Multi-Tiered Storage
120
Titan SiliconServer
Performing a Consistency Check on a System Drive
A typical file system is a mixture of frequently used files, rarely used files, and free space. If a
disk develops bad spots in sectors that are not often accessed, this failure could remain
undetected. To prevent a disk failure during a rebuild, which could lead to data loss, it is
necessary to detect unreliable disks promptly, thus preventing the RAID controller from failing
them at a critical time.
It is possible to instruct a RAID controller to check, and optionally repair, the parity on any
System Drive (SD) configured in RAID 1/5/10 (that is, any SD that can survive the failure of a
single disk). The parity or mirrored data is used to rebuild the SD in the event of a disk failure.
Note:
A RAID consistency check and a file system check are two distinct
operations. The first checks, and optionally repairs, the RAID parity in a
System Drive. However, it does not check the integrity of file system. That
task is performed by a file system check.
It is possible to start a consistency check at any time from Web Manager or using the command
line interface (CLI). It is not necessary to take the SD offline to run a consistency check.
However, on each RAID rack, only one SD can be checked or rebuilt at a time. The performance
of the host RAID controllers diminishes until the process ends. Other RAID racks are not
affected.
To run a consistency check on a System Drive
1.
From the
Storage Management
page, click
System Drives.
2.
Click
details
next to the System Drive on which to run the consistency check.
3.
Click
Start Consistency Check
.
4.
To start the consistency check, click
yes
to begin a check in which detected faults will be
fixed. Click
no
to skip the repair of faults found. Click
cancel
to return to the
System
Drive Details
page.
Note:
If a RAID controller is replaced, the new RAID controller only becomes
effective when the surviving RAID controller has completed a consistency
check of all redundant System Drives.
During the consistency check, if parity errors are found, they will be logged in Titan’s Event Log.
If a check was initiated with fault correction enabled, the parity will be updated to match the