Does zfs have it's own nfs server?

[jhell]

On Fri, 19 Mar 2010 20:18, Jeremy Chadwick wrote:
In Message-Id: <20100320001820.GA92920 at icarus.home.lan>

> On Fri, Mar 19, 2010 at 07:50:24PM -0400, Charles Sprickman wrote:
>> On Fri, 19 Mar 2010, Willem Jan Withagen wrote:
>>
>>> On 17-3-2010 9:27, Matthias Gamsjager wrote:
>>>> sharenfs does work in freebsd but iscsi does not. I'm not sure about smb.
>>>>
>>>> about nfs: you should take a look at /etc/zfs/exports
>>>>
>>>>
>>>>
>>>> On Wed, Mar 17, 2010 at 9:15 AM, Harald Schmalzbauer
>>>> <h.schmalzbauer at omnilan.de>  wrote:
>>>>> Hello,
>>>>>
>>>>> I observed some very strange filesystem security problems.
>>>>> Now I found that if I set sharenfs=yes data/pub I can mount_nfs but it
>>>>> does't respect any settings in /etc/exports. Also I get very strange uid
>>>>> numbers when writing.
>>>>> If I turn sharenfs off, limitations in /etc/exports work as expected.
>>>>> I thought sharenfs and sharesmb are only working on
>>>>> OpenSolaris. What about
>>>>> shareiscsi?
>>>
>>> I do not use /etc/exports for zfs shares....
>>> But instead of yes as value, you can use the NFS-options as string
>>> and that gets it into /etc/zfs/exports.
>>
>> Just wondering, is this using the base nfsd/mountd, or is there some
>> in-kernel nfs code strictly for zfs?  I haven't found much info on
>> the share* options in the manpage or wiki.
>
> ZFS on FreeBSD's "sharenfs" option does nothing more than manage data in
> a flat file (/etc/zfs/exports) and automatically send a SIGHUP to
> mountd's pid (based on reading the contents of the file
> _PATH_MOUNTDPID).  If you grep through /usr/src/cddl you can see what
> I'm referring to.
>
> "So how does mountd know about /etc/zfs/exports?"
>
> $ ps -auxw | grep mount
> root      861  0.0  0.0  6836  1716  ??  Is   10Mar10   0:00.00 /usr/sbin/mountd -r -l /etc/exports /etc/zfs/exports
>
> This is defined/referenced in /etc/rc.d/mountd.
>
> All that said:
>
> I avoid use of the "sharenfs" option in ZFS on RELENG_7 and RELENG_8, as
> I found certain quirks/behavioural oddities (such as mountd not picking
> up changes, or claims of not exporting something which visually
> confirmed should have been exported -- and in one case, mounting of a
> ZFS-exported NFS filesystem worked but then any I/O would block on the
> client indefinitely.  Don't ask me how/why that happened).  Possibly
> these were bugs that existed during ZFS's transitional phase between 7.x
> and 8.x, but the unreliable nature of the situation left a bad taste in
> my mouth.  The workaround:
>
> Using /etc/exports to reference the local ZFS filesystems I want
> exported, HUP mountd, done.  Above oddities/quirks no longer happened.
> And there's an added bonus: all your exports are therefore kept in one
> single place: a text file that's existed since what, 1989 or so?
>
> Of course, the advantage is that with ZFS properties you can inherit
> options -- that might be useful to some, but not to me.
>
> There's also known quirks/issues with the parsing logic with "sharenfs".
> This was discussed in December 2009.
>
>> Could you give an example of passing options that would say, limit
>> to a subnet and map root to root using the zfs sharenfs command?
>
> zfs create pool/fs
> zfs set sharenfs="-maproot=blah -network x.x.x.x -mask y.y.y.y" pool/fs
>
> Right now I'm more or less "avoiding" NFS as much as possible, as the
> number of severe/major bug reports on RELENG_8 keep coming in, and that
> scares me greatly.
>
>


There is also this:

http://www.freebsd.org/cgi/query-pr.cgi?pr=144447

Which I filed a while back that shows a bug in at least stable/7 that does 
not unshare/remove shared filesystems from /etc/zfs/exports.

PJD has taken this PR and asked for a followup if this can be confirmed on 
a 8.X system as he believes it is fixed there.

If someone of this thread is running a 8.X system would you please 
followup to this PR with YES/NO it exists or not, and it would be greatly 
appreciated.

I believe this also has a part of sending HUP to mountd but I could not 
test that either on stable/7 or stable/8.

-- 

  jhell