Wandering Thoughts: Recent Entries For 2006/12/31

A (Solaris 8) automounter irritation

Here's an automounter irritation that keeps biting us: on fileservers, the Solaris 8 automounter is not smart enough to notice when an underlying /export/<whatever> mount point has been unmounted.

If it gets a request for the filesystem, it 'mounts' things anyways, which then fouls up various aspects of, say, remounting the real filesystems. It is remarkably difficult to persuade the automounter to let go so that you can restore things to normality, and you can't just shoot the entire automounter without decimating the overall system.

(We think that the usual way the automounter gets a request for the filesystem is for mail delivery to need to look at someone's .forward, but the system is reasonably opaque so we're not entirely sure.)

It wouldn't be too difficult for the automounter to notice this situation and do the right thing. Even if it didn't, we'd be happy if there was some way to tell the automounter to temporarily stop serving a mount point (short of editing the automounter maps, which has various drawbacks).

And failing all that, the automounter really needs a way to be told to immediately time out and unmount some mount it's done. Maybe umount theoretically does this, but it sure doesn't seem to work reliably for us in practice. (Possibly this is due to whatever keeps getting the automounter to mount the filesystems.)