We are running a virtual machine server with multiple virtual machines with ubuntu server edition 12.04 and every so often (usually after updates via webmin it seems), the hard-drive turns into read-only filesystem. Only two of the virtual machines get affected by this problem (that I noticed so far).

What could be causing this issue?

What could we try to fix this problem?

Has anyone else had this problem before? If so, what did you do to fix it?

If I use Aptitude instead of webmin, it will not turn into into a read-only filesystem. Though this could be a coincidence. Could it be a webmin issue?

Thanks.

UPDATE 1

Looks like this is not an update/webmin issue at all. How I know this is because one of the virtual servers is a git server and it turned into a read-only filesystem out of the blue today.

With this new info provided to you, what should I try?

Thanks.