When you run rman, clone or datapump against NFS mount points it may trigger ORA-27054 error.
Oracle recommends:
a) The mount table (eg; /etc/mnttab) can be read to check the mount options
b) The NFS mount is mounted with the "hard" option
c) The mount options include rsize>=32768 and wsize>=32768
d) For RAC environments, where NFS disks are supported, the "noac" mount option is used.
But actually we do NOT need hard option, the workaround is using following mount options. For example, when you just mount disk from production to development. We don't want anything wrong then cause production disk hangs.
rw,forcedirectio,nointr,proto=tcp,suid,rsize=32768,wsize=32768,noac
