Hi All
I upgraded my 12.2.0 cluster to 12.2.1 a month or two back. I've noticed that the number of inodes held in cache is only approx 1/5th of my inode_max. This is a surprise to me as with 12.2.0, and before that Jewel, after starting an MDS server, the cache would typically fill to the max within 24 hours. I have ~8 million entries my file system, and most of this is fairly hot data. I'm seeing quite frequent "failing to respond to cache pressure" messages, I just have two Kernel clients accessing the filesystem.
Are there some new defaults I need to change perhaps? Or potentially a bug?
Output of perf dump mds:
"mds": {"request": 184132091,"reply": 184132064,"reply_latency": {"avgcount": 184132064,"sum": 125364.905594355,"avgtime": 0.000680842},"forward": 0,"dir_fetch": 9846671,"dir_commit": 562495,"dir_split": 0,"dir_merge": 0,"inode_max": 2500000,"inodes": 444642,"inodes_top": 185845,"inodes_bottom": 127878,"inodes_pin_tail": 130919,"inodes_pinned": 179149,"inodes_expired": 135604208,"inodes_with_caps": 165900,"caps": 165948,"subtrees": 2,"traverse": 187280168,"traverse_hit": 185739606,"traverse_forward": 0,"traverse_discover": 0,"traverse_dir_fetch": 118150,"traverse_remote_ino": 8,"traverse_lock": 60256,"load_cent": 18413221445,"q": 0,"exported": 0,"exported_inodes": 0,"imported": 0,"imported_inodes": 0}
A few extra details:
Running two MDS servers, one is standby.
Both have mds_cache_size = 2500000.
CentOS 7.3 servers.
Kernel clients are CentOS 7.3 (3.10.0-514.2.2.el7.x86_64)
Thanks,
David
_______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
