DELL MD3220 사용자 설명서

Planning: MD3200 Series Storage Array Terms and Concepts

The maximum number of active, concurrent virtual disk processes per RAID 

controller module installed in the storage array is four. This limit is applied to 

the following virtual disk processes: 

• Background initialization
• 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.

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. 

book.book  Page 43  Monday, June 21, 2010  11:00 AM