Storage Controller Features 31Reconfiguring Virtual DisksAn online virtual disk can be reconfigured in ways that expands its capacityand/or change its RAID level. Spanned virtual disks such as RAID 10, 50, and60 cannot be reconfigured.Online Capacity Expansion (OCE) can be done in two ways. The first way isto expand the volume using free space already in the disk group. For example,if there is a single virtual disk in a disk group and free space is available, thevirtual disk’s capacity can be expanded within that free space. If a virtual diskis created and it does not use the maximum size of the disk group, free spaceis available and OCE is possible. Free space is also available when a diskgroup’s physical disks are replaced by larger disks using the Replace Memberfeature. The second method by which OCE can be done is by adding physicaldisks to the disk group and using OCE to incorporate free space from thenewly added disks into the virtual disk.RAID Level Migration (RLM) refers to changing a virtual disk’s RAID level.Both RLM and OCE can be done at the same time so that a virtual disk cansimultaneously have its RAID level changed and its capacity increased. Whena RLM/OCE operation is complete, a reboot is not required.For a list ofRLM/OCE possibilities, see Table 3-2. The source RAID level columnindicates the virtual disk RAID level before the RLM/OCE and the targetRAID level column indicates the RAID level after the operation hascompleted.NOTE: If you configure 64 virtual disks on a controller, you cannot perform aRAID level migration or capacity expansion on any virtual disk.NOTE: The controller changes the write cache policy of all virtual disks undergoinga RLM/OCE to Write-Through until the RLM/OCE is complete.
