Dell PowerVault MD3200 Owner's Manual - Page 43

Virtual Disk Operations Limit 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. 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. Planning: MD3200 Series Storage Array Terms and Concepts 43