I have moved the pool, but strange thing is that if I do something like this
for object in `cat out`; do rados -p fs_meta get $object /dev/null ; done I do not see any activity on the ssd drives with something like dstat (checked on all nodes (sdh)) net/eth4.60-net/eth4.52 --dsk/sda-----dsk/sdb-----dsk/sdc-----dsk/sdd-----dsk/sde-----dsk/sdf--- --dsk/sdg-----dsk/sdh-----dsk/sdi-- recv send: recv send| read writ: read writ: read writ: read writ: read writ: read writ: read writ: read writ: read writ 0 0 : 0 0 | 415B 201k:3264k 1358k:4708k 3487k:5779k 3046k: 13M 6886k:9055B 487k:1118k 836k: 327k 210k:3497k 1569k 154k 154k: 242k 336k| 0 0 : 0 0 : 0 12k: 0 0 : 0 0 : 0 0 : 0 0 : 0 0 : 0 0 103k 92k: 147k 199k| 0 164k: 0 0 : 0 32k: 0 0 :8192B 12k: 0 0 : 0 0 : 0 0 : 0 0 96k 124k: 108k 96k| 0 4096B: 0 0 :4096B 20k: 0 0 :4096B 12k: 0 8192B: 0 0 : 0 0 : 0 0 175k 375k: 330k 266k| 0 69k: 0 0 : 0 0 : 0 0 : 0 0 :8192B 136k: 0 0 : 0 0 : 0 0 133k 102k: 124k 103k| 0 0 : 0 0 : 0 76k: 0 0 : 0 32k: 0 0 : 0 0 : 0 0 : 0 0 350k 185k: 318k 1721k| 0 57k: 0 0 : 0 16k: 0 0 : 0 36k:1416k 0 : 0 0 : 0 144k: 0 0 206k 135k: 164k 797k| 0 0 : 0 0 :8192B 44k: 0 0 : 0 28k: 660k 0 : 0 0 :4096B 260k: 0 0 138k 136k: 252k 273k| 0 51k: 0 0 :4096B 16k: 0 0 : 0 0 : 0 0 : 0 0 : 0 0 : 0 0 158k 117k: 436k 369k| 0 0 : 0 0 : 0 0 : 0 20k: 0 0 :4096B 20k: 0 20k: 0 0 : 0 0 146k 106k: 327k 988k| 0 63k: 0 16k: 0 52k: 0 0 : 0 0 : 0 52k: 0 0 : 0 0 : 0 0 77k 74k: 361k 145k| 0 0 : 0 0 : 0 16k: 0 0 : 0 0 : 0 0 : 0 0 : 0 0 : 0 0 186k 149k: 417k 824k| 0 51k: 0 0 : 0 28k: 0 0 : 0 28k: 0 0 : 0 0 : 0 36k: 0 0 But this showed some activity [@c01 ~]# ceph osd pool stats | grep fs_meta -A 2 pool fs_meta id 19 client io 0 B/s rd, 17 op/s rd, 0 op/s wr I took maybe around 20h to move the fs_meta pool (only 200MB, 2483328 objects) from hdd to ssd, also maybe because of some other remapping of one replaced and one added hdd. (I have slow hdd's) I did not manage to do a good test, because the results seem to be similar as before the move. I did not want to create files because I thought it would include the fs_data pool to much, which is on my slow hdd's. So I did the readdir and stats tests. I checked if mds.a was active, limited the cache of mds.a to 1000 inodes (I think) with: ceph daemon mds.a config set mds_cache_size 1000 () Flushed caches on the nodes with: free && sync && echo 3 > /proc/sys/vm/drop_caches && free And ran these tests: python ../smallfile-master/smallfile_cli.py --operation stat --threads 1 --file-size 128 --files-per-dir 50000 --files 500000 --top /home/backup/test/kernel/ python ../smallfile-master/smallfile_cli.py --operation readdir --threads 1 --file-size 128 --files-per-dir 50000 --files 500000 --top /home/backup/test/kernel/ Maybe this is helpful in selecting a better test for your move. -----Original Message----- From: David C [mailto:dcsysengin...@gmail.com] Sent: maandag 30 juli 2018 14:23 To: Marc Roos Cc: ceph-users Subject: Re: [ceph-users] Cephfs meta data pool to ssd and measuring performance difference Something like smallfile perhaps? https://github.com/bengland2/smallfile Or you just time creating/reading lots of files With read benching you would want to ensure you've cleared your mds cache or use a dataset larger than the cache. I'd be interested in seeing your results, I this on the to do list myself. On 25 Jul 2018 15:18, "Marc Roos" <m.r...@f1-outsourcing.eu> wrote: From this thread, I got how to move the meta data pool from the hdd's to the ssd's. https://www.spinics.net/lists/ceph-users/msg39498.html ceph osd pool get fs_meta crush_rule ceph osd pool set fs_meta crush_rule replicated_ruleset_ssd I guess this can be done on a live system? What would be a good test to show the performance difference between the old hdd and the new ssd? _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
