Poor NFSv4 first impressions

Poor NFSv4 first impressions

[Jeff Garzik]

Being a big user of NFS at home, and a big fan of NFSv4, it was high 
time that I converted my home network from NFSv3 to NFSv4.

Unfortunately applications started breaking left and right.  vim 
noticeably malfunctioned, trying repeatedly to create a swapfile (sorta 
like a lockfile).  Mozilla Thunderbird would crash reproducibly whenever 
it tried anything remotely major with a mailbox, such as compressing 
folders (removing deleted messages).

Both NFSv4 server and NFSv4 client were x86-64 Linux boxes, running 
hyper-recent kernel 2.6.19-rc4-g10b1fbdb 
(10b1fbdb0a0ca91847a534ad26d0bc250c25b74f).  FC5 userland on the server, 
FC6 userland on the client.  There were no other clients connected to 
the NFS server, much less using my NFS homedir.  This data was not being 
accessed on the server directly, either.

/etc/exports contains:
/g 
10.10.10.0/255.255.255.0(rw,fsid=0,insecure,no_subtree_check,no_root_squash)

NFSv4 /etc/fstab line:
pretzel:/       /g      nfs4    defaults,proto=tcp,hard,intr    0 0

NFSv3 (previous) /etc/fstab line for same file server:
pretzel:/g              /g              nfs     defaults,tcp    0 0


I hope this is just a temporary problem, but as it looks right now, 
NFSv4 isn't ready for prime time, with all these apps breaking :/

	Jeff

Re: Poor NFSv4 first impressions

[Daniel J Blueman]

Jeff Garzik wrote:
> Being a big user of NFS at home, and a big fan of NFSv4, it was high
> time that I converted my home network from NFSv3 to NFSv4.
>
> Unfortunately applications started breaking left and right.  vim
> noticeably malfunctioned, trying repeatedly to create a swapfile (sorta
> like a lockfile).  Mozilla Thunderbird would crash reproducibly whenever
> it tried anything remotely major with a mailbox, such as compressing
> folders (removing deleted messages).
[snip]

This has all the symptoms to an open EACCES NFSv4 bug in 2.6.18/19.
This is fixed in:

http://www.citi.umich.edu/projects/nfsv4/linux/kernel-patches/2.6.19-rc3-2/linux-2.6.19-rc3-CITI_NFS4_ALL-2.diff
(see http://www.citi.umich.edu/projects/nfsv4/linux/).

With this patch, I can run just great with NFSv4 home dir (etc)
mounts; without, I get the symptom of many 0-byte temporary/lock files
being created and often the inability to create files (!). Be sure to
allow callback delegation connections in through your firewall for the
extra performance ;-) .

Maybe it's too late for these fixes 2.6.19, but they should certainly
make 2.6.19.1 IMHO.
-- 
Daniel J Blueman

Re: Poor NFSv4 first impressions

[Bill Davidsen]

Daniel J Blueman wrote:
> Jeff Garzik wrote:
>> Being a big user of NFS at home, and a big fan of NFSv4, it was high
>> time that I converted my home network from NFSv3 to NFSv4.
>>
>> Unfortunately applications started breaking left and right.  vim
>> noticeably malfunctioned, trying repeatedly to create a swapfile (sorta
>> like a lockfile).  Mozilla Thunderbird would crash reproducibly whenever
>> it tried anything remotely major with a mailbox, such as compressing
>> folders (removing deleted messages).
> [snip]
> 
> This has all the symptoms to an open EACCES NFSv4 bug in 2.6.18/19.
> This is fixed in:
> 
> http://www.citi.umich.edu/projects/nfsv4/linux/kernel-patches/2.6.19-rc3-2/linux-2.6.19-rc3-CITI_NFS4_ALL-2.diff 
> 
> (see http://www.citi.umich.edu/projects/nfsv4/linux/).
> 
> With this patch, I can run just great with NFSv4 home dir (etc)
> mounts; without, I get the symptom of many 0-byte temporary/lock files
> being created and often the inability to create files (!). Be sure to
> allow callback delegation connections in through your firewall for the
> extra performance ;-) .
> 
> Maybe it's too late for these fixes 2.6.19, but they should certainly
> make 2.6.19.1 IMHO.

If NFSv4 really works that poorly without the patches, perhaps they 
should go in 2.6.19 at the start. I'm surprised others aren't having 
this problem, I thought there was more test use.


-- 
Bill Davidsen <davidsen@tmr.com>
   Obscure bug of 2004: BASH BUFFER OVERFLOW - if bash is being run by a
normal user and is setuid root, with the "vi" line edit mode selected,
and the character set is "big5," an off-by-one errors occurs during
wildcard (glob) expansion.

Re: Poor NFSv4 first impressions

[J. Bruce Fields]

On Mon, Nov 06, 2006 at 12:03:54PM +0000, Daniel J Blueman wrote:
> This has all the symptoms to an open EACCES NFSv4 bug in 2.6.18/19.
> This is fixed in:
> 
> http://www.citi.umich.edu/projects/nfsv4/linux/kernel-patches/2.6.19-rc3-2/linux-2.6.19-rc3-CITI_NFS4_ALL-2.diff
> (see http://www.citi.umich.edu/projects/nfsv4/linux/).
> 
> With this patch, I can run just great with NFSv4 home dir (etc)
> mounts; without, I get the symptom of many 0-byte temporary/lock files
> being created and often the inability to create files (!). Be sure to
> allow callback delegation connections in through your firewall for the
> extra performance ;-) .
> 
> Maybe it's too late for these fixes 2.6.19, but they should certainly
> make 2.6.19.1 IMHO.

Yeah, bad patch management on my part, apologies, I should have pushed
it as soon as I noticed the problem.

Investigating the problem revealed some ugliness (and some races which
will need further work), and I had hoped to have a more complete fix
before now.  Oh well.

Two patches follow; the first does a very simple cleanup, the second
solves the immediate problem in the most straightforward way I can see,
but is a bit of a hack.

--b.

Re: Poor NFSv4 first impressions

[Pavel Machek]

> With this patch, I can run just great with NFSv4 home dir (etc)
> mounts; without, I get the symptom of many 0-byte temporary/lock files
> being created and often the inability to create files (!). Be sure to
> allow callback delegation connections in through your firewall for the
> extra performance ;-) .
> 
> Maybe it's too late for these fixes 2.6.19, but they should certainly
> make 2.6.19.1 IMHO.

If they are good enough for 2.6.19.1, they should _definitely_ go into
2.6.19.


								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html