CIFS share is loaded with correct permissions - user can manually create files remotely. But when attempting to run PING to backup - user immediately gets the following errors:
CIFS VFS: Received no data, expecting 4
CIFS VFS: Error -32 sending data on socket to server
We found a solution to this problem and decided to share it with this community in case somebody else runs into the same issue.
The problem appears to be caused by Opportunistic Locking being turned on. The workaround is easy. You just have to disable it by running the following command in the PING shell:
echo 0 > /proc/fs/cifs/OplockEnabled
This is going to get overwritten each time PING is re-loaded. Adding it to backup/restore instructions or a script works well so that it is set every time.