Notes:In this topic:
Adding mirrors to existing virtual disks
Splitting virtual disks to remove mirrors
Converting single virtual disks to dual virtual disks
Converting mirrored virtual disks to dual virtual disks
Also see:
Migrating Virtual Disks From Non-shared Storage Sources to Dual Virtual Disks
Additional mirrors (storage sources) can be added to single or mirrored virtual disks to add another data redundancy level to an existing virtual disk:
o Adding a mirror to a single virtual disk converts it to a mirrored (2 data copies) virtual disk.
o Adding a mirror to a mirrored virtual disk creates a 3-copy virtual disk which has dynamic data resiliency. See Dynamic Data Resiliency for more information.
Notes:
o During this operation the virtual disk undergoes mirror synchronization and will have a temporary Redundancy failed state before the virtual disk goes healthy and on-line. This change is instantaneous and most often will not be noticed unless multiple virtual disks are converted at the same time.
o This operation can be performed while the virtual disk is served to a host, but not if the virtual disk is served to a DataCore Server.
o If the virtual disk is served and there is no path connection between the storage source that has been added and the host, no front-end path will be created.
o A pass-through disk cannot have a virtual disk created from it in order to be included in the list of potential storage sources.
o A virtual disk with a 512 B sector size must be mirrored with a storage source from another pool with a 512 B sector size. A virtual disk with a 4 K sector size can be mirrored with a storage source from a pool with either 4 K or 512 B sector size.
o Sector sizes of multiple virtual disks being converted in the same operation must be the same; either all 512 B or all 4 KB.
o When adding mirrors to multiple virtual disks, there must be an available common server that does not have an existing storage source in the selected virtual disks to use as the storage source for the new mirrors.
o This operation is not supported for dual virtual disks.
To add a mirror:
1 In the Ribbon>Home tab, click Virtual Disks.
2 In the Virtual Disks List, right-click the virtual disk to modify and select Add Mirror.
3 In the Add Mirror dialog box, select the DataCore Server that will be used for the new mirror. Select the Source type and then select the specific source to use from the list.
4 Redundant paths are created by default; clear the Add redundant paths check box to create single paths between the new mirror and the existing virtual disk. (This setting is not available when system managed mirroring is enabled.)
5 Click Add.
Alternatively,
a mirror can be quickly added from the Hosts Panel by right-clicking
on a virtual disk and selecting Add
Mirror from the context menu. This method automatically adds a
mirror to the virtual disk without opening a dialog box. The software
selects the storage source.
The Split and Unserve operation will split or separate one of the storage sources from the virtual disk:
o Splitting a 3-copy virtual disk removes one mirror from that virtual disk, and results in one mirrored virtual disk and one single virtual disk with the same data. The storage source selected to be split will become the single virtual disk.
o Splitting a mirrored virtual disk results in two single virtual disks with the same data.
o A dual virtual disk can also be split, but in this case the operation results in one single virtual disk on one server. (A dual virtual disk cannot be split if it is a snapshot source.)
If the virtual disk is served to a host, the operation will also unserve the storage source selected. Front-end paths to that server are removed and that storage source is unserved from the host. The remaining storage sources remain served.
Splitting and Unserving a mirrored or dual virtual disk will remove high availability and fault tolerance for the virtual disk in the event of a server or pool failure. Splitting and Unserving a 3-copy virtual disk with dynamic data resiliency maintains high availability to the host.
This operation is very useful In the event that a DataCore Server becomes unavailable and unreachable, or a physical disk becomes faulty or missing. In which case, virtual disks can be split in order to extricate the source on the functioning server.
Notes:
o Splitting and unserving a storage source used in a replication is not permitted.
To split and unserve a storage source in a virtual disk:
1 In the DataCore Servers Panel, right-click on the virtual disk, point to Split and Unserve, then select the server with the storage source to split off and unserve from the host (if applicable).
2 Click
Yes on the confirmation
message to continue.
The resulting virtual disks retain the same base name in order to identify
their origin. The resulting virtual disks can then be mirrored
again as required.
This operation is only possible if the single virtual disk was created from a shared disk pool or shared pass-through disk. See Shared Multi-port Array Support for more information.
To convert a single virtual disk that was not created
from a shared disk pool to a dual virtual disk, see Migrating
Virtual Disks From Non-shared Storage Sources to Dual Virtual Disks
in the Shared Multi-port Array Support
topic.
To convert a single virtual disk to a dual virtual disk:
1 In the Virtual Disks List or the DataCore Server Details page>Virtual Disk Tab, right-click on the single virtual disk, point to Convert to Dual and select the desired server from the list.
This operation is only possible if at least one side of the mirrored virtual disk was created from a shared disk pool or shared pass-through disk. See Shared Multi-port Array Support for more information.
To convert a mirrored virtual disk that was
not created from a shared disk pool to a dual virtual disk, see Migrating
Virtual Disks From Non-shared Storage Sources to Dual Virtual Disks
in the Shared Multi-port Array Support
topic.
In order to convert a mirrored virtual disk to a dual virtual disk, the mirrored virtual disk must first be split and unserved. Keep served the side that was created from the shared disk pool that will be used in the dual virtual disk. Unserve the side which will not be used in the dual virtual disk.
To convert a mirrored virtual disk to a dual virtual disk:
1 In the DataCore Servers Panel, right-click on the mirrored virtual disk, point to Split and Unserve, then select the server with the storage source which will not be used in the dual virtual disk. to split off.
2 Click Yes on the confirmation message to continue. This results in two single virtual disks.
3 In the panel, right-click on the single virtual disk that will be used in the dual virtual disk, point to Convert to Dual and select the desired server from the list.