27 Jan
2020
27 Jan
'20
2:40 p.m.
I have a Ceph Luminous (12.2.12) cluster with 6 nodes. I'm attempting to create an
EC3+2 pool with the following commands:
1. Create the EC profile:
* ceph osd erasure-code-profile set es32 k=3 m=2 plugin=jerasure w=8
technique=reed_sol_van crush-failure-domain=host crush-root=sgshared
2. Verify profile creation:
[root@mon-1 ~]# ceph osd erasure-code-profile get es32
crush-device-class=
crush-failure-domain=host
crush-root=sgshared
jerasure-per-chunk-alignment=false
k=3
m=2
plugin=jerasure
technique=reed_sol_van
w=8
1. Create a pool using this profile:
* ceph osd pool create ec32pool 1024 1024 erasure es32
2. List pool detail:
* pool 31 'es32' erasure size 5 min_size 4 crush_rule 11 object_hash
rjenkins pg_num 1024 pgp_num 1024 last_change 1568 flags hashpspool stripe_width 12288
application ES
3. Here's the crush rule that's created:
{
"rule_id": 11,
"rule_name": "es32",
"ruleset": 11,
"type": 3,
"min_size": 3,
"max_size": 5,
"steps": [
{
"op": "set_chooseleaf_tries",
"num": 5
},
{
"op": "set_choose_tries",
"num": 100
},
{
"op": "take",
"item": -2,
"item_name": "sgshared"
},
{
"op": "chooseleaf_indep",
"num": 0,
"type": "host"
},
{
"op": "emit"
}
]
},
From the output of "ceph osd pool ls detail" you can see min_size=4, the crush
rule says min_size=3 however the pool does NOT survive 2 hosts failing.
Am I missing something?