Mucking with a mounted filesystem?

[Michael ODonnell]

> I am running into a disk space issue on an older server.  I'd like
> to do a tune2fs -m 1 (or maybe 0) to get rid of most, if not all of
> the reserved block space on the partition that is close to full.
> The disk is actually an iSCSI volume mounted from an EqualLogic
> array, and then exported via NFS to 6 other servers.
>
> Has anyone ever run tune2fs on a mounted/in-use filesystem?
> Is this safe to do?

I don't know specifically whether that's safe to do with a mounted
filesystem but if your situation allows you might be able to
accomplish it by first doing an on-the-fly remount such that your
filesystem is temporarily ReadOnly, then do your tune2fs thing,
then restore ReadWrite mode with another on-the-fly remount:

   mount -oremount,ro /your/filesystem
   tune2fs -whatever /dev/yourDevice
   mount -oremount,rw /your/filesystem