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Resizing the SRL

The size of the SRL must be large enough to meet the constraints explained in the section "Sizing the SRL" in the Veritas Volume Replicator Planning and Tuning Guide. These constraints can change with the changes in the business needs, application write rate, available network bandwidth, and so on. As a result, it is necessary to determine the appropriate size of the SRL again. This section includes the following tasks:

  Increasing the size of the SRL on the Primary and the Secondary

  Decreasing the size of the SRL on the Primary

  Decreasing the size of the SRL on the Secondary

Increasing the size of the SRL on the Primary and the Secondary

VVR enables you to increase the size of the Primary SRL and the Secondary SRL in a Replicated Data Set (RDS) using the vradmin resizesrl command, even while the application is active or while replication is in progress. The vradmin resizesrl command increases the size of the SRL in the RDS on the Primary, on any valid Secondaries, and on the bunker node, if present. A valid Secondary is one that is correctly configured; that is, it does not have configuration errors. Use the vradmin -l printrvg command to view the configuration status of the RDS. The vradmin resizesrl command does not resize the SRL on any Secondary that has configuration errors.

Before increasing the size of the SRL, do the following:

  On each host in the RDS, check whether there is enough free space in the disk group in which the SRL resides by issuing the following command:

# vxdg -g diskgroup free

If any host does not have enough space to resize the SRL, the resizesrl command will fail.

 To increase the size of the SRL on the Primary and the Secondary

Issue the following command on any host in the RDS:

# vradmin -g diskgroup resizesrl [-f] local_rvgname length

The argument local_rvgname is the name of the RVG on the local host and represents its RDS.

The argument length is the desired size for the Primary SRL. The length can be specified using the standard VxVM conventions. It can be prefixed by a plus sign (+) to indicate an increase in the size of the Primary SRL by the specified amount.

Use the -f option for the vradmin resizesrl command to resize the Primary SRL even if the Secondary or Bunker hosts do not have enough space to increase the SRL. This option may be necessary to protect the Primary SRL from overflow. With the -f option, the command succeeds and resizes the Primary SRL provided that the Primary has enough space. The command also attempts to resize the Secondary SRL and the Bunker SRL, if present. However, if any Secondary or Bunker host does not have enough free space to increase the SRL size, the resize operation fails on that host.

Decreasing the size of the SRL on the Primary

For instructions on decreasing the size of the SRL on the Primary, see Decreasing the size of the SRL on the Primary.

Decreasing the size of the SRL on the Secondary

Note that you do not have to stop the applications while resizing the Secondary SRL.

 To decrease the size of the SRL on the Secondary

1. Detach the RLINK:

   # vxrlink -g diskgroup det rlink_name

2. Dissociate the SRL from the RVG.

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     Note   Any checkpoints that you have created will be lost after dissociating the SRL.

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   # vxvol -g diskgroup dis srl_name

3. Decrease the size of the SRL using the vxassist command. For example, to decrease the size of the SRL:

   # vxassist -g diskgroup growto srl_name new_length

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     Note   We recommend that the SRL reside on disks that are not being used for the data volumes. We also recommend that the Primary and the Secondary SRLs be the same size. See the vxassist(1M) manual page for more information.

   ---

4. Reassociate the SRL with the RVG:

   # vxvol -g diskgroup aslog rvg_name srl_name

5. Attach the RLINK:

   # vxrlink -g diskgroup att rlink_name