From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kip Macy Subject: Re: xenolinux /dev/random Date: Fri, 14 May 2004 06:57:13 -0700 (PDT) Sender: xen-devel-admin@lists.sourceforge.net Message-ID: <20040514065606.N77678@demos.bsdclusters.com> References: <20040513075236.B20816@demos.bsdclusters.com> <20040514014250.GA9904@pathfinder> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <20040514014250.GA9904@pathfinder> Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Steve Traugott Cc: Steven Hand , Ian Pratt , xen-devel@lists.sourceforge.net, joyce@terraluna.org, awclarke@tstt.net.tt List-Id: xen-devel@lists.xenproject.org > > Right now the only reason I'm even using NFS is because a Xenoserver > provider needs to be able to do backups, migration, failover, and so on. > How are other people meeting these requirements? Has the CoW > development stalled? What about live migration? I think iSCSI is the way to go. However, I don't know of any good open source iSCSI targets. -Kip > > Steve > > On Thu, May 13, 2004 at 07:54:57AM -0700, Kip Macy wrote: > > Are you also using Linux as an NFS server? We use Linux extensively > > in-house for client machines and have not seen this. Although I'm sure > > we don't use the default Linux settings. > > > > > > -Kip > > > > > > On Thu, 13 May 2004, Steven Hand wrote: > > > > > > > > >My goodness! See the message I just now posted to xen-devel about NFS > > > >root hangs; could this be what we're hitting? The most recent hang we > > > >saw happened while an rsync was running over ssh *and* someone restarted > > > >apache... > > > > > > > >This wouldn't cause the "NFS server not responding/NFS server OK" > > > >messages on the domain's console, though (or does that show up as a > > > >symptom of this too?) > > > > > > I don't think this is the cause of the NFS hangs you've been seeing; that > > > appears to be a generic linux thing (at least we see it with our regular > > > linux boxes as well as with xen boxes); however if you want to test the > > > theory the easiest thing to do is to change the /dev/random device node > > > to be an alias for /dev/urandom (a non-blocking but potentiallyweaker > > > source of randomness). > > > > > > The /dev/random bug only really manifested for us during boot, only on > > > Xen, and resulted in a permanenent hang. > > > > > > The "NFS server foo not responding" followed by later "NFS server foo OK" > > > messages from linux appear to be due to a combination of stupid timeouts > > > in the linux sunrpc code and another bug which can cause automounters > > > to fall into an uninterruptible sleep. If you check "ps auwwx" on a > > > machine which is having problems and notice proceesses in state 'D' > > > then this is biting you. Even if this doesn't occur, the crappy timeouts > > > in the regular linux code mean that linux perfroms very badly if it gets > > > any errors/loss/congestion during nfs operations. > > > > > > cheers, > > > > > > S. > > > > > > > > > ------------------------------------------------------- > > > This SF.Net email is sponsored by: SourceForge.net Broadband > > > Sign-up now for SourceForge Broadband and get the fastest > > > 6.0/768 connection for only $19.95/mo for the first 3 months! > > > http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click > > > _______________________________________________ > > > Xen-devel mailing list > > > Xen-devel@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/xen-devel > > > > > > > > > ------------------------------------------------------- > > This SF.Net email is sponsored by: SourceForge.net Broadband > > Sign-up now for SourceForge Broadband and get the fastest > > 6.0/768 connection for only $19.95/mo for the first 3 months! > > http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/xen-devel > > -- > Stephen G. Traugott (KG6HDQ) > UNIX/Linux Infrastructure Architect, TerraLuna LLC > stevegt@TerraLuna.Org > http://www.stevegt.com -- http://Infrastructures.Org > > > ------------------------------------------------------- > This SF.Net email is sponsored by: SourceForge.net Broadband > Sign-up now for SourceForge Broadband and get the fastest > 6.0/768 connection for only $19.95/mo for the first 3 months! > http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/xen-devel > ------------------------------------------------------- This SF.Net email is sponsored by: SourceForge.net Broadband Sign-up now for SourceForge Broadband and get the fastest 6.0/768 connection for only $19.95/mo for the first 3 months! http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click