I have a Solaris 10 server with autofs-mounted home dirs. On one server they are not unmounted after the 10 min timeout period. We've got
/etc/default/autofs, I ran
automount -t 600, disabled and re-enabled
svc:/system/filesystem/autofs:default service and nothing seems to work.
My suspicion is that something on the system is periodically accessing all the mounted filesystems, maybe checking if they are accessible, and thus resetting the automounter timeout that in turn never expires. This is supported by a test I just did - if I set the timeout to 10 seconds the mountpoints are unmounted, looks like 10 sec is shorter than the period in which that something is doing the checks and the timer has a chance to expire.
The question is how can I find what process is doing that? The server is a heavily used production system and I can't do any dangerous experiments on it.
Note that the filesystems are not kept open and can be manually unmounted. That something is probably going mountpoint by mountpoint, cd in, cd out, move on, often enough to prevent
automount from unmounting it. But it doesn't keep it open and therefore is not visible with
fuser -c. I want to catch it or record it as soon as it accesses the mountpoints to know what's doing it.
FWIW it's a Solaris 10 zone on rather beefy Solaris 10 host (Sparc / M5000).