Use the Recover VDisk panel in
the SAN Volume Controller Console to
recover virtual disks (VDisks) that have lost cached data or space-efficient
metadata, usually as a result of hardware failure. A Fast Write State
of Corrupt indicates this data loss.
Introduction
The specified VDisk or copies
are recovered and brought back online during the recovery process.
If a VDisk is space-efficient or has space-efficient copies, its status
is set to Repairing and is not brought back
online until the repair process completes. If the VDisk is mirrored,
this action completes resynchronization of the copy from a synchronized
copy.
You might also use
this action to recover VDisk copies where one copy is offline and
corrupted and the other copy is online and not corrupted. The VDisk
displays as online and not corrupted. The recovery process resynchronizes
the offline and corrupt copy with the synchronized VDisk copy and
brings the copy back online. To view the status of VDisk copies, click
the VDisk name and select Copies to display
details on the copies that are associated with the selected VDisk.
Attributes
The
following attributes are displayed in the table:
- Name
- Displays the name of the VDisk.
- State
- Displays the state of the VDisk. The following values are possible:
- Offline
- Indicates that the VDisk is unavailable. One or more of the managed
disks (MDisks) that make up the VDisk are degraded or offline and
consequently the VDisk is unavailable.
- Online
- Indicates that the VDisk is available. All the MDisks that make
up the VDisk are available.
- Degraded
- Indicates that the status of the VDisk is degraded. A VDisk is
degraded if the VDisk is online to one node and offline to the other
node or if the VDisk is online to one node and the other node is missing.
The status of a VDisk is online if the MDisk group that is presenting
the VDisk is online.
- Fast Write State
- Indicates if the VDisk has data in the cache. The value of this
option can help determine whether any recovery action is necessary
for VDisks.
- Empty
- Indicates that the VDisk does not have outstanding data in the
cache. This indicates that the data has not been corrupted and does
not need any recovery action.
- Not Empty
- Indicates that the VDisk has unwritten data in the cache.
- Corrupt
- Indicates that the VDisk has lost cache data or space-efficient
directory metadata, usually as the result of the I/O group going offline.
To recover this lost data, you can use Recover VDisks or Recover All
Corrupted VDisks from the task list on this panel to restore the lost
data and bring the VDisk back online.
- Repairing
- Indicates that the VDisk is space-efficient or has space-efficient
copies and is being held offline while its metadata is repaired. This
state follows from one of the VDisk recovery tasks.
- I/O Group
- Displays the name of the I/O group that contains this VDisk. You
can use the Recover VDisks, Recover All Corrupted VDisks, or Recover
VDisks by I/O Group panels to recover a VDisk and bring it back online.
- MDisk Group
- Displays the name of the MDisk group that contains this VDisk.
The
value Many indicates that this VDisk has multiple
copies, which can be on different MDisks. Click the link in this field
to display the View VDisk Copy Details panel
for more details on the MDisk that is used by each of the VDisk copies.
- Capacity (MB)
- Displays the size of the VDisk in megabytes.
- Type
- Displays the VDisk type. The following values are possible:
- Striped
- Indicates that the VDisk was created from multiple MDisks that
are in the MDisk group. Extents are allocated on the MDisks in the
specified order.
- Sequential
- Indicates that the VDisk was created from one MDisk that is in
the MDisk group. Extents are sequentially allocated on the MDisk.
- Image
- Indicates that the VDisk was created from one MDisk that is in
the MDisk group. Provides a direct block-for-block translation from
the MDisk to the VDisk. This is intended for MDisks that already contain
data that was not written through the SAN Volume Controller.
- Many
- Indicates that the VDisk has multiple copies, which can have different
types. Click the link to determine the type for each of the VDisk
copies.
- Hosts
- Displays if the selected VDisk is mapped to the host. The possible
values are:
- Mapped
- Indicates that the VDisk is mapped to a host.
- –
- Indicates that the VDisk is not mapped to a host.
- FC Pair
- Displays the name of the FlashCopy® mapping that this
VDisk is part of. The term Many might be
displayed if the VDisk belongs to more than one mapping.
- FC Map Count
- Displays the number of FlashCopy mappings that this
VDisk belongs to.
- UID
- Displays the unit identifier of the VDisk.
- Copies
- Displays the number of VDisk copies. A value greater than one
indicates mirroring is enabled on this VDisk.
Actions
The
following actions are available:
- Yes
- Click this button to recover the VDisk.
- Cancel
- Click this button to exit the panel without recovering the VDisk.