Filter
Top Products
40 Planning: MD3200 Series Storage Array Terms and Concepts
3
Provide host server access.
4
Create mappings to associate the virtual disks with the host servers.
NOTE: Host server access must be created before mapping virtual disks.
Disk groups are always created in the unconfigured capacity of a storage array.
Unconfigured capacity is the available physical disk space not already
assigned in the storage array.
Virtual disks are created within the free capacity of a disk group. Free capacity
is the space in a disk group that has not been assigned to a virtual disk.
Virtual Disk States
The storage array recognizes the following virtual disk states.
RAID Levels
RAID levels determine the way in which data is written to physical disks.
Different RAID levels provide different levels of accessibility, redundancy, and
capacity.
Table 4-2. RAID Controller Virtual Disk States
State Description
Optimal The virtual disk contains physical disks that are all online.
Degraded The virtual disk with a redundant RAID level contains an inaccessible
physical disk. The system can still work properly, but performance may
be affected and additional disk failures may result in data loss.
Offline A virtual disk with one or more member disks is in an inaccessible
(failed, missing, or offline) state. Data on the virtual disk is no longer
accessible.
Force online The storage array forces a virtual disk that is in an Offline state to an
Optimal state. If all the member physical disks are not available, the
storage array forces the virtual disk to a Degraded state. The storage
array can force a virtual disk to an Online state only when a sufficient
number of physical disks are available to support the virtual disk.
book.book Page 40 Tuesday, September 27, 2011 3:25 PM