Multipath and Ceph OSD

[JohnJames]

I'm trying to figure out what physicals disk maps to what OSD. I'm getting error values on /dev/sdx, but don't know what OSD it uses. Currently using multipath.

 

[alexskysilk]

your multipath devices are dm devices (/dev/dm-*), and should also have autocreated symlinks in /dev/mapper.

 

[JohnJames]

your multipath devices are dm devices (/dev/dm-*), and should also have autocreated symlinks in /dev/mapper.

/dev/dm-* = osd.* ?

 

[alexskysilk]

Assuming you're using current (>Luminous) your OSDs are on LVM; if you check your block devices (lsblk) you'll see your disks having a volume group named "ceph--xxx" on them

If you see volume groups on disks as sdx, you're not using multipath. if you see the disks as /dev/mapper or as WWNs, then you are.