On Thu, Sep 17, 2020 at 1:56 PM Marc Boisis <marc.boisis@univ-lr.fr> wrote:
Hi,
I had to map a rbd from an ubuntu Trusty luminous client on an octopus cluster.
client dmesg : feature set mismatch, my 4a042a42 < server's 100004a042a42, missing 1000000000000
I downgrade my osd tunable to bobtail but it still doesn't work
Hi Marc, Right, that's not enough in your case.
ceph osd crush show-tunables { "choose_local_tries": 0, "choose_local_fallback_tries": 0, "choose_total_tries": 50, "chooseleaf_descend_once": 1, "chooseleaf_vary_r": 0, "chooseleaf_stable": 0, "straw_calc_version": 1, "allowed_bucket_algs": 22, "profile": "bobtail", "optimal_tunables": 0, "legacy_tunables": 0, "minimum_required_version": "hammer", "require_feature_tunables": 1, "require_feature_tunables2": 1, "has_v2_rules": 0, "require_feature_tunables3": 0, "has_v3_rules": 0, "has_v4_buckets": 1,
This is the problem. straw2 buckets require CRUSH_V4 feature bit. If you don't want to upgrade the kernel on the client, you would need to convert straw2 buckets to legacy straw buckets by manually editing your CRUSH map. Thanks, Ilya