NFS mount command, long volume name gets truncated and mountpoint string appended to volume name

[John Kittel]

HP-UX 11.11 (ii1 v1) .

I'm trying to mount an NFS volume with a very long host:path (volume name). I used tcpdump to examine what is getting sent out the network, and I can also see in logs on the NFS server, that the mount command that is being sent out from HP-UX has the volume name truncated, and the beginning of the mount point appended to what should be the volume name.

The host:path string in the example I have been working with is 140 characters.

For example, this mount command:

mount frpvf10.kaiseraluminum.com:/vol/FRPVF10_oradata_db2p/.snapshot/smo_db2p_std_20140510_000044_weekly_d_h_1_8a828ad145e4eef20145e
4ef01130001_0   /tmp_mnt

gets sent out the network and seen by the NFS server with the volume name looking like this:

/vol/FRPVF10_oradata_db2p/.snapshot/smo_db2p_std_20140510_000044_weekly_d_h_1_8a828ad145e4eef20145e
4ef0113000/tmp_mnt

Of course the nfs server knows of no such volume, so the mount fails.

If I shorten the string by using the ip address of the nfs server instead of the fqdn, it seems to shorten the name up enough that it works correctly, - the volume name arrives at the nfs server intact, and the mount succeeds.

That is a perfectly fine workaround for me, so this is not an urgent issue, but mainly out of curiosity at this point...

I guess there must be a size limit for the host:path data structure in the mount command? Where is the limit specified, and is it adjustable?

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PS- This thread has been moved from HP-UX>general to networking- Forum Moderator

[Dave Olker]

It's been a long time since I've looked at anything to do with 11.11 NFS, but I think back in the early days there was a path length limit of 128 characters.  That would seem to jive with what you're seeing since the full path with the FQDN is 139 characters but changing the hostname to an IP address gets it down to ~128 characters.  I'm pretty sure we changed this via patches a long time ago and increased the length limit. 

Are both NFS client and server running 11.11?  What NFS patches do you have installed on the NFS client and server?  It looks like the latest NFS cumulative megapatch for 11.11 is PHNE_43577.

Dave

[pooderbill]

>> frpvf10.kaiseraluminum.com:.....

Is there any reason not to use the fully qualified hostname (ie, frpvf10). FQDN's are useful when crossing domains but not necessary within the same domain. That's why there can be multiple aliases in the hosts file as well as DNS:

mount frpvf10:/very_long_source_name/ /mnt1

I would also question the sanity for massively large mountpoint source names on the server. This style of naming may cause many more problems in the future.

[John Kittel]

The NFS server is a new NetApp filer.

The client is HP-UX 11.11. The latest installed NFS patch is PHNE_41023 - ONC/NFS General Release/Performance Patch, from the last 11.11 Gold Quality Pack bundle, GOLDQPK11i(B.11.11.0912.483).

The volume I'm trying to mount is a NetApp snapshot volume created by NetApp software running on another client. I only want to mount it on the HP-UX system so I can use DataProtector to copy it to tape.

The NetApp device and the HP-UX client are in different domains, so I first tried using the fqdn in the mount command (before I found that didn't work and switched to using the ip address). The NetApp software is largely in control of creating the very long volume snapshot name.