Replacing a Volume in a Virtual Volume

Primary, secondary, or tertiary volumes in a virtual volume can be replaced with other available candidate volumes. Replacing a volume will adjust all mirror and application server mappings. Mirrors will be synchronized after replacement with a full recovery; but in the case of linear virtual volumes, data is not copied.

If a mirrored virtual volume is served to an application server, a volume from the primary (preferred) or alternate  server can be replaced using a volume from the same server without the client losing access to the virtual volume.

Candidate volumes may be:

  • From the same server.

  • From a different server in the same region (see the Parent Server column in the Replacement Candidates area in the dialog box below).

Note: AP mirrors cannot receive a replacement from a different server.

  • Replacements must be equal to or greater than the virtual volume size.

  • If the virtual volume is mapped, candidate volumes will originate from servers that have target channels of the same type (iSCSI or FC) as the original initiator channels on the application server. (Although the storage or application server channel may be disconnected at the time of replacement, the potential to make a connection must exist.)

  • Must be the same type. Static volumes (partition-based volumes or static NMVs) can only be replaced by other static volumes. Volumes from dynamic NMV pools can only be replaced by other volumes from dynamic pools. There are some exceptions to this rule:  

    • Static volumes can be replaced by volumes from dynamic NMV pools if:

      1. Dynamic pools must have sufficient SAUs available.

      2. The virtual volume must be unmapped. (Unmap and apply before running replacing your volume.)

If you are upgrading from static volumes to dynamic in a mirror, replace both volumes before mapping to the application server.

    • In special cases, such as when a pool is offline or if proxy volumes are involved, it may be necessary to replace a dynamic volume with a static volume. If this is the case, you must enable a configuration preference to allow it. You can enable this preference in the Candidate Volumes dialog box using the instructions below. (Refer to Allow Mixed Static and Dynamic Disks for important instructions before proceeding.

The configuration preference, Allow mixing static and dynamic disks, will remain enabled until cleared. The option can be disabled (or enabled) from Preferences>Configuration Preferences in the SANmanager Menu bar.  

Candidate volumes cannot be:

  •  The Traveller volume in a Traveller-enabled virtual volume cannot be replaced; they can only be deleted and recreated.

Special considerations for replacing volumes:

  • If a volume to be replaced is a member of a snapshot relationship or AIM set, disable the snapshot relationship or AIM set before replacing the volume. Replacing a volume in an enabled snapshot relationship or AIM set can produce unpredictable results.

  • After replacing volumes in a mirror, you must allow time for synchronization before making other configuration changes to the virtual volume.

  • IMPORTANT: If a virtual volume is mapped to an application server, and you are replacing a mirror volume of a 3rd party AP/MPIO (3PAP), AP or cluster path (CP) virtual volume OR the primary volume of a standard mirror with another volume from a different storage server in the region, stop all I/O on the application server until the volume has been replaced and the configuration is applied. (It is not necessary to stop I/O on the application server if replacing the secondary volume in a standard mirror with another volume from a different storage server in the region.)

Renaming replacement volumes

You can choose not to rename the replacement volume, or to rename it to the name of the volume that is being replaced. The name of the volume that was replaced will be appended with the identifier “_Old.” The volume that was replaced will be marked as “previously used” until the configuration is applied.  

To replace a volume in a virtual volume:

  1. In the SANmanager Virtual Volumes tab, select the virtual volume from the Virtual Volume folder in the lower-left pane.

  2. In the lower-right pane, select the volume to be replaced from the list of volumes and choose Replace from the context menu to open the Candidate Volumes dialog box.

SANsymphony candidatevols db Replacing a Volume in a Virtual Volume

 

  1. In the Volume Naming Options area, make a selection on renaming the replacement volume.

  2. In special cases, it may be necessary to replace static volumes (partition-based volumes or static NMV) with dynamic volumes from NMV pools. Refer to Allow Mixed Static and Dynamic Disks before enabling the Allow mixing static and dynamic disks check box in the Mixing Data Types area.

  3. In the Replacement Candidates area, select a replacement.

  4. Click Replace.

  5. Apply the configuration changes.

  6. Wait for the mirror to synchronize before making more configuration changes to the virtual volume.

Replacing a Volume in a Virtual Volume