nfs_getpages: error 4

[Dmitry Sivachenko]

> On 05 Mar 2016, at 15:13, Eugene Grosbein <eugen at grosbein.net> wrote:
> 
> 05.03.2016 18:21, Dmitry Sivachenko пишет:
>> Hello,
>> 
>> 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)