Dell PowerVault MD3220 - Manual (Page 136)

136 Configuration: Disk Groups and Virtual Disks
Storage Array Media Scan
The media scan is a background operation that examines virtual disks to
verify that data is accessible. The process finds media errors before normal
read and write activity is disrupted and reports errors to the event log.
NOTE: You cannot enable background media scans on a virtual disk comprised of
Solid State Disks (SSDs).
Errors discovered by the media scan include:
• Unrecovered media error—Data could not be read on the first attempt or
on any subsequent attempts. For virtual disks with redundancy protection,
data is reconstructed, rewritten to the physical disk, and verified and the
error is reported to the event log. For virtual disks without redundancy
protection (RAID level 1, RAID level 5, and RAID level 6 virtual disks), the
error is not corrected but is reported to the event log.
• Recovered media error—Data could not be read by the physical disk on the
first attempt but was successfully read on a subsequent attempt. Data is
rewritten to the physical disk and verified and the error is reported to the
event log.
• Redundancy mismatches error—The first 10 redundancy mismatches that
are found on the virtual disk are reported to the event log.
• Unfixable error—Data could not be read and parity or redundancy
information could not be used to regenerate the data. For example,
redundancy information cannot be used to reconstruct the data on a
degraded virtual disk. The error is reported to the event log.
For more information, see the PowerVault Modular Disk Storage Manager
online help topics.
Changing Media Scan Settings
To change the media scan settings:
1 In the AMW, select the Logical tab and select any virtual disk.
2 Select Virtual Disk Change Media Scan Settings.
The Change Media Scan Settings window is displayed.
3 Deselect Suspend media scan if selected.
4 In Scan duration, enter or select the duration (in days) for the media scan.
book.book Page 136 Tuesday, June 18, 2013 2:53 PM