[ceph-users] Re: MDS: cache pressure warnings with Ganesha exports

9 Apr 2020


      On Tue, 2020-04-07 at 07:34 +0000, Stolte, Felix wrote:
...
Hey folks,
I  keep getting ceph health warnings about clients failing to respond to cache pressure. They always refer to sessions from ganesha exports. I've read all threads regarding this issue, but none of my changes resolved it. What I’ve done so far:
Ganesha.conf:
MDCACHE {
    Dir_Chunk = 0;
    NParts = 1;
    Cache_Size = 1;
}
Attr_Expiration_Time = 0 in every export
mds_cache_memory_limit = 17179869184 on MDS Servers
I even set “client_oc = false” on the ganesha server, but this doesn’t seem to be applied
My setup is ceph version 14.2.8 (All Server and clients. One active MDS. Ganesha 2.8.3 runs on a dedicated Server.
ceph daemon mds.<active_mds> dump_mempools (filtered out the empty pools):
"mempool": {
        "by_pool": {
            "bloom_filter": {
                "items": 1414723,
                "bytes": 1414723
            },
            "buffer_anon": {
                "items": 180992,
                "bytes": 2404306271
            },
            "buffer_meta": {
                "items": 178660,
                "bytes": 15722080
            },
            "osdmap": {
                "items": 4121,
                "bytes": 75912
            },   
      "mds_co": {
                "items": 221728924,
                "bytes": 16320868177
            },
        },
        "total": {
            "items": 223507420,
            "bytes": 18742387163
Every hint how to resolve the issue are welcome. If more information is needed, I am glad to provide it.
You may want to follow the suggestion here and see if it helps:

    https://tracker.ceph.com/issues/44976#note-23

-- 
Jeff Layton <jlayton@redhat.com>