Making shared volume groups enhanced concurrent capable on AIX®

If your shared volume groups are not enhanced concurrent capable, when a node crashes, the disks are locked and the remote node is not able to access the disk. To avoid this situation, make the shared volume group enhanced concurrent capable.

Note:
  1. Ensure that the package bos.clvm.enh is installed on your system.
  2. System Automation for Multiplatforms supports enhanced concurrent capable volume groups in non-concurrent mode when using resources of classes IBM.AgFileSystem or IBM.VolumeGroup within the policy. System Automation for Multiplatforms does not support the concurrent mode of enhanced concurrent volume groups and the contained filesystem as resources within the policy. Support for enhanced concurrent volume groups can be explicitly provided by a policy provider using IBM.Application resources to manage the filesystem on top of the enhanced concurrent volume groups.

Before you make the volume group enhanced concurrent capable, use the lsvg command to view information about the shared volume group:

# lsvg vgERSTZ0
VOLUME GROUP:       vgERSTZ0                 VG IDENTIFIER: 
00c31bfe00004c0000000118c2f1ead2
VG STATE:           active                   PP SIZE:        4 megabyte(s)
VG PERMISSION:      read/write               TOTAL PPs:      255 (1020
megabytes)
MAX LVs:            256                      FREE PPs:       14 (56 megabytes)
LVs:                2                        USED PPs:       241 (964 megabytes)
OPEN LVs:           2                        QUORUM:         2 (Enabled)
TOTAL PVs:          1                        VG DESCRIPTORS: 2
STALE PVs:          0                        STALE PPs:      0
ACTIVE PVs:         1                        AUTO ON:        no
MAX PPs per VG:     32512
MAX PPs per PV:     1016                     MAX PVs:        32
LTG size (Dynamic): 256 kilobyte(s)          AUTO SYNC:      no
HOT SPARE:          no                       BB POLICY:      relocatable
To make a volume group enhanced concurrent capable using SMIT:
  1. Enter the following command: 
    # smitty vg

    Text similar to the following is displayed:

          Set Characteristics of a Volume Group
          Change a Volume Group

* VOLUME GROUP name                                   vgERSTZ0
* Activate volume group AUTOMATICALLY                 no                     +
    at system restart?
* A QUORUM of disks required to keep the volume       yes                    +
   group on-line ?
  Convert this VG to Concurrent Capable?              enhanced concurrent
  2. Press ENTER.
To make the volume group enhanced concurrent capable from the command line, enter: 
# /usr/sbin/chvg -a'n' -Q'y' '-C' <VOLUME_GROUP_NAME>

After you made the volume group enhanced concurrent capable, the lsvg command returns information similar to the following example output:

# lsvg vgERSTZ0
VOLUME GROUP:       vgERSTZ0                 VG IDENTIFIER: 
00c31bfe00004c0000000118c2f1ead2
VG STATE:           active                   PP SIZE:        4 megabyte(s)
VG PERMISSION:      read/write               TOTAL PPs:      255 (1020
megabytes)
MAX LVs:            256                      FREE PPs:       14 (56 megabytes)
LVs:                2                        USED PPs:       241 (964 megabytes)
OPEN LVs:           2                        QUORUM:         2 (Enabled)
TOTAL PVs:          1                        VG DESCRIPTORS: 2
STALE PVs:          0                        STALE PPs:      0
ACTIVE PVs:         1                        AUTO ON:        no
Concurrent:         Enhanced-Capable         Auto-Concurrent: Disabled
VG Mode:            Non-Concurrent
MAX PPs per VG:     32512
MAX PPs per PV:     1016                     MAX PVs:        32
LTG size (Dynamic): 256 kilobyte(s)          AUTO SYNC:      no
HOT SPARE:          no                       BB POLICY:      relocatable