Supported Snapshot Set Configurations
Snapshot set configuration includes a set of two virtual volumes (source and destination) on the same storage server. The supported snapshot set configurations are presented in the table below, including specific member volumes to use and any restrictions on the use.
In the table, “P” = primary volume, “S” = secondary volume, and “T” = tertiary volume. Multipath Mirror includes the following types: AP, CP, MPIO, or 3rd Party multipath mirrors. Notice any restriction or limitations designated by footnotes described beneath the table.
For instance, referring to the table below, for the case in which the source virtual volume is a standard mirror, the following points describe the supported set configurations and restrictions:
-
To make a configuration without restrictions or limitations, use the primary volume of the source and the destination can be either a linear or the primary volume of a standard mirror.
-
The configuration is valid, but you will not be able to perform a Source Update on the set if the source is the secondary or tertiary volume.
-
If the destination is the primary or secondary volume of a multipath mirror, the configuration is only valid provided that you do not perform write operations to both source and destination simultaneously.
Supported snapshot configurations:
See below for important footnotes. Also note: Virtual volumes created from DP disks or pools cannot be used as snapshot destinations.
|
Source Virtual Volume Type |
Destination Virtual Volume Type |
|
Linear (P) |
Linear (P) |
|
Standard Mirror (P) | |
|
Multipath Mirror (P2,S2) | |
|
Standard Mirror (P,S1,T1) |
Linear (P) |
|
Standard Mirror (P) | |
|
Multipath Mirror (P2,S2) | |
|
Multipath Mirror (P,S,T1) |
Linear (P) |
|
Standard Mirror (P) | |
|
Multipath Mirror (P2,S2) | |
|
Multipath DP Mirror (P,S,T1) |
Linear (P) |
1 Source Update (SU) is not supported.
2 These are advanced functions and should only be performed by advanced users who fully comprehend the ramifications of performing snapshots on this configuration.
WARNING! These advanced functions are only supported with these restrictions:
-
Do NOT create snapshot sets on both primary and secondary volumes of a multipath mirror when the destinations are the primary and secondary sides of another virtual volume.
-
Do NOT perform write operations to both source and destination simultaneously.
-
You are allowed to create a snapshot set in which the destination virtual volume is a multipath mirror, however this virtual volume should not be mounted or accessed unless a Complete Image (CI) command has been performed or it is guaranteed that the active path to the destination virtual volume is from the primary storage server.