Ceph » CephFS

Test cases in TestVolumes create subvolumes/groups/snapshots in format `<string>_<random_number>`. Some test cases will verify list commands by creating (say) 3 subvoumes/group/snapshots and expect that those come back while listing. Python's random number generator is not truly random leading to the same number getting repeated (unlucky) which caused the test case to fail as it would expect a certain count while listing.

In this run: http://qa-proxy.ceph.com/teuthology/vshankar-2019-11-05_04:32:58-fs-wip-40867-testing-basic-mira/4474049/teuthology.log

2019-11-05T06:17:51.441 INFO:teuthology.orchestra.run.mira061:> sudo adjust-ulimits ceph-coverage /home/ubuntu/cephtest/archive/coverage timeout 120 ceph --cluster ceph fs subvolume snapshot create cephfs subvolume_7617 snapshot_17
2019-11-05T06:17:52.171 INFO:teuthology.orchestra.run.mira061:> sudo adjust-ulimits ceph-coverage /home/ubuntu/cephtest/archive/coverage timeout 120 ceph --cluster ceph fs subvolume snapshot create cephfs subvolume_7617 snapshot_17
2019-11-05T06:17:52.877 INFO:teuthology.orchestra.run.mira061:> sudo adjust-ulimits ceph-coverage /home/ubuntu/cephtest/archive/coverage timeout 120 ceph --cluster ceph fs subvolume snapshot create cephfs subvolume_7617 snapshot_15

^^ creating `snapshot_17` gets repeated twice. `mgr/volumes` treats idempotent create/remove operations as valid.