•
The pre-read consistency check for a thin virtual disk cannot be enabled.
•
A thin virtual disk cannot serve as the target virtual disk in a Virtual Disk Copy.
•
A thin virtual disk cannot be used in a Remote Replication (Legacy) operation.
Thin virtual disk attributes
When you create a thin virtual disk from free capacity in an existing disk pool, you can manually set disk attributes or allow MD Storage
Manager to assign default attributes. The following manual attributes are available:
•
Preferred Capacity
— Sets the initial physical capacity of the virtual disk (MB, GB or TB). Preferred capacity in a disk pool is allocated
in 4 GB increments. If you specify a capacity amount that is not a multiple of 4 GB, MD Storage Manager assigns a 4 GB multiple and
assigns the remainder as unused. If space exists that is not a 4 GB multiple, you can use it to increase the size of the thin virtual disk. To
increase the size of the thin virtual disk, select
Storage
>
Virtual Disk
>
Increase Capacity.
•
Repository Expansion Policy
— Select either
Automatic
or
Manual
to indicate whether MD Storage Manager must automatically
expand physical capacity thresholds. If you select
Automatic
, enter a
Maximum Expansion Capacity
value that triggers automatic
capacity expansion. The MD Storage Manager expands the preferred capacity in increments of 4 GB until it reaches the specified
capacity. If you select
Manual
, automatic expansion does not occur and an alert is displayed when the
Warning Threshold
value
percentage is reached.
•
Warning Threshold
— When consumed capacity reaches the specified percentage, MD Storage Manager sends an E-mail or SNMP
alert.
Thin virtual disk states
The following are the virtual disk states displayed in MD Storage Manager:
•
Optimal
— Virtual disk is operating normally.
•
Full
— Physical capacity of a thin virtual disk is full and no more host write requests can be processed.
•
Over Threshold
— Physical capacity of a thin virtual disk is at or beyond the specified
Warning Threshold
percentage. The storage
array status is shown as
Needs Attention
.
•
Failed
— Virtual disk failed, and is no longer available for read or write operations. The storage array status is shown as
Needs
Attention
.
Comparison—Types of virtual disks and copy services
The availability of copy services depends on the type of virtual disk that you are working with.
Table 9. Copy services features supported on each type of virtual disk
Copy Services Feature
Standard Virtual Disk in a Disk Group
Standard Virtual Disk in a Disk
Pool
Thin Virtual Disk
Snapshot image
Supported
Supported
Supported
Snapshot virtual disk
Supported
Supported
Supported
Rollback of snapshot
Supported
Supported
Supported
Delete virtual disk with
snapshot images or snapshot
virtual disks
Supported
Supported
Supported
Consistency group
membership
Supported
Supported
Supported
Remote Replication (Legacy)
Supported
Not supported
Not supported
70
Disk groups, standard virtual disks, and thin virtual disks