@cheryl

Converting your exports and mounts to nfs version v4 will probably fix your
issue. I had similar issues and that fixed it for me and others.
Op 3 feb. 2013 18:50 schreef "cheryl" <email address hidden> het
volgende:

> Sorry, I did not know what to do with my report, so I am attaching it
> here since it seems to be the same problem.
>
> I am running desktop Ubuntu 12.04 lts on 4 separate gigabit-networked
> machines, for my full-home media center, with the tuner installed in the
> 'server' (desktop install running NFS server) under mythtv, and 3
> desktop install NFS clients in separate rooms. I had to upgrade the pre-
> existing 'server' (my learning platform) from 11.10 to 12.04 to match
> the clients because mythtv does not interoperate with differing
> versions, and I did not want to downgrade the clients to 11.10, I wanted
> a long term network install that is reliable and low-maintenance.
>
> Now I have terrible network performance. The tuner works fine within the
> 'server', and I can view shows on the server, channel surf, record, play
> back, etc. no problems. Over the NFS network at the desktop clients, the
> media center system is almost completely broken.
>
> If I start viewing a video media file, or listen to ripped audio, or
> i.e. open any media file at all, that is stored on the server, viewing
> on a client over the network, or if I attempt to edit the commercials
> out of shows on a client from over the network within mythtv editor, or
> even open a text file, the client will pause/hang for at least 30
> seconds while 'loading' the file, and then finally it will start
> sequential streaming the media with OK performance on one or maybe two
> clients max - but when using Videolan VLC to view server media files on
> a client,  I had to increase the buffer by 10X (from 3 to 30 seconds of
> standard definition programming, approximately) to avoid long stuttering
> pauses in playback. Within mythtv frontend application at the client
> side, the video editing over the network is abominably slow, needing
> tenths of seconds, to seconds, to minutes, to hours, to completely hung,
> for the editor to respond to each keypress, getting slower all the time
> until it eventually grinds to a halt.
>
> Listing directories, editing files, viewing media, using any of the text
> editors or media players I have installed, all have at least 30 seconds
> of delay on 'opening' (sending a command, either from a terminal window,
> or a nautilus window, or a text editor, or whatever), and the entire
> network slowly grinds to a standstill eventually, with mythtv locked in
> unusable state at the clients, even though it is still working fine on
> the server.
>
> My server is a core 2 duo and so is my main media center client. The
> server is fully populated with 8gig of memory and terabytes of storage,
> and the client is sparsely populated with 2 gig of memory. I realize
> this is underpowered for hdtv media applications but surely a core 2 duo
> should be able to serve at least one standard definition media file at a
> time without any performance issues at all, and should be able to handle
> text editors with its eyes closed. I also have an i7 laptop client with
> 8 gig of memory and a terabyte of storage that suffers from the same
> poor network performance, even after disabling the troublesome Broadcom
> wireless power management, or even after plugging in the 1 gigabit wired
> connection and disabling of wireless.
>
> I have no security at all configured on this network, and root squash is
> turned off so that I can edit or delete files without having to
> synchronize my clients accounts over NIS with Kerberos, which I do not
> even understand how to install let alone set up. I am just learning
> network admin, doing it on my own, slowly. This is by design a really
> primitive, drop-dead simple network install with only a hardware
> firewall protecting it. All transfers are synchronous, meaning there is
> no automounting going on. Everything is hard mounted, so when the
> desktop server hangs, so do all the desktop clients, if they happen to
> be actively running an NFS-supplied media file or etc. It took me months
> to learn how to do the hard mounting of encrypted volumes properly,
> needing to let it time out and retry until the encrypted raid password
> is entered. I did not encrypt the operating system just yet, not until I
> have everything working in the open, and it is starting to look like I
> will have to start over with another distribution entirely because of
> this bug!!
>
> It seems there is an NFS tuning issue because there are some lost
> packets at the client side, and the NFS forums suggest increasing the
> number of threads. I am just now learning to debug and I have a dim
> perspective on these tuning issues at best. I am no Linux guru and have
> not increased the number of threads, because there is no way I could
> even use up the default number of threads with just a single user on
> this network, unless attempting to transcode from multiple machines at
> once and I do not have the disc space to support that just now anyway. I
> do not see any reason why NFS defaults should perform so badly that they
> lock up the system.
>
> So far I have changed nothing on the NFS tuning, and started searching
> for answers in the bug reports, because it seems to me that for my
> pathetically underused hardware there should be no issues whatsoever
> running a simple, hard-mounted, single-user household media center with
> multiple networked clients and no security, even using conservative
> default tuning that ships with NFS, even if I occasionally run out of
> threads once in a blue moon there should be no performance issues
> whatsoever due to NFS. If anything, I would expect performance issues to
> be due to the hardware, but not of this character where things worsen
> over time so that after one day the network freezes.
>
> Now here I find eerily familiar, long-standing bug reports that seem to
> incriminate kernel updates that changed the NFS auto tuning algorithm. I
> felt compelled to write an explanation of my own scenario since it is so
> different from the sophisticated, network-savvy implementations
> mentioned here. I thought perhaps something of importance could be
> learned, even from someone as ignorant as me, just because the
> implementation I am using is so dirt simple, eliminating many potential
> suspects.
