Create OSD on device mapper, multipath

[Neb]

Hello

I'm trying to create a ceph osd on multipath device /dev/mapper/mpathX, but I get this error each time I try to run

pveceph createosd /dev/mapper/mpathX

=> "unable to get device info for dm-3".

ls -l /dev/mapper/mpathb
lrwxrwxrwx 1 root root 7 août  21 16:26 /dev/mapper/mpathX -> ../dm-3

Why ?

How can I solve this issue ? any idea ?

Thank you

proxmox-ve: 5.0-20 (running kernel: 4.10.17-2-pve)
pve-manager: 5.0-30 (running version: 5.0-30/5ab26bc)
pve-kernel-4.10.17-2-pve: 4.10.17-20
libpve-http-server-perl: 2.0-6
lvm2: 2.02.168-pve3
corosync: 2.4.2-pve3
libqb0: 1.0.1-1
pve-cluster: 5.0-12
qemu-server: 5.0-15
pve-firmware: 2.0-2
libpve-common-perl: 5.0-16
libpve-guest-common-perl: 2.0-11
libpve-access-control: 5.0-6
libpve-storage-perl: 5.0-14
pve-libspice-server1: 0.12.8-3
vncterm: 1.5-2
pve-docs: 5.0-9
pve-qemu-kvm: 2.9.0-4
pve-container: 2.0-15
pve-firewall: 3.0-2
pve-ha-manager: 2.0-2
ksm-control-daemon: not correctly installed
glusterfs-client: 3.8.8-1
lxc-pve: 2.0.8-3
lxcfs: 2.0.7-pve4
criu: 2.11.1-1~bpo90
novnc-pve: 0.6-4
smartmontools: 6.5+svn4324-1
ceph: 12.1.2-pve1

 

[manu]

what is actually your use case here ? ceph will do the high availability disk management for your disks, so you should'nt need to add a multipath device but the real hard drive to the pveceph createosd command

 

[Neb]

Thank you manu.

The disks that we use are SAN disks. So in order to have no SPoF we set up multipath. But I see, it is may be useless with Ceph ?