Â ¹é¾÷ÀÇ ´ë¾ÈÀÌ µÉ ¼ö ¾ø´Ù´Â °ÍÀ» ¸í½ÉÇϽʽÿÀ. RAID ÀÇ µ¥ÀÌÅÍ ÀÌÁßÈ­°¡ ÀÏÁÖÀÏ ÀüÀ̳ª ÇÑ ´Þ ÀüÀÇ µ¥ÀÌÅ͸¦ º¸Á¸ÇØ Áشٰųª È­Àç, ÁöÁø µîÀÇ ÃµÀçÁöº¯À¸·ÎºÎÅÍ µ¥ÀÌÅ͸¦ º¸Á¸ÇØ ÁÖÁø ¸øÇÑ´Ù´Â °ÍÀÔ´Ï´Ù.

RAID ¸¦ »ç¿ëÇÏ¿©µµ ÁÖ±âÀûÀÎ ¹é¾÷Àº ÇʼöÀÔ´Ï´Ù. ÁÁÀº ¹é¾÷Åø·Î´Â Amanda °¡ ÀÖ½À´Ï´Ù.

9. °¨»çÀÇ ±Û

ÀÌ ¹®¼­¸¦ ¸¸µå´Âµ¥ µµ¿òÀ» ÁֽŠºÐµéÀÔ´Ï´Ù.

  • Mark Price and IBM
  • Michael,
  • Damon Hoggett
  • Ingo Molnar
  • Jim Warren
  • Louis Mandelstam
  • Allan Noah
  • Yasunori Taniike
  • Martin Bene
  • Bennett Todd
  • The Linux-RAID mailing list people
  • The ones I forgot, sorry :)

ÀÌ ¹®¼­ÀÇ ¹ßÀüÀ» À§ÇØ °íÃÄ¾ß ÇÒ °ÍµéÀ̳ª °ÇÀÇ»çÇ×À» ÀúÀÚ¿¡°Ô º¸³»Áֽñ⠹ٶø´Ï´Ù.




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