Eli,

In my experience testing and fixing this for Cray, NFS export is highly kernel and Lustre version dependent.  I've never tested it with a kernel that recent, but I'm not surprised to see issues.  We do it all the time from SLES11SP2/3 and CentOS (Lustre 2.4/2.5) without issue, but nothing with a kernel version that recent.

There are probably VFS/NFS changes in your kernel that Lustre has not been set up to accomodate.

Perhaps someone else will have more useful experience, but I suspect Lustre patches would be necessary to get that working.

- Patrick

From: HPDD-discuss [hpdd-discuss-bounces@lists.01.org] on behalf of E.S. Rosenberg [esr+hpdd-discuss@mail.hebrew.edu]
Sent: Monday, June 16, 2014 1:49 PM
To: hpdd-discuss@lists.01.org
Subject: [HPDD-discuss] exporting a lustre FS as NFS

In the interest of easy data access from computers that are not part of the cluster we would like to export the lustre filesystem as NFS from one of the nodes.

>From what I understood this should be possible but so far we are getting kernel panics.

So:
- Has anyone done it?
- What are the pitfalls?
- Any other useful tips?

Tech details:
Lustre: 2.4.3
Kernel: 3.14.3 + aufs
Distro: Debian testing/sid

We will probably be upgrading to lustre 2.5.x in the near future.

Thanks,
Eli

Trace from the test subject:
Jun 16 18:07:17 kernel:LustreError: 3795:0:(llite_internal.h:1141:ll_inode2fid()) ASSERTION( inode != ((void *)0) ) failed:
Jun 16 18:07:17 kernel:LustreError: 3795:0:(llite_internal.h:1141:ll_inode2fid()) LBUG
Jun 16 18:07:17 kernel:CPU: 0 PID: 3795 Comm: nfsd Tainted: G        WC   3.14.3-aufs-mos-1 #1
Jun 16 18:07:17 kernel:Hardware name: Dell Inc. PowerEdge C6220/03C9JJ, BIOS 1.2.1 05/27/2013
Jun 16 18:07:17 kernel: 0000000000000000 ffff881047dd5ba0 ffffffff8175c9e4 ffffffffa1842970
Jun 16 18:07:17 kernel: ffff881047dd5bc0 ffffffffa006954c 0000000000000000 ffff880845cd5148
Jun 16 18:07:17 kernel: ffff881047dd5c00 ffffffffa18054fd 0cb158b46edf5345 0000000000000013
Jun 16 18:07:17 kernel:Call Trace:
Jun 16 18:07:17 kernel: [<ffffffff8175c9e4>] dump_stack+0x45/0x56
Jun 16 18:07:17 kernel: [<ffffffffa006954c>] lbug_with_loc+0x3c/0x90 [libcfs]
Jun 16 18:07:17 kernel: [<ffffffffa18054fd>] ll_encode_fh+0x109/0x13e [lustre]
Jun 16 18:07:17 kernel: [<ffffffff81203f79>] exportfs_encode_inode_fh+0x1b/0x86
Jun 16 18:07:17 kernel: [<ffffffff8120402f>] exportfs_encode_fh+0x4b/0x60
Jun 16 18:07:17 kernel: [<ffffffff810f420f>] ? lookup_real+0x27/0x42
Jun 16 18:07:17 kernel: [<ffffffff81207689>] _fh_update.part.7+0x39/0x48
Jun 16 18:07:17 kernel: [<ffffffff81207c2a>] fh_compose+0x3d1/0x3fa
Jun 16 18:07:17 kernel: [<ffffffff81210fe4>] encode_entryplus_baggage+0xd3/0x125
Jun 16 18:07:17 kernel: [<ffffffff8121121f>] encode_entry.isra.14+0x150/0x2cb
Jun 16 18:07:17 kernel: [<ffffffff8121247d>] nfs3svc_encode_entry_plus+0xf/0x11
Jun 16 18:07:17 kernel: [<ffffffff81209e7e>] nfsd_readdir+0x160/0x1f8
Jun 16 18:07:17 kernel: [<ffffffff8121246e>] ? nfs3svc_encode_entry+0xe/0xe
Jun 16 18:07:17 kernel: [<ffffffff8120831b>] ? nfsd_splice_actor+0xe8/0xe8
Jun 16 18:07:17 kernel: [<ffffffff81056154>] ? groups_free+0x22/0x44
Jun 16 18:07:17 kernel: [<ffffffff8120fa3d>] nfsd3_proc_readdirplus+0xe3/0x1df
Jun 16 18:07:17 kernel: [<ffffffff81205269>] nfsd_dispatch+0xca/0x1ad
Jun 16 18:07:17 kernel: [<ffffffff8173579b>] svc_process+0x469/0x768
Jun 16 18:07:17 kernel: [<ffffffff81204d39>] nfsd+0xc5/0x117
Jun 16 18:07:17 kernel: [<ffffffff81204c74>] ? nfsd_destroy+0x6b/0x6b
Jun 16 18:07:17 kernel: [<ffffffff81051764>] kthread+0xd6/0xde
Jun 16 18:07:17 kernel: [<ffffffff8105168e>] ? kthread_create_on_node+0x15d/0x15d
Jun 16 18:07:17 kernel: [<ffffffff8176400c>] ret_from_fork+0x7c/0xb0
Jun 16 18:07:17 kernel: [<ffffffff8105168e>] ? kthread_create_on_node+0x15d/0x15d