Andrew Zahn wrote: > Hi All, > > I am looking for advice on how to cure a constantly-crashing NFS > server which crashes every few hours, or at least, every few days. The > kernel log file (below) points toward NFS as a likely cause. > > The system disk is a 3ware 8000 series RAID1 mirror. The data disk is > using a 3Ware 9000 controller to produce two RAID1 devices; these are > then striped (RAID0) in software to form a RAID 10 device. We're > using a 2.6 kernel, xfs filesystem, and NFS3/UDP. > > We're running CentOS 4.2 with a 2.6.9-22.0.1.106 kernel. This kernel > has xfs extensions, and we're running the xfs filesystem for /home > (obtained from CentOS website). > > In "lsmod" I see both 3w_xxxx and 3w_9xxx modules. > > NFS is over UDP, jumbo frames (9000), 32k rsize/wsize, async server, > async clients, noac. > > This system has been serving /home in this configuration since October > 2005; we've seen it crash rarely, but uptimes were usually on the > order of months. This past week, it can't seem to remain up for much > longer than about a day. > > Kernel log file containing the crash: > > Feb 12 05:52:03 tier2-home kernel: Unable to handle kernel NULL > pointer dereference at virtual address 00000000 > Feb 12 05:52:03 tier2-home kernel: printing eip: > Feb 12 05:52:03 tier2-home kernel: 00000000 > Feb 12 05:52:03 tier2-home kernel: *pde = f561f067 > Feb 12 05:52:03 tier2-home kernel: Oops: 0000 [#1] > Feb 12 05:52:03 tier2-home kernel: PREEMPT SMP > Feb 12 05:52:03 tier2-home kernel: Modules linked in: nfs nfsd > exportfs lockd md5 ipv6 autofs4 i2c_dev i2c_core sunrpc xfs dm_mirror > dm_mod button battery ac uhci_hcd shpchp e100 > 0 floppy ext3 jbd 3w_9xxx 3w_xxxx sd_mod scsi_mod > Feb 12 05:52:03 tier2-home kernel: CPU: 0 <snip> Hmmm...does it also crash if you run a non-SMP kernel? Did you update the kernel around the same time as the instability began? Cheers,