Dell PowerVault MD3000i - Manual (Page 35)

Using Your RAID Enclosure
35
Other conditions under which sectors are added to the unreadable sector log
include:
• A media error is encountered when trying to access a physical disk that is a
member of a nonredundant disk group (RAID 0 or degraded RAID 1,
RAID 5 or RAID 10).
• An error is encountered on source disks during rebuild.
NOTE:
Data on an unreadable sector is no longer accessible.
RAID Operations and Features
This section details the following RAID operations and features supported by
your enclosure or RAID controller:
• Virtual disk operations
• Disk group operations
• RAID background operations priority
• Virtual disk migration and roaming
Virtual Disk Operations
Virtual Disk Initialization
Every virtual disk must be initialized. Up to four concurrent initializations
can occur for the same RAID controller module.
Background Initialization
The RAID controller module executes a background initialization when the
virtual disk is created to establish parity, while allowing full host server access
to the virtual disks. Background initialization does not run on RAID 0 virtual
disks.
The background initialization rate is controlled by MD Storage Manager. You
must stop an ongoing background initialization before you change the rate, or
the rate change will not take effect. After you stop background initialization
and change the rate, the rate change will take effect when the background
initialization restarts automatically.
NOTE:
Unlike initialization of virtual disks, background initialization does not clear
data from the physical disks.