[Copy from RedHat Bugzilla] The real problem is here: [root@dell-pe2950-01 ~]# mount -t nfs -v rhel6-nfs:/export/home /mnt/testdir mount.nfs: timeout set for Fri Oct 14 05:42:43 2011 mount.nfs: trying text-based options 'vers=4,addr=fec0:0:a10:4000:221:5eff:fe95:20f4,clientaddr=fec0:0:a10:4000:213:72ff:fe62:469b' rhel6-nfs:/export/home on /mnt/testdir type nfs (rw) [root@dell-pe2950-01 ~]# mount -t nfs -v rhel6-nfs:/export/home /mnt/testdir mount.nfs: timeout set for Fri Oct 14 05:42:52 2011 mount.nfs: trying text-based options 'vers=4,addr=fec0:0:a10:4000:221:5eff:fe95:20f4,clientaddr=fec0:0:a10:4000:213:72ff:fe62:469b' mount.nfs: mount(2): Device or resource busy ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ mount.nfs: trying text-based options 'vers=4,addr=10.16.64.25,clientaddr=10.16.64.133' rhel6-nfs:/export/home on /mnt/testdir type nfs (rw) mount has already found that this server has been mounted but also fallback to mount it using IPv4. This patch fix this problem. On Fri, Oct 14, 2011 at 3:03 AM, Steve Dickson <SteveD@xxxxxxxxxx> wrote: > > > On 10/13/2011 01:54 PM, Chuck Lever wrote: >> >> On Oct 13, 2011, at 12:59 PM, Steve Dickson wrote: >> >>> Looking further into this issue, I noticed all the following >>> mounts were successful. >>> >>> # mount -o v3 localhost:/home /mnt/home >>> # mount -o v4 localhost:/home /mnt/home >> >> Does this actually change the NFS version in use for /mnt/home, or does the client recognize that this is the same server and export as an existing mount point, and share the cache and mount options? > Using wireshark, I verified that the version does indeed change... > >> >> If the mount options are the same, this is equivalent to >> >> # mount -o v3 localhost:/home /mnt/home >> # mount -o v3 localhost:/home /mnt/home > In this case the second mount does fail with EBUSY.. > > steved. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html