Dell Solutions Enabler 10.0.0 TimeFinder SnapVX CLI User Guide

Description

Syntax

To create a link from snapshot data, use the following syntax:

symsnapvx -sid <SymmID> -sg <SgName> -lnsg <SgName>
          -snap <snapshot_name>
										–snapid <snapsetID>
            [-generation <GenerationNumber>]
            link [-copy [-remote]] [-exact]

Options

-lnsg

Specifies a SG name for target devices.

-generation

Specifies the generation number on the source SG.

-snapid

Specifies the snapsetID on the source SG.

-copy

Specifies copy mode for link operation which performs a background copy to the target device. SnapVX uses Copy mode to create full-volume copies of the data by copying it to the target device's SRP. If Copy mode is not specified when linking the snapshot, the NoCopy link is the default.

-remote

Data is propagated to the remote mirror of the RDF device.

-exact

Pairs source and link devices by their ordinal positions in the selection. If not set, pairs source and link devices by best match.

Examples

To create a Copy mode link to generation 5 of the 600am snapshot, enter:

symsnapvx -sid 001 -sg StorageGroup1 -lnsg StorageGroup2 
-snapshot_name 600am -gen 5 link -copy

It is possible to add volumes to an SG that has active snapshots. The new volumes are included the next time a snapshot is taken. However, the volumes are not included in previously existing snapshots. Linking from a source device that does not have the specified snapshot makes the corresponding target device not ready when the snapshot is from a different generation. This is because there is no data on that target for that time, and the application should not be using that device. The user must decide the best course of action to remove or reintroduce extra volumes. If the SG is relinked to a generation of the snapshot that contains all volumes in the SG, the volumes are automatically made ready and included in the session.

SnapVX behavior when adding source devices provides additional details.

Restrictions

The following restrictions apply when linking to a target:

• When linking to devices do not use devices that are the target of another link copy or another TimeFinder session.
• Devices with persistent track allocations cannot be used as link targets, this includes restores.
• Any pre-existing data that was exclusive to the target is lost during a link or relink.
• The target device must be of equal or greater size than the source device.
  NOTE:By default, SnapVX allows the target device to be larger than the source device. If necessary, this setting can be disabled. The Dell EMC Solutions Enabler CLI Command Reference contains information on changing the Option file parameters.