samba (smbfs) problems: bad superblock error on mount
At work today, we had this problem, and I wasted a long time trying to figure it out. Basically, we have a machine that serves up a big disk over smb/cifs/netbios/whatever you want to call it. There are something like 120 machines that are supposed to mount this as a file system using the smbfs that is now built in to the Linux kernel. We are using mostly FC3, but are switching over to CentOS, to get a little more stability. Pretty soon we'll have over 200 machines, and it's a pain to upgrade them all.
But the problem was that batches of them would get "bad superblock error or too many mounts" when they tried to mount the file system. At first I thought that there was some quota or limit on the samba server side, and we just had too many clients mounting the file system. That wasn't the problem.
Then I noticed that the failure seemed to correlate with slight variations in kernel on the client side. It wasn't perfect, and it turned out to not be the problem either.
The problem was, in fact, that the smbfs kernel module just does not work if the "samba-client" RPM is not installed on the machine. The kernel module is there. It just needs the client libraries to work. It would have been real nice if the error was "oh gosh, samba library not found" instead of "bad superblock." Oh well. The fix was simple:
yum -y install samba-client
on all the affected machines.