AS/400中磁盘保护的类型

居士

DISK PROTECTION

  MIRRORED SYSTEM DISK LEVEL PROTECTION (#0040):  Causes the order to
  fail if sufficient disk units are not ordered to support DEVICE-LEVEL
  mirrored protection.  On upgrade orders, a warning message will be
  generated during installation of the upgrade if sufficient disk units
  are not available.  #0040 requires all disk units

  to be placed into mirrored pairs.  The load source must be controlled
  by the first disk controller and must be mirrored to a like disk unit
  also attached to the first disk controller.  Minimum number of disks
  allowed on a system:  two.

  DEVICE PARITY PROTECTION-ALL (#0041):  Causes the order to fail if a
  non-RAID configuration is ordered.  This is the default specify code
  for data protection.  #0041 requires all internal disk units be placed
  into RAID arrays using a RAID capable disk controller.  The rules for
  RAID can be found in the disk controller descriptions.  All external
  disk units must be RAID capable.

  MIRRORED SYSTEM IOP LEVEL PROTECTION (#0042):  Causes the order to
  fail if sufficient disk units and IOPs are not included on the order
  to support IOP-LEVEL mirrored protection.  On Upgrade orders, a
  warning message will be generated during installation of the upgrade
  if sufficient Disk units and IOPs are not available.  #0042 requires
  all disk units to be placed into mirrored pairs.  Each mirrored pair
  of disk units must be on separate disk unit IOP.  The load source must
  be controlled by the first disk controller and must be mirrored to a
  like disk unit also attached to the first disk controller.  (#0040
  protection).  Minimum number of disks allowed on a system:  four.

  MIRRORED SYSTEM BUS LEVEL PROTECTION (#0043):  Causes the order to
  fail if sufficient disk units, IOPs, and expansion units are not
  included on the order to support BUS-LEVEL mirrored protection.  On
  upgrade orders, a warning message will be generated during
  installation of the upgrade if sufficient disk units, IOPs, and
  expansion units are not available.

  #0043 requires all disk units to be placed into mirrored pairs.  Each
  mirrored pair of disk units must be on separate busses.  The load
  source must be controlled by the first disk controller and must be
  mirrored to a like disk unit also attached to the first disk
  controller.  (#0040 protection).  Minimum number of disks allowed on a
  system:  four.

居士

我们用的最多的就是0041这种保护方式，也就是RAID-5,有谁用过别的，大家讨论谈论。

居士

在新问世的800，810，825，870，890中，可以通过3块硬盘在硬件层实现RAID-5,具体的技术资料我还没有拿到，谁有，可以在这里共享。

zli

我装过的机子，主要用raid,但是书上是叫parity，一定要四快硬盘以上才能做，而且是要偶数个硬盘，这是一种硬件方式的保护，在坏一快硬盘时有用。要一快raid卡
另一种是mirror保护，是软件保护，我做过，觉的不好

居士

RAID-5  并没有规定偶数个硬盘，我经常使用奇数个硬盘。另外，现在最新的技术，最少3块硬盘就可以做RAID-5了。

对于400的mirror保护，使用的是SCSI卡来实现的，可惜我没有做过。

zli

0041 和rAID 5还是有区别的

居士

具体说说看。我们可以讨论讨论。