Disk Group Operations; Raid Level Migration; Segment Size Migration - Dell PowerVault MD3200i Owner's Manual

• Foreground initialization
• Consistency check
• Rebuild
• Copy back.
If a redundant RAID controller module fails with existing virtual disk
processes, the processes on the failed controller are transferred to the peer
controller. A transferred process is placed in a suspended state if there are
four active processes on the peer controller. The suspended processes are
resumed on the peer controller when the number of active processes falls
below four.

Disk Group Operations

RAID Level Migration

You can migrate from one RAID level to another depending on your
requirements. For example, fault-tolerant characteristics can be added to a
stripe set (RAID 0) by converting it to a RAID 5 set. MDSM provides
information about RAID attributes to assist you in selecting the appropriate
RAID level. You can perform a RAID level migration while the system is still
running and without rebooting, which maintains data availability.

Segment Size Migration

Segment size refers to the amount of data (in kilobytes) that the storage array
writes on a single physical disk in a virtual disk before writing data on the next
physical disk. Valid values for the segment size are 8, 16, 32, 64, 128, 256, and
512 KB.
Dynamic segment size migration enables the segment size of a given virtual
disk to be changed. A default segment size is set when the virtual disk is
created, based on such factors as the RAID level and expected usage. You can
change the default value if segment size usage does not match your needs.
When considering a segment-size change, two scenarios illustrate different
approaches to the limitations:
Planning: MD3200i Series Storage Array Terms and Concepts
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