Diagnosis Guide

Actions

Action 1 - Check disks

Check to see which disks were used for installation, by issuing the splstdata -b command. If the disks are not valid, change the set of disks by issuing the spchvgobj command, and reinstall the node.

Action 2 - Check disk allocation

A physical volume can belong to only one volume group at a time. If you specified a list of disks for installation and one of the disks is in use by another volume group, you must remove the disk from the other volume group. Use the reducevg command to remove the disk, and then reinstall the node.

Action 3 - Force the Root Volume Group extension

A physical volume can belong to only one volume group at a time. If you attempt to extend the root volume group with a disk that is in use by another volume group, the extendvg command fails. If the disk is part of an inactive volume group, you can force the extension of the root volume group by specifying the -f (force) option. Use the spmirrorvg -f command.

Action 4 - Unlock the Root Volume Group

If a process terminated and left the volume group in a locked state, do the following:

1. Unlock the root volume group by issuing the chvg -r command.
2. Rerun the desired mirroring function, using the spmirrorvg command if mirroring is desired or the spunmirrorvg command if unmirroring is desired.

Action 5 - Add space to physical volumes

When mirroring, there must be enough total space on the additional physical volumes to contain all of AIX's logical volumes and still maintain strictness. Strictness is defined in Root Volume Group terminology. If there is not enough space in the additional physical volumes, add additional physical volumes to the root volume group by issuing the spchvgobj command. Then rerun mirroring using the spmirrorvg command.

Action 6 - Add physical volumes to the Root Volume Group

For each copy of AIX, you must have at least one physical volume in the root volume group. For example, if you have specified three copies of the root volume group (the original and two copies), you must have at least three physical volumes in the root volume group. If you have fewer physical volumes than copies, add additional disks to the physical volume list by issuing the spchvgobj command. Then, rerun mirroring by issuing the spmirrorvg command.

Action 7 - Verify the number of copies of AIX on the node for mirroring

To mirror successfully, you must specify more copies of AIX than are currently in effect on the node. For example, if there is one copy of the root volume group in effect on the node, you must specify two or three as the desired number of copies for mirroring. If there are two copies of the root volume group in effect, you must specify three copies for mirroring. If you specify the same number or fewer copies than are currently in effect on the node, mirroring has no effect.

Determine how many copies of the root volume group are currently in effect for the node and correct this number with these commands:

1. Use the splstdata command to find out how many copies of the root volume group are in effect for the node.
2. Use the spchvgobj command to change the number of desired copies.
3. Rerun the spmirrorvg command.

Action 8 - Verify the number of copies of AIX on the node for unmirroring

To unmirror successfully, you must specify fewer copies of AIX than are currently in effect on the node. For example, if there are three copies of the root volume group in effect on the node, you must specify one or two as the desired number of copies for unmirroring. If there are two copies of the root volume group in effect, you must specify one for unmirroring. If you specify the same number or more copies than are currently in effect on the node, unmirroring has no effect.

Determine how many copies of the root volume group are currently in effect for the node and correct this number with these commands:

1. Use the splstdata -v command to find out how many copies of the root volume group are in effect for the node.
2. Use the spchvgobj command to change the number of desired copies.
3. Rerun the spunmirrorvg command.

Action 9 - Check for user logical volumes on the physical volume

The root volume group may not be reduced by a physical volume unless all the logical volumes have been removed from the physical volume. During the unmirroring operation, all the AIX logical volumes are removed from the mirror's physical volumes. However, if additional (user) logical volumes were created on the physical volume, you cannot reduce the root volume group by the physical volume until all user logical volumes are moved or deleted.

Action 10 - Verify mirroring or unmirroring

Use this table to perform verification tasks for the root volume group.

Table 13. Verification of mirroring or unmirroring for Root Volume Groups