Documentation #11503
closed
Added by Peter Matulis about 9 years ago.
Updated almost 9 years ago.
Description
The top of the PG page [1] is completely wrong.
a) You do not create a pool in this way:
ceph osd pool set {pool-name} pg_num
But you do set the number of PGs for a pool in this way:
ceph osd pool set {pool-name} pg_num {pg_num}
b) PG numbers are limited by 32 per OSD
For instance, "Between 5 and 10 OSDs set pg_num to 512". This will not work. The maximum PGs I can set for 10 OSDs is 320.
[1]: http://ceph.com/docs/master/rados/operations/placement-groups/
- Assignee set to Kefu Chai
Peter Matulis wrote:
The top of the PG page [1] is completely wrong.
b) PG numbers are limited by 32 per OSD
For instance, "Between 5 and 10 OSDs set pg_num to 512". This will not work. The maximum PGs I can set for 10 OSDs is 320.
Peter, i am able to set 1024 for a 3-OSD cluster created using vstart.sh script. by inspecting the code, we have a setting named "mon_max_pool_pg_num" which control the maximum number for a pool. but this # is not associated with the # of OSD. following is how i create a 1024-pg pool with my little cluster.
$ ./ceph osd pool create cache_pool4 1024
*** DEVELOPER MODE: setting PATH, PYTHONPATH and LD_LIBRARY_PATH ***
pool 'cache_pool4' created
$ ./ceph osd pool get cache_pool4 all
*** DEVELOPER MODE: setting PATH, PYTHONPATH and LD_LIBRARY_PATH ***
size: 3
min_size: 1
crash_replay_interval: 0
pg_num: 1024
pgp_num: 1024
crush_ruleset: 0
auid: 0
write_fadvise_dontneed: false
$ ./ceph osd ls
*** DEVELOPER MODE: setting PATH, PYTHONPATH and LD_LIBRARY_PATH ***
0
1
2
[1]: http://ceph.com/docs/master/rados/operations/placement-groups/
- Status changed from New to Resolved
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