Dell MD3200i, MD3220i Disk Group Operations

Planning: MD3200i Series Storage Array Terms and Concepts 45

• 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

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 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:

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