Disk groups, standard virtual disks, and thin
virtual disks
Creating disk groups and virtual disks
Disk groups are created in the unconfigured capacity of a storage array, and virtual disks are created in the free capacity of a disk group or
disk pool. The maximum number of physical disks supported in a disk group is 120 (180 with the premium feature activated). The hosts
attached to the storage array read and write data to the virtual disks.
NOTE:
Before you can create virtual disks, you must first organize the physical disks into disk groups and configure host access.
Then you can create virtual disks within a disk group.
To create a virtual disk, use one of the following methods:
•
Create a disk group from unconfigured capacity. First define the RAID level and free capacity (available storage space) for the disk
group, and then define the parameters for the first virtual disk in the new disk group.
•
Create a new virtual disk in the free capacity of an existing disk group or disk pool. You only need to specify the parameters for the new
virtual disk.
A disk group has a set amount of free capacity that is configured when the disk group is created. You can use that free capacity to
subdivide the disk group into one or more virtual disks.
You can create disk groups and virtual disks using:
•
Automatic configuration—Provides the fastest method, but with limited configuration options
•
Manual configuration—Provides more configuration options
When creating a virtual disk, consider the uses for that virtual disk, and select an appropriate capacity for those uses. For example, if a disk
group has a virtual disk that stores multimedia files (which tend to be large) and another virtual disk that stores text files (which tend to be
small), the multimedia file virtual disk requires more capacity than the text file virtual disk.
A disk group should be organized according to its related tasks and subtasks. For example, if you create a disk group for the Accounting
Department, you can create virtual disks that match the different types of accounting performed in the department: Accounts Receivable
(AR), Accounts Payable (AP), internal billing, and so forth. In this scenario, the AR and AP virtual disks probably need more capacity than
the internal billing virtual disk.
NOTE:
In Linux, the host must be rebooted after deleting virtual disks to reset the /dev entries.
NOTE:
Before you can use a virtual disk, you must register the disk with the host systems. See
Creating disk groups
NOTE:
If you have not created disk groups for a storage array, the Disk Pool Automatic Configuration Wizard is displayed when
you open the AMW. For more information about creating storage space from disk pools, see
NOTE:
Thin-provisioned virtual disks can be created from disk pools. If you are not using disk pools, only standard virtual disks
can be created. For more information, see
You can create disk groups either using
Automatic
configuration or
Manual
configuration.
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Disk groups, standard virtual disks, and thin virtual disks
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