Veritas Volume Manager 5.0 Troubleshooting Guide Guide (September 2006)

34 Recovery from failure of instant snapshot operations
I/O errors during resynchronization
3 Prepare the volume using the following command:
# vxsnap [-g diskgroup] prepare volume [ndcomirs=number] \
[regionsize=size] [drl=yes|no|sequential] \
[storage_attribute ...]
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.
The volume can now be used again for snapshot operations.
Alternatively, you can remove the snapshot volume and recreate it if required.
I/O errors during resynchronization
Snapshot resynchronization (started by vxsnap syncstart, or by specifying sync=on to
vxsnap) stops if an I/O error occurs, and displays the following message on the system
console:
VxVM vxsnap ERROR V-5-1-6840 Synchronization of the
volume volume stopped due to I/O error
After correcting the source of the error, use the following command to restart the
resynchronization operation:
# vxsnap [-b] [-g diskgroup] syncstart volume
See the Veritas Volume Manager Administrator’s Guide and the vxsnap(1M) manual
page for full details of how to use the
vxsnap syncstart command.
I/O failure on a DCO volume
If an I/O failure occurs on a DCO volume, its FastResync maps and DRL log cannot be
accessed, and the DCO volume is marked with the BADLOG flag. DRL logging and
recovery, and instant snapshot operations are not possible with the volume until you
recover its DCO volume using the procedure described in “Recovering a version 20 DCO”
on page 30.
Note: If the I/O failure also affects the data volume, it must be recovered before its DCO
volume can be recovered.