Specifications

SCSI to SATA RAID Subsystem | Administrator’s Manual Terminal Operation | en 111
Bosch Security Systems F.01U.027.802 | V1 | 2006.11
7.9.8 Media Scan
Media Scan examines drives and detects the presence of bad blocks. If any data blocks have
not been properly committed and are found during the scanning process, data from those
blocks are automatically recalculated, retrieved and stored onto undamaged sectors. If bad
blocks are encountered on yet another drive during the rebuild process, the block LBA (Logi-
cal Block Address) of those bad blocks will be shown. If rebuild is carried out under this situa-
tion, rebuild will continue with the unaffected sectors, salvaging the majority of the stored
data.
Fig. 7.39 Media Scan Screen
There are two options with performing the Media Scan:
1. Media Scan Priority: determines how much of the system resources will be used for the
drive scanning and recalculating process.
2. Iteration Count: determines how many times the scan is performed. If set to “continu-
ous,” the scan will run in the background continuously until it is stopped by a user.
The system can automatically perform a Media Scan according to a preset task schedule. For
more details, please refer to Section 10 Data Integrity.
7.9.9 Write Policy
Fig. 7.40 Write Policy Screen
The Write-back cache setting can be configured differently on each array. Setting to the
default value means the array setting is coordinated with the controller’s general setting. The
controller’s general setting option can be found in “View and Edit Configuration Parameters” -
> “Caching Parameters” -> “Write-Back Cache.” Note that cached writes are lost if a power
failure occurs.