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,