>
> I am wondering to myself, does Ubuntu intend to compete with Microsoft
> in the home media center market, or just let Microsoft eat their lunch?
> Or am I supposed to convert my Ubuntu network to run under Windows
> networking via Samba, and just flush NFS down the toilet? I really,
> really want to use NFS! I want the performance and I do not trust
> Windows networking. But it seems that even advanced Ubuntu users have
> been frustrated for over a year because of this bug! Should I change my
> entire network to Red Hat? I am completely unfamiliar with even their
> packaging application, I have no spare cash lying around, and my
> impression of CentOS is that it is highly stripped-down. I would have to
> build up all my proprietary hardware drivers from scratch and there is
> nothing even approaching the level of the Ubuntu support community for
> Red Hat.
>
> Only solution I have found so far is to reboot all clients and server,
> after which NFS recovers temporarily, but still has long delays when
> starting up the streaming, and eventually grinds to a halt again,
> especially when mythtv fills its allocated disc space, after which it is
> a miracle if I can even task-switch out of its media player app in order
> to reboot all the clients and start over. It seems that even 'disc full'
> error messages are subject to the same limitations of this NFS bug,
> whatever it is.
>
> One other thing I noticed is that mp4 transcoding jobs running in
> Handbrake on the clients, that seem to finish properly and close their
> output files, often actually do not finish writing to the server,
> leaving incomplete, corrupted files and requiring a second, third, or
> fourth attempt at transcoding. Also, the 32-bit machine I am using seems
> to have problems with the no-root-squash function -- while write-
> protecting transcoded output, it chowns its transcoded files attributed
> to user 'nobody', even though the other two (64-bit) clients have no
> problem chowning to root via NFS! Apparently, the older and slower the
> hardware, the worse the problems it experiences with NFS.
>
> I apologize for the long, rambling comment on this bug report. I only
> even wrote it to indicate to the folks at Canonical that this NFS
> problem is affecting ordinary Ubuntu desktop users who are attempting
> merely to run the same full-house media center scenario that is being
> advertised on television for DirectTV and cable subscribers, and being
> implemented independently by Windows users familiar with mythtv and
> handbrake. Without a properly functioning NFS, Ubuntu is properly
> crippled.
>
> I am not a programmer or system administrator, just a retired engineer
> with a little bit of hacking experience. A very little bit. After months
> learning to install and use Ubuntu properly, then I had to read
> documentation files and support group forums for a full year to get this
> far with the network setup, and now to find that the operating system I
> chose has a known, long-standing fatal networking flaw that I have been
> battling with all along feels like a big fat stick in the eye. Would
> some kind soul please remove that stick?
>
> Does anyone consider it important or even kind to add warnings to the
> package manager, or even to the Ubuntu download page, so we do not all
> have to stumble across this networking show-stopper on our own? I chose
> Ubuntu for its ease of use and support, but here is a big fat gaping
> network hole that makes it impossible to even achieve Windows Media
> Center level of performance. Adding insult to injury, there is no
> advance warning anywhere about this networking problem.
>
> Thanks for the learning experience, friends, but if this is the level of
> functionality I can expect from Ubuntu going forward, I am going to have
> no choice but to find another distribution that implements NFS
> correctly. I intend to keep increasing the complexity of my network,
> implementing full-network login accounts, printer sharing, etc. etc, and
> no way do I intend to do it all under Samba! Sorry, this is all the
> feedback I can provide on this bug, mainly that it affects me too and
> that it seems basic to NFS and that it is a show-stopper for my intended
> application. thx
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/879334
>
> Title:
>   nfsd from nfs-kernel-server very slow and system load from 25%-100%
>   from nfsd
>
> Status in “linux” package in Ubuntu:
>   Incomplete
> Status in “nfs-utils” package in Ubuntu:
>   Confirmed
> Status in “linux” package in Debian:
>   Incomplete
>
> Bug description:
>   I have a diskless ubuntu 10.10 machine which I boot regularly using
>   pxe-boot from another ubuntu machine where I have the root filesystem
>   of the diskless machine exported over nfs.
>
>   I set it up about a year ago using 10.10. In the mean while the server
>   machine got upgraded to 11.04 and as of yesterday to 11.10.
>
>   After the upgrade to 11.10 the diskless machine is dead slow (most of
>   the times it wont even boot completely) and the load on the server
>   machine is high (25%-100% as shown from top). If in the middle of the
>   diskless computer booting I do a restart of the nfs server, the client
>   computer proceeds with the boot a bit more and then it gets stuck
>   again. I have to restart and nfs-server 3-4 times in order to get the
>   gdm login screen at the client machine
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 11.10
>   Package: nfs-kernel-server 1:1.2.4-1ubuntu2
>   ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
>   Uname: Linux 3.0.0-12-generic i686
>   ApportVersion: 1.23-0ubuntu3
>   Architecture: i386
>   Date: Fri Oct 21 12:53:02 2011
>   ProcEnviron:
>    LANG=en_US.UTF-8
>    SHELL=/bin/bash
>   SourcePackage: nfs-utils
>   UpgradeStatus: Upgraded to oneiric on 2011-10-20 (1 days ago)
>
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>