11 Mar
2020
11 Mar
'20
11:23 a.m.
Hi all,
I am trying to setup an active-active NFS Ganesha cluster (with two Ganeshas (v3.0)
running in Docker containers). I could manage to get two Ganesha daemons running using the
rados_cluster backend for active-active deployment. I have the grace db within the cephfs
metadata pool in an own namespace which keeps track on the node status.
Now, I can mount the exposed filesystem over NFS (v4.1, v4.2) with both daemons. So far so
good. __
Testing high availability resulted in an unexpected behavior for that I am not sure
whether it is intentional or whether it is a configuration problem.
Problem:
If both are running, no E or N flags are set within the grace db, as I expect. Once, one
host goes down (or is taken down) ALL clients cannot read nor write to the mounted
filesystem, even the clients which are not connected to dead ganesha. In the db, I see
that the dead ganesha has state NE and the active has E. This state is what I expect from
the Ganesha documentation. Nevertheless, I would assume that the clients connected to the
active daemon are not blocked. This state is not cleaned up by itself (e.g. after the
grace period).
I can unlock this situation by 'lifting' the dead node with a direct db call
(using ganesha-rados-grace tool). But within an active-active deployment this is not
suitable.
The ganesha config looks like:
------------
NFS_CORE_PARAM
{
Enable_NLM = false;
Protocols = 4;
}
NFSv4
{
RecoveryBackend = rados_cluster;
Minor_Versions = 1,2;
}
RADOS_KV
{
pool = "cephfsmetadata";
nodeid = "a" ;
namespace = "grace";
UserId = "ganesha";
Ceph_Conf = "/etc/ceph/ceph.conf";
}
MDCACHE {
Dir_Chunk = 0;
NParts = 1;
Cache_Size = 1;
}
EXPORT
{
Export_ID=101;
Protocols = 4;
Transports = TCP;
Path = PATH;
Pseudo = PSEUDO_PATH;
Access_Type = RW;
Attr_Expiration_Time = 0;
Squash = no_root_squash;
FSAL {
Name = CEPH;
User_Id = "ganesha";
Secret_Access_Key = CEPHXKEY;
}
}
LOG {
Default_Log_Level = "FULL_DEBUG";
}
------------
Does anyone have similar problems? Or if this behavior is by purpose, can you explain to
me why this is the case?
Thank you in advance for your time and thoughts.
Kind regards,
Michael