Ceph

This is on luminous

Run: http://pulpito.ceph.com/yuriw-2018-05-04_00:39:32-rados-wip-yuri-testing_5.3.18-luminous-distro-basic-smithi/
Jobs (all same job reruns): '2473821', '2473819', '2473820'
Logs: http://qa-proxy.ceph.com/teuthology/yuriw-2018-05-04_00:39:32-rados-wip-yuri-testing_5.3.18-luminous-distro-basic-smithi/2473819/teuthology.log

{description: 'rados/singleton/{all/osd-recovery.yaml msgr-failures/few.yaml msgr/simple.yaml
    objectstore/filestore-xfs.yaml rados.yaml}', duration: 927.9632110595703, failure_reason: '"2018-05-04
    00:57:08.375377 mon.a mon.0 172.21.15.35:6789/0 103 : cluster [WRN] Health check
    failed: 6 slow requests are blocked > 32 sec. Implicated osds 1 (REQUEST_SLOW)" 
    in cluster log', flavor: basic, owner: scheduled_yuriw@teuthology, success: false}

Fix is needed in luminous (and upgrade suites that install luminous or earlier) only because REQUEST_SLOW has been dropped in mimic and above.