Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

Restore SRDF pairs (full)

Full restore copies the entire contents of the target (R2) device to the source (R1) device. After the restore operation completes, the pairs synchronize.

NOTE:Restore operations (incremental or full) are not allowed when the R2 device is larger than the R1 device.

When a restore is initiated for each specified SRDF pair in a device group, the following occurs:

The source (R1) device is write disabled to its local hosts.
The target (R2) device is write disabled to its local hosts.
Traffic is suspended on the SRDF links.
All tracks on the source (R1) device are marked as invalid.
All R1 tracks are refreshed from the R2 side. The track tables are merged between the R1 and R2 side.
Traffic is resumed on the SRDF links.
The source (R1) device is read/write enabled to its local hosts.

In SRDF/S configurations, when the restore control operation has successfully completed and the device pair is in the Synchronized state, the source (R1) device and the target (R2) device contain identical data.

In SRDF/A configurations, when the restore control operation has successfully completed and the device pair is in the Consistent state, the target (R2) device contains dependent write consistent data.

In SRDF/Metro configurations, once the source (R1) device and the target (R2) device contain identical data, the pair state is changed to either ActiveActive or ActiveBias and the R2 side is made RW-accessible to the host(s).

NOTE:

R2 may be set to read/write disabled (not ready) by setting the value of SYMAPI_RDF_RW_DISABLE_R2 to ENABLE in the options file. For more information, refer to the Dell Solutions Enabler CLI Reference Guide

The following image shows restoring an SRDF pair.

Figure 1. Restore (full) an SRDF device

NOTE:

When you issue the symrdf command, device external locks are set on all SRDF devices you are about to establish. See Device external locks and Table 1.

Syntax

Use restore -full for a device group, composite group, storage group, or device file:

symrdf -g DgName restore -full
symrdf -cg CgName restore -full
symrdf -sg SgName restore -full
symrdf -f[ile] FileName restore -full

Include the -use_bias option in SRDF/Metro configurations to indicate that neither the Witness nor vWitness methods of determining bias are used:

symrdf -g DgName restore -full -use_bias
symrdf -cg CgName restore -full -use_bias
symrdf -sg SgName restore -full -use_bias
symrdf -f[ile] FileName restore -full -use_bias

For SRDF/A configurations, the restore operation must include all devices in the group unless the devices are exempt.

For SRDF/Metro configurations:

The restore operation must include all devices in the group.
If the Witness method is used to determine which side of the device pair remains accessible to the host, the Witness groups must be online.

Use the verify command to confirm that the SRDF pairs are in the correct state:


SRDF Mode	State of the SRDF Pairs
SRDF/Synchronous	Synchronized
SRDF/Asynchronous	Consistent
SRDF/Metro	ActiveActive or ActiveBias

Examples

To initiate a full restore on all SRDF pairs in the prod device group:

symrdf -g prod restore -full

To initiate a restore on a list devices in a SRDF/Metro group where bias determines which side of the device pair remains accessible to the host:

symrdf -f /tmp/device_file -sid 085 -rdfg 86 restore -full -use_bias

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Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

Restore SRDF pairs (full)

Syntax

Examples

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