8.14. Troubleshooting
- Situation
Snapshot creation fails.
Step 1Check if the bricks are thinly provisioned by following these steps:
- Execute the
mount
command and check the device name mounted on the brick path. For example:# mount /dev/mapper/snap_lvgrp-snap_lgvol on /rhgs/brick1 type xfs (rw) /dev/mapper/snap_lvgrp1-snap_lgvol1 on /rhgs/brick2 type xfs (rw)
- Run the following command to check if the device has a LV pool name.
lvs device-name
For example:# lvs -o pool_lv /dev/mapper/snap_lvgrp-snap_lgvol Pool snap_thnpool
If thePool
field is empty, then the brick is not thinly provisioned. - Ensure that the brick is thinly provisioned, and retry the snapshot create command.
Step 2Check if the bricks are down by following these steps:
- Execute the following command to check the status of the volume:
# gluster volume status VOLNAME
- If any bricks are down, then start the bricks by executing the following command:
# gluster volume start VOLNAME force
- To verify if the bricks are up, execute the following command:
# gluster volume status VOLNAME
- Retry the snapshot create command.
Step 3Check if the node is down by following these steps:
- Execute the following command to check the status of the nodes:
# gluster volume status VOLNAME
- If a brick is not listed in the status, then execute the following command:
# gluster pool list
- If the status of the node hosting the missing brick is
Disconnected
, then power-up the node. - Retry the snapshot create command.
Step 4Check if rebalance is in progress by following these steps:
- Execute the following command to check the rebalance status:
gluster volume rebalance VOLNAME status
- If rebalance is in progress, wait for it to finish.
- Retry the snapshot create command.
- Situation
Snapshot delete fails.
Step 1Check if the server quorum is met by following these steps:
- Execute the following command to check the peer status:
# gluster pool list
- If nodes are down, and the cluster is not in quorum, then power up the nodes.
- To verify if the cluster is in quorum, execute the following command:
# gluster pool list
- Retry the snapshot delete command.
- Situation
Snapshot delete command fails on some node(s) during commit phase, leaving the system inconsistent.
Solution- Identify the node(s) where the delete command failed. This information is available in the delete command's error output. For example:
# gluster snapshot delete snapshot1 Deleting snap will erase all the information about the snap. Do you still want to continue? (y/n) y snapshot delete: failed: Commit failed on 10.00.00.02. Please check log file for details. Snapshot command failed
- On the node where the delete command failed, bring down glusterd using the following command:
# service glusterd stop
Important
Ifglusterd
crashes, there is no functionality impact to this crash as it occurs during the shutdown. For more information, see Section 23.3, “Resolvingglusterd
Crash” - Delete that particular snaps repository in
/var/lib/glusterd/snaps/
from that node. For example:# rm -rf /var/lib/glusterd/snaps/snapshot1
- Start glusterd on that node using the following command:
# service glusterd start.
- Repeat the 2nd, 3rd, and 4th steps on all the nodes where the commit failed as identified in the 1st step.
- Retry deleting the snapshot. For example:
# gluster snapshot delete snapshot1
- Situation
Snapshot restore fails.
Step 1Check if the server quorum is met by following these steps:
- Execute the following command to check the peer status:
# gluster pool list
- If nodes are down, and the cluster is not in quorum, then power up the nodes.
- To verify if the cluster is in quorum, execute the following command:
# gluster pool list
- Retry the snapshot restore command.
Step 2Check if the volume is in
Stop
state by following these steps:- Execute the following command to check the volume info:
# gluster volume info VOLNAME
- If the volume is in
Started
state, then stop the volume using the following command:gluster volume stop VOLNAME
- Retry the snapshot restore command.
- Situation
Snapshot commands fail.
Step 1Check if there is a mismatch in the operating versions by following these steps:
- Open the following file and check for the operating version:
/var/lib/glusterd/glusterd.info
If theoperating-version
is lesser than 30000, then the snapshot commands are not supported in the version the cluster is operating on. - Upgrade all nodes in the cluster to Red Hat Gluster Storage 3.2 or higher.
- Retry the snapshot command.
- Situation
After rolling upgrade, snapshot feature does not work.
SolutionYou must ensure to make the following changes on the cluster to enable snapshot:
- Restart the volume using the following commands.
# gluster volume stop VOLNAME # gluster volume start VOLNAME
- Restart glusterd services on all nodes.
# service glusterd restart