NVMe can't be claimed as alba disk although available to claim as role

[khenderick]

From @kinvaris on June 21, 2016 12:14

I have a NVMe on my environment that I want to claim as alba backend disk but I can't. Although this is not possible on the backend page, it is possible to claim