I'm trying to get the SSH orchestrator running for testing the MDS Autoscaler.
I start the vstart cluster with:
$ MDS=3 ../src/vstart.sh -d -b -l -n --without-dashboard --cephadm

Processes seem to launch without errors until:
/home/mchangir/work/mchangir-ceph.git/build/bin/ceph -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf -k /home/mchangir/work/mchangir-ceph.git/build/keyring fs volume create a
Error EINVAL: Remote method threw exception: TypeError: %d format: a number is required, not NoneType

Still digging at it. But no leads so far.
Let me know where should I be looking for this one.
The mgr plugin and related utilities python code looks okay to me. But I'm not 100% sure.
Will this failure get in my way for testing the MDS Autoscaler ?
Also, `ceph status` shows the system in HEALTH_WARN state like so:
$ ./bin/ceph status
2020-01-28T18:03:48.542+0530 7f4ddb872700 -1 WARNING: all dangerous and experimental features are enabled.
2020-01-28T18:03:48.558+0530 7f4dda610700 -1 WARNING: all dangerous and experimental features are enabled.
    id:     e717ee71-d1e3-4be4-b771-1fface003e13
    health: HEALTH_WARN
            1 stray host(s) with 10 service(s) not managed by cephadm
            10 stray service(s) not managed by cephadm
    mon: 3 daemons, quorum a,b,c (age 2h)
    mgr: x(active, since 2h)
    mds: a:1 {0=a=up:active} 2 up:standby
    osd: 3 osds: 3 up (since 2h), 3 in (since 2h)
    pools:   2 pools, 64 pgs
    objects: 22 objects, 2.2 KiB
    usage:   6.0 GiB used, 297 GiB / 303 GiB avail
    pgs:     64 active+clean
Is this the correct way to remove an mds via the orchestrator:
$ ./bin/ceph orchestrator mds rm c
Error ENOENT: Unable to find mds.c[-*] daemon(s)

but the daemons are indeed running:
$ pgrep -a ceph-
1310763 /usr/libexec/platform-python -s /usr/bin/ceph-crash -n client.crash.localhost.localdomain
1624818 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-mon -i a -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1624861 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-mon -i b -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1624904 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-mon -i c -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1626022 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-osd -i 0 -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1626376 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-osd -i 1 -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1626707 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-osd -i 2 -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1626895 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-mds -i a -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1626950 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-mds -i b -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1627005 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-mds -i c -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf
1676260 /home/mchangir/work/mchangir-ceph.git/build/bin/ceph-mgr -i x -c /home/mchangir/work/mchangir-ceph.git/build/ceph.conf

Is the exception (in red) caused because of a missing placement spec ?

Ideally I'd like to launch a standby MDS without any affinity to a filesystem or an OSD.
Any help to get this correctly implemented/tested will be appreciated.