HP NetRAID-4M Configuration and Upgrade Guide (Release 5)

Chapter 10 Glossary
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Partitions - System vs. Boot
Microsoft uses the term “system partition” to refer to the partition that contains the
boot files such as NTLDR, and the term “boot partition” to refer to the volume
containing the Windows NT 4.0 operating system files. This terminology is reversed
from general industry usage.
RAID bad block replacement (BBR)
A process automatically invoked when a controller cannot read or write to the
media. BBR attempts the write three times to the same block. If that process fails,
RAID controller asks the drive to mark that block bad and to allocate another block.
If the entire BBR process exceeds 3 minutes the drive is marked as bad and taken
offline. This forces the user to take action (replace the drive).
RAID background consistency check (BCC)
BCC is a process for testing readability of the blocks on physical drives within
boundaries of an entire container. BCC does not touch un-initialized drives, spare
drives, and free space. BCC is a low priority task that runs in the background of other
tasks so as not to inhibit performance. BCC issues 80 block SCSI verify commands
(no data transfer on the SCSI bus) to each container member every second. BCC
does not validate stripe parity, nor does it repair anything. However, if background
consistency check (SCSI verify command) provokes any drive errors such as media
errors, 04 hardware errors, or SMART errors, this information is then managed by
the SCSI layer that would then initiate the bad block recovery (BBR) process for
corrective action, and this could lead to, for example, event log errors and drives
being declared dead.
RAID consistency check
A manually invoked scrubbing process on RAID1 and RAID5. Like scrubbing, it
validates both the data and parity integrity in your containers. Use the Consistency
Check command at any time to read all the blocks of a mirror set or a multilevel
container of mirror sets. It is important to run this task after a system failure to see
if the blocks are consistent. If Consistency Check detects any inconsistent blocks, it
can fix them. Consistency Check operates from the container menu. To repair any
errors encountered, set the "repair" check box in the Container Consistency Check
dialog box.