Tr : NFSv4 idmapd memory consumption problem

[J. Bruce Fields]

On Thu, Aug 31, 2006 at 08:40:51AM +0200, pierre_stephane.baton at alcatelaleniaspace.com wrote:
> I have a little problem with NFSv4 : The NFSv4 ID <-> Name Mapper daemon 
> (rpc.idmapd) uses lots of memory but I don't use nfsv4 mounts, only simple 
> nfs mounts : 

If you're making no use of nfsv4, then you can safely just kill
rpc.idmapd.

But this suggests a nasty memory leak that it'd be useful to understand:

> This is the rpc.idmapd memory usage (8 Go installed) :
> 
> PID     USER    PR      NI      VIRT    RES     SHR     S       %CPU %MEM 
> TIME+   COMMAND
> 1825    root    16      0       2075m   1.1g    868     S       0.0     
> 14.2    2:08.36 rpc.idmapd

You're running autofs?  So there could be lots of mounts and unmounts?

Every such mount/unmount creates one of these virtual directories:

> There's a lot of directories in  /var/lib/nfs/rpc_pipefs :

and rpc.idmapd does try to track changes to this list of directories,
even if it's not doing anything else.  So there must be some leak in the
code that does that, either in rpc.idmapd or libevent.

--b.