From: Graham Cobb <g.btrfs@cobb.uk.net>
To: linux-btrfs@vger.kernel.org
Subject: Re: Re: nfs subvolume access?
Date: Wed, 10 Mar 2021 09:35:10 +0000 [thread overview]
Message-ID: <5bded122-8adf-e5e7-dceb-37a3875f1a4b@cobb.uk.net> (raw)
In-Reply-To: <20210310080940.GB2158@tik.uni-stuttgart.de>
On 10/03/2021 08:09, Ulli Horlacher wrote:
> On Wed 2021-03-10 (07:59), Hugo Mills wrote:
>
>>> On tsmsrvj I have in /etc/exports:
>>>
>>> /data/fex tsmsrvi(rw,async,no_subtree_check,no_root_squash)
>>>
>>> This is a btrfs subvolume with snapshots:
>>>
>>> root@tsmsrvj:~# btrfs subvolume list /data
>>> ID 257 gen 35 top level 5 path fex
>>> ID 270 gen 36 top level 257 path fex/spool
>>> ID 271 gen 21 top level 270 path fex/spool/.snapshot/2021-03-07_1453.test
>>> ID 272 gen 23 top level 270 path fex/spool/.snapshot/2021-03-07_1531.test
>>> ID 273 gen 25 top level 270 path fex/spool/.snapshot/2021-03-07_1532.test
>>> ID 274 gen 27 top level 270 path fex/spool/.snapshot/2021-03-07_1718.test
>>>
>>> root@tsmsrvj:~# find /data/fex | wc -l
>>> 489887
>
>> I can't remember if this is why, but I've had to put a distinct
>> fsid field in each separate subvolume being exported:
>>
>> /srv/nfs/home -rw,async,fsid=0x1730,no_subtree_check,no_root_squash
>
> I must export EACH subvolume?!
I have had similar problems. I *think* the current case is that modern
NFS, using NFS V4, can cope with the whole disk being accessible without
giving each subvolume its own FSID (which I have stopped doing).
HOWEVER, I think that find (and anything else which uses fsids and inode
numbers) will see subvolumes as having duplicated inodes.
> The snapshots are generated automatically (via cron)!
> I cannot add them to /etc/exports
Well, you could write some scripts... but I don't think it is necessary.
I *think* it is only necessary if you want `find` to be able to cross
between subvolumes on the NFS mounted disks.
However, I am NOT an NFS expert, nor have I done a lot of work on this.
I might be wrong. But I do NFS mount my snapshots disk remotely and use
it. And I do see occasional complaints from find, but I live with it.
next prev parent reply other threads:[~2021-03-10 9:36 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210613115313.BC59.409509F4@e16-tech.com>
2021-03-10 7:46 ` nfs subvolume access? Ulli Horlacher
2021-03-10 7:59 ` Hugo Mills
2021-03-10 8:09 ` Ulli Horlacher
2021-03-10 9:35 ` Graham Cobb [this message]
2021-03-10 15:55 ` Ulli Horlacher
2021-03-10 17:29 ` Forza
2021-03-10 17:46 ` Ulli Horlacher
2021-03-10 8:17 ` Ulli Horlacher
2021-03-11 7:46 ` Ulli Horlacher
2021-07-08 22:17 ` cannot use btrfs for nfs server Ulli Horlacher
2021-07-09 0:05 ` Graham Cobb
2021-07-09 4:05 ` NeilBrown
2021-07-09 6:53 ` Ulli Horlacher
2021-07-09 7:23 ` Forza
2021-07-09 7:24 ` Hugo Mills
2021-07-09 7:34 ` Ulli Horlacher
2021-07-09 16:30 ` Chris Murphy
2021-07-10 6:35 ` Ulli Horlacher
2021-07-11 11:41 ` Forza
2021-07-12 7:17 ` Ulli Horlacher
2021-07-09 16:35 ` Chris Murphy
2021-07-10 6:56 ` Ulli Horlacher
2021-07-10 22:17 ` Chris Murphy
2021-07-12 7:25 ` Ulli Horlacher
2021-07-12 13:06 ` Graham Cobb
2021-07-12 16:16 ` Ulli Horlacher
2021-07-12 22:56 ` g.btrfs
2021-07-13 7:37 ` Ulli Horlacher
2021-07-19 12:06 ` Forza
2021-07-19 13:07 ` Forza
2021-07-19 13:35 ` Forza
2021-07-27 11:27 ` Ulli Horlacher
2021-07-09 16:06 ` Lord Vader
2021-07-10 7:03 ` Ulli Horlacher
[not found] ` <162632387205.13764.6196748476850020429@noble.neil.brown.name>
2021-07-15 14:09 ` [PATCH/RFC] NFSD: handle BTRFS subvolumes better Josef Bacik
2021-07-15 16:45 ` Christoph Hellwig
2021-07-15 17:11 ` Josef Bacik
2021-07-15 17:24 ` Christoph Hellwig
2021-07-15 18:01 ` Josef Bacik
2021-07-15 22:37 ` NeilBrown
2021-07-19 15:40 ` Josef Bacik
2021-07-19 20:00 ` J. Bruce Fields
2021-07-19 20:44 ` Josef Bacik
2021-07-19 23:53 ` NeilBrown
2021-07-19 15:49 ` J. Bruce Fields
2021-07-20 0:02 ` NeilBrown
2021-07-19 9:16 ` Christoph Hellwig
2021-07-19 23:54 ` NeilBrown
2021-07-20 6:23 ` Christoph Hellwig
2021-07-20 7:17 ` NeilBrown
2021-07-20 8:00 ` Christoph Hellwig
2021-07-20 23:11 ` NeilBrown
2021-07-20 22:10 ` J. Bruce Fields
2021-07-15 23:02 ` NeilBrown
2021-07-15 15:45 ` J. Bruce Fields
2021-07-15 23:08 ` NeilBrown
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