I made another interesting discovery this weekend while playing around with the gluster volume deletion option. Prior to creating a volume with a new layout, I went through the documented process to remove my volume:
gluster volume stop glustervol01
Stopping volume will make its data inaccessible. Do you want to continue? (y/n) y Stopping volume glustervol01 has been successful
gluster volume delete glustervol01
Deleting volume will erase all information about the volume. Do you want to continue? (y/n) y Deleting volume glustervol01 has been successful
I then re-created it using the documented process:
gluster volume create glustervol01 replica 2 transport tcp
fedora-cluster01.homefetch.net:/gluster/vol01 fedora-cluster02.homefetch.net:/gluster/vol01** Creation of volume glustervol01 has been successful. Please start the volume to access data.
gluster volume start glustervol01
Starting volume glustervol01 has been successful
Once the new volume was created and started I mounted in on my clients. When I went to access the volume I was quite intrigued to find that the data that was written to the previous gluster volume was still present:
total 24 drwxr-xr-x 126 root root 12288 Nov 26 2011 etc drwxr-xr-x 126 root root 4096 Nov 26 13:07 etc2 drwxr-xr-x 126 root root 4096 Nov 26 13:07 etc3 drwx------ 2 root root 4096 Nov 26 2011 lost+found
Ey? Since ‘gluster delete volume’ spit out the message “Deleting volume will erase all information about the volume”, I figured the contents of the volume would be nuked (never assume, always confirm!). That doesn’t appear to be the case here. When you delete a volume the metadata that describes the volume is the only thing that is removed. It would be helpful if the developers noted this in the output above. I can see this causing headaches for folks down the road.