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Converting a non-CDS disk group to a CDS disk group

 To convert a non-CDS disk group to a CDS disk group

  1. If the disk group contains one or more disks that you do not want to convert to CDS disks, use the vxdg move or vxdg split command to move the disks out of the disk group.
  2. The disk group to be converted must have the following characteristics:
  3. If the disk group does not have a CDS-compatible disk group alignment, the objects in the disk group must be relayed out with a CDS-compatible alignment.
  4. If the conversion is not going to performed on-line (that is, while access to the disk group continues), stop any applications that are accessing the disks.
  5. Type one of the following forms of the CDS conversion utility (vxcdsconvert) to convert a non-CDS disk group to a CDS disk group.

    # vxcdsconvert -g diskgroup [-A] [-d defaults_file] \

      [-o novolstop] alignment [attribute=value] ...

    # vxcdsconvert -g diskgroup [-A] [-d defaults_file] \

      [-o novolstop] group [attribute=value] ...

The alignment and group keywords have the following effect

alignment 

Specifies alignment conversion where disks are not converted, and an object relayout is performed on the disk group. A successful completion results in an 8K-aligned disk group. You might consider this option, rather than converting the entire disk group, if you want to reduce the amount of work to be done for a later full conversion to CDS disk group. 

group 

Specifies group conversion of all non-CDS disks in the disk groupbefore realying out objects in the disk group. 

The conversion involves evacuating objects from the disk, reinitializing the disk, and relocating objects back to disk. You can specify the -o novolstop option to perform the conversion on-line (that is, while access to the disk group continues). If the -o novolstop option is not specified, stop any applications that are accessing the disks, and perform the conversion off-line.

Warning: Specifying the -o novolstop option can greatly increase the amount of time that is required to perform conversion.

Conversion has the following side effects:

In the following example, the disk group, anodg, and all its disks are converted to CDS while keeping its volumes are still online:

# vxcdsconvert -g anodg -o novolstop group \

  move_subdisks_ok=yes evac_subdisks_ok=yes \

  evac_disk_list=anodg11,anodg12,anodg13,anodg14

The evac_disk_list attrinute specifies a list of disks (nodg11 through anodg14) to which subdisks can be evacuated to disks if required.

Before you use the vxcdsconvert command, make sure you understand its options, attributes, and keywords.

See the vxcdsconvert(1M) manual page.