In ETERNUS DX/AF thin devices or flex volumes (and also snap data volumes) can be used as snap volumes.
For an original unit only homogeneous snap units can be used, i.e. either thin devices or flex volumes or snap data volumes.
For all volumes of a pubset either thin devices or flex volumes should be used.
A configuration and reservation of storage capacity for the existing snap data volumes and snap data pools for the usage of SnapOPC+ is no longer necessary.
Snap data volumes and snap data pools can still be used for ETERNUS AF und ETERNUS DX S3 for compatibility reasons.
Automatic selection of snap units
The SNAP-UNIT = *AUTO-SELECT operand in the /START-SNAP-SESSION command is used for automatic selection of suitable BS2000 volumes as snap units.
This is important in particular when using the "Snapsets" function (see the “Introduction to System Administration” manual [5]) .
When BS2000 volumes are to be used automatically as snap units, they must be initialized in advance with the VOLIN utility (see the “Utility Routines” manual [8]).
The special notation S#<mn> is introduced as the VSN for these volumes, e.g. S#5234, where <mn> is the device mnemonic.
Such volumes prepared especially in BS2000 for the *AUTO-SELECT option are not displayed with the UNUSED status in the /SHOW-SNAP-SESSION-STATUS command. Selection in the /SHOW-STORAGE-DEVICE-CONFIG command also has no effect for these volumes.
When the snap session is terminated with /STOP-SNAP-SESSION, the special VSN S#<mn> can be discarded or reconstructed with the SNAP-UNIT=*DESTROY/*UNUSED operand. When the special VSN is reconstructed, the volume is still included in the automatic selection.