I have quite an odd issue where my nested NFS mounts just disappear randomly from time to time.
The fstab entries look somewhat like this:
nfs:/home /home nfs rw,hard,intr,rsize=32768,noatime,nocto,proto=tcp 0 0 nfs:/bigdir /home/bigdir nfs rw,hard,intr,rsize=32768,noatime,nocto,proto=tcp,bg 0 0
The issue is that from time to time the "/home/bigdir" folder will be empty, even though mtab think that the share is still mounted. nfsstat et. al. do also think the share is still mounted.
Only thing that works is by unmounting, and then (re)mounting the bigdir share.
The server side is a NetApp. The client side is RHEL5.5, 2.6.18-194 kernel (Yes, I know 5.8 is out, but as far as I can see there are no erratas for this particular issue).
I can use various hacks like automount, or mounting it to another path and then using --mount bind, but I would like to fix the underlying issue.