nfs_getpages: error 4
eugen at grosbein.net
Sat Mar 5 13:33:59 UTC 2016
05.03.2016 19:32, Dmitry Sivachenko пишет:
>>> I am running a number of machines with /home mounted via nfs (FreeBSD 10.3-PRERELEASE #0 r294799, rw,bg,intr,soft).
>>> Sometimes I get the following messages in syslog:
>>> nfs_getpages: error 4
>>> vm_fault: pager read error, pid NNN (myprog)
>>> After that I see I lot of processes stuck in "pfault" state (these are computational processes which use some files from NFS mount), they use 0% of CPU after that.
>>> On NFS server machine I see nothing strange in logs. procstat -kk for such stuck processes shows:
>>> PID TID COMM TDNAME KSTACK
>>> 85274 102056 myprog - mi_switch+0xbe sleepq_wait+0x3a _sleep+0x287 vm_waitpfault+0x8a vm_fault_hold+0xdd0 vm_fault+0x77 trap_pfault+0x180 trap+0x52c calltrap+0x8
>>> What can be the reason of this?
>> For example, if some processes running on NFS server box modify some files "in-place"
>> and these files are opened by processes running on NFS client, that could be the reason.
>> If so, change this so processes updating such files create new temporary versions of them first
>> and then rename them atomically.
> This should not be the case: users are working only on NFS clients.
> Moreover, the nature of computations is so that each process uses it's own set of files.
> (Forgot to mention in my previous e-mail that these processes can't be stopped even with kill -9)
Make sure you use TCP mounts and TSO is disabled. Try switching between NFSv3/NFSv4 to avoid this bug
and to discover what version is broken. And show full mount command/option set.
More information about the freebsd-stable