Re: [Xen-devel] xenolinux /dev/random

[Kip Macy <kmacy@xxxxxxxxxxx>]

>
> 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@xxxxxxxxxxxxxxxxxxxxx
> > > 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@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.sourceforge.net/lists/listinfo/xen-devel
>
> --
> Stephen G. Traugott  (KG6HDQ)
> UNIX/Linux Infrastructure Architect, TerraLuna LLC
> stevegt@xxxxxxxxxxxxx
> 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@xxxxxxxxxxxxxxxxxxxxx
> https://lists.sourceforge.net/lists/listinfo/xen-devel
>