Hope to get it installed this weekend. Ray On Fri, Mar 30, 2012 at 01:33:10PM -0700, Aaron Blew wrote: > UPDATE > > I rolled a new kernel that's identical to the stock CentOS 2.6.32-220.el6 > kernel with the exception of the new idmapper being enabled. Unfortunately > there's been no improvement. > > Did you get a chance to try the RHEL kernel? > > -Aaron > > > On Fri, Mar 16, 2012 at 7:01 PM, Ray Van Dolson <rayvd at bludgeon.org> wrote: > > > On Fri, Mar 16, 2012 at 01:33:54PM -0700, Aaron Blew wrote: > > > Hello all, > > > I'm currently experiencing an issue with an NFS server I've built (a Dell > > > R710 with a Dell PERC H800/LSI 2108 and four external disk trays). It's > > a > > > backup target for Solaris 10, CentOS 5.5 and CentOS 6.2 servers that > > mount > > > it's data volume via NFS. It has two 10gig NICs set up in a layer2+3 > > bond > > > for one network, and two more 10gig NICs set up in the same way in > > another > > > network. The host has a 99T XFS filesystem for the backups. > > RPCNFSDCOUNT > > > is set to 256. > > > > > > During backups from clients the system exhibits odd hangs that interfere > > > with some of our sensitive system's backup windows. On the NFS server > > side > > > we see the following in dmesg. Originally I thought it was related to > > > dirty writeback cache, but I adjusted dirty_writeback_centisecs and am > > > still seeing the issue. > > > > > > dmesg during the problem window: > > > Mar 16 07:01:21 *****store01 kernel: __ratelimit: 11 callbacks suppressed > > > Mar 16 07:01:21 *****store01 kernel: nfsd: page allocation failure. > > > > <snip> > > > > > > > > Has anyone else seem similar issues? I can provide additional details > > > about the server/configuration if anybody needs anything else. The issue > > > only seems to occur under high write load as we've restored some of these > > > backups and didn't seem to have an issue reading the data. > > > > The page allocation failure message made me wonder if your issue could > > be related to the issue I've run into here[1] on RHEL 6.2. > > > > My issue seems to be related to NFS mounting, but it's possible the > > root cause could be the same? > > > > A few other links: > > > > https://bugzilla.redhat.com/show_bug.cgi?id=593035 > > http://www.spinics.net/lists/linux-nfs/msg22248.html > > > > Red Hat has provided me with a test kernel which purportedly will > > resolve the issue. I haven't had a chance to test it out yet. > > > > Ray > > > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=751992