HP Surestore Disk Array FC60 HP SureStore E Disk Array FC60 Service Manual (A5 - Page 52
Volume Group,
View all HP Surestore Disk Array FC60 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 52 highlights
disk. The rebuilt volume group contains an exact replica of the information it would have contained had the disk not failed. Until a failed disk is replaced (or a rebuild on a global hot spare is completed), the volume group operates in degraded mode. The volume group must now use the data and parity on the remaining disks to recreate the content of the failed disk, which reduces performance. In addition, while in degraded mode, the volume group is susceptible to the failure of the second disk. If a second disk in the volume group fails while in degraded mode, parity can no longer be used and all data on the volume group becomes inaccessible. Figure 21 illustrates the distribution of user and parity data in a five-disk RAID 3 volume group. The the stripe segment size is 8 blocks, and the stripe size is 40 blocks (8 blocks times 5 disks). The disk block addresses in the stripe proceed sequentially from the first disk to the second, third, and fourth, then back to the first, and so on. Figure 21 RAID 3 Volume Group 52 Disk Array High Availability Features