Veritas Volume Manager 5.0 Troubleshooting Guide Guide (September 2006)

30 Recovery from hardware failure

Recovery from failure of a DCO volume

5 To snap back the snapshot volume on which you performed a snapclear in the

previous step, use the following command (after using the

vxdg move command to

move the snapshot plex back to the original disk group, if necessary):

# vxplex -f [-g diskgroup] snapback volume snapvol_plex

For the example output, the command would take this form:

# vxplex -f -g mydg snapback vol1 vol1-03

Note: You cannot use vxassist snapback because the snapclear operation

removes the snapshot association information.

Recovering a version 20 DCO

For a version 20 DCO, perform the following steps to recover the DCO volume:

1 Correct the problem that caused the I/O failure.

2Use the vxsnap command to dissociate each full-sized instant snapshot volume that

is associated with the volume:

# vxsnap [-g diskgroup] dis snapvol

For the example output, the command would take this form:

# vxsnap -g mydg dis SNAP-vol1

3 Unprepare the volume using the following command:

# vxsnap [-g diskgroup] unprepare volume

For the example output, the command would take this form:

# vxsnap -g mydg unprepare vol1

4 Start the volume using the vxvol command:

# vxvol [-g diskgroup] start volume

For the example output, the command would take this form:

# vxvol -g mydg start vol1

5 Prepare the volume again using the following command:

# vxsnap [-g diskgroup] prepare volume [ndcomirs=number] \

[regionsize=size] [drl=yes|no|sequential] \

[storage_attribute ...]

For the example output, the command might take this form:

# vxsnap -g mydg prepare vol1 ndcomirs=2 drl=yes

This adds a DCO volume with 2 plexes, and also enables DRL and FastResync (if

licensed).

See the Veritas Volume Manager Administrator’s Guide and the vxsnap(1M)

manual page for full details of how to use the

vxsnap prepare command.