Linux NFS development
 help / color / mirror / Atom feed
From: Trond Myklebust <Trond.Myklebust@netapp.com>
To: Chakri n <chakriin5@gmail.com>
Cc: nfs@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: NFS on loopback locks up entire system(2.6.23-rc6)?
Date: Fri, 21 Sep 2007 14:14:13 -0400	[thread overview]
Message-ID: <1190398453.6690.12.camel@heimdal.trondhjem.org> (raw)
In-Reply-To: <92cbf19b0709211106n12b1b4ecxc0d415aa097d21b2@mail.gmail.com>

No. The requirement for 'hard' mounts is not that the server be up all
the time. The server can go up and down as it pleases: the client can
happily recover from that.

The requirement is rather that nobody remove it permanently before the
application is done with it, and the partition is unmounted. That is
hardly unreasonable (it is the only way I know of to ensure data
integrity), and it is much less strict than the requirements for local
disks.

Trond

On Fri, 2007-09-21 at 11:06 -0700, Chakri n wrote:
> Isn't this a strict requirement from client side, asking to guarantee
> that a server stays up all the time?
> 
> I have seen many cases, where people go and directly change IP of
> their NFS filers or servers worrying least about the clients using
> them.
> 
> Can we get around with some sort of congestion logic?
> 
> Thanks
> --Chakri
> 
> On 9/21/07, Trond Myklebust <Trond.Myklebust@netapp.com> wrote:
> > On Fri, 2007-09-21 at 09:20 -0700, Chakri n wrote:
> > > Thanks.
> > >
> > > I was using flock (BSD locking) and I think the problem should be
> > > solved if I move my application to use POSIX locks.
> >
> > Yup.
> >
> > > And any option to avoid processes waiting indefinitely to free pages
> > > from NFS requests waiting on unresponsive NFS server?
> >
> > The only solution I know of is to use soft mounts, but that brings
> > another set of problems:
> >      1. most applications don't know how to recover safely from an EIO
> >         error.
> >      2. You lose data.
> >
> > Cheers
> >   Trond
> >

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2005.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
NFS maillist  -  NFS@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs

  reply	other threads:[~2007-09-21 18:14 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-09-21  0:22 NFS on loopback locks up entire system(2.6.23-rc6)? Chakri n
2007-09-21  0:43 ` Trond Myklebust
2007-09-21  3:12   ` Chakri n
2007-09-21 12:47     ` J. Bruce Fields
2007-09-21 14:13     ` Trond Myklebust
2007-09-21 16:20       ` [NFS] " Chakri n
2007-09-21 16:24         ` Trond Myklebust
2007-09-21 18:06           ` Chakri n
2007-09-21 18:14             ` Trond Myklebust [this message]
2007-09-22  6:28               ` Chakri n
2007-10-06  7:35   ` Pavel Machek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1190398453.6690.12.camel@heimdal.trondhjem.org \
    --to=trond.myklebust@netapp.com \
    --cc=chakriin5@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nfs@lists.sourceforge.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox