To display how many PGs in each OSD of a Ceph cluster:
$ ceph --format xml pg dump | \
xmlstarlet sel -t -m "//pg_stats/pg_stat/acting" -v osd -n | \
sort -n | uniq -c
332 0
312 1
299 2
326 3
291 4
295 5
316 6
311 7
301 8
313 9
Where xmlstarlet loops over each PG acting set ( -m “//pg_stats/pg_stat/acting” ) and displays the OSDs it contains (-v osd), one by line (-n). The first column is the number of PGs in which the OSD in the second column shows.
To restrict the display to the PGs belonging to a given pool:
ceph --format xml pg dump | \ xmlstarlet sel -t -m "//pg_stats/pg_stat[starts-with(pgid,'0.')]/acting" -v osd -n | \ sort -n | uniq -c
Where 0. is the prefix of each PG that belongs to pool 0.
Salut Loïc,
Did you try to run the same command but instead of the whole cluster on pool basis?
Would be nice to check the distribution for certain pool too ;-).
Thanks!
I updated the post with an example to restrict the display to a given pool.
Merci !