ceph rbd map in ubuntu 16.04 fails with map failed: (6) No such device or address

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Ubuntu 16.04 with ceph cluster ok

root@x4600:~# ceph --version

ceph version 10.1.2 (4a2a6f72640d6b74a3bbd92798bb913ed380dcd4)

root@x4600:~# ceph status
    cluster 9ed0acb4-425c-4d09-a693-471ed6391d6b
     health HEALTH_WARN
            too many PGs per OSD (490 > max 300)
     monmap e2: 3 mons at {cephmon1=10.10.25.105:6789/0,cephmon2=10.10.25.106:6789/0,cephmon3=10.10.25.107:6789/0}
            election epoch 8, quorum 0,1,2 cephmon1,cephmon2,cephmon3
     osdmap e254: 46 osds: 46 up, 46 in
            flags sortbitwise
      pgmap v141576: 11280 pgs, 13 pools, 278 MB data, 291 objects
            232 GB used, 85424 GB / 85656 GB avail
               11280 active+clean

rbd create is ok:

root@x4600:~# rbd create rbd/pippo --size 10240 --image-format 2

rbd ls is ok:

root@x4600:~# rbd ls
pippo

rbd map fails

root@x4600:~# rbd map rbd/pippo
rbd: sysfs write failed
rbd: map failed: (6) No such device or address

[yexian (yexianwolail)]

 me too

[Jason Dillaman (jdillaman)]

Please see the Jewel release notes [1] regarding this change. Specifically, Ceph, by default, creates new RBD images using features currently unsupported by krbd. You can disable these features on an existing image using the 'rbd feature disable' command or you can revert to pre-Jewel features for all new images by adding "rbd default features = 1" in your Ceph configuration file.

[1] http://docs.ceph.com/docs/master/release-notes/#upgrading-from-infernalis-or-hammer

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[James Page (james-page)]

The mismatch between backend (ceph) and kernel features does appear to be a bit of a problem; that said it is avoidable by configuration, so marking as 'Low' for now; it might be nice to try to align the default so that everything in Ubuntu just DTRT but that might not be easily achievable without breaking something else.

[Nils Meyer (nils-nm)]

Also bear in mind that the kernel version used by Ubuntu does not support tunables5, these are only uspported starting with kernel 4.5.

[James Page (james-page)]

Marking this as 'Won't Fix' - its a fairly well know configuration change and diverging Ubuntu from the rest of the world won't help to much.