When running OpenStack Compute, using a shared file system or an automated configuration tool, you could encounter a situation where some files on your compute node are using the wrong UID or GID. This causes a number of errors, such as being unable to do live migration or start virtual machines.
The following procedure runs on nova-compute hosts, based on the KVM hypervisor, and could help to
restore the situation:
Procedure 4.9. To recover from a UID/GID mismatch
Ensure you do not use numbers that are already used for some other user/group.
Set the nova uid in
/etc/passwdto the same number in all hosts (for example, 112).Set the libvirt-qemu uid in
/etc/passwdto the same number in all hosts (for example, 119).Set the nova group in
/etc/groupfile to the same number in all hosts (for example, 120).Set the libvirtd group in
/etc/groupfile to the same number in all hosts (for example, 119).Stop the services on the compute node.
Change all the files owned by user
novaor by groupnova. For example:# find / -uid 108 -exec chown nova {} \; # note the 108 here is the old nova uid before the change # find / -gid 120 -exec chgrp nova {} \;Repeat the steps for the libvirt-qemu owned files if those needed to change.
Restart the services.
Now you can run the find command to verify that all files using the correct identifiers.
