Sleeping in a /vol
If running “ls -l /” stalls but the same command to any other directory works seamlessly then most probably you’re hitting the following issue. To confirm that use truss:
# truss ls -l
.
.
.
lstat64("/vol", 0xFFBFF8E8) (sleeping...)
Additionally try “grep /var/adm/message” for NFS errors:
# grep NFS /var/adm/messages NFS server for volume management (/vol) not responding still trying
If everything matches then simply “umount /vol” (use -f to forcibly unmount). This issue happens because of the discrepancy between what is written in /etc/mnttab and the actual state of affairs. In my case it was:
# grep "/vol" /etc/mnttab ss5:vold(pid4985) /vol nfs ignore,noquota,dev=5300004 1248249505
But there wasn’t such pid in the process list:
# ps -ef | grep 4985 root 5941 6705 0 13:29:34 pts/5 0:00 grep 4985
Once you manage to umount /vol everything should return back to normal.