Kefu, can you please look into this issue (or re-assign as appropriate?)

as Sam put, it's not entirely a bug. see http://docs.ceph.com/docs/master/rados/operations/crush-map/#crush-map-rules. but we can surely detect the ambiguous case where CRUSH could choose multiple rules from a given ruleset for a given pool.

but i'd like put this feature into crushtool:

$ crushtool --check -i <crush_file>

overlapped rules: replicated_rule0, replicated_rule1
overlapped rules: replicated_rule0, replicated_rule2

if we feed following rules to crushtool:

rule replicated_rule0 {
        ruleset 0
        type replicated
        min_size 1
        max_size 3
        step take default
        step chooseleaf firstn 0 type osd
        step emit
}

rule replicated_rule1 {
        ruleset 0
        type replicated
        min_size 1
        max_size 1
        step take default
        step chooseleaf firstn 0 type host
        step emit
}

rule replicated_rule2 {
        ruleset 0
        type replicated
        min_size 2
        max_size 3
        step take default
        step chooseleaf firstn 0 type host
        step emit
}


what do you think?

Looks good.

https://github.com/ceph/ceph/pull/7139

https://github.com/ceph/ceph/pull/7139 accepted upstream

Bara, i updated the "Doc Text" with some sample output if any rules are overlapped. does it make sense to you?

Verified with - 10.2.1-12.el7cp.x86_64



[root@magna051 ubuntu]# crushtool -i  "/tmp/cm.new" --check
overlapped rules in ruleset 0: replicated_rule0, replicated_rule1, replicated_ruleset
overlapped rules in ruleset 0: replicated_rule0, replicated_rule2, replicated_ruleset
[root@magna051 ubuntu]# crushtool -i  "/tmp/cm" --check

Works as expected hence moving to Verified

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2016:1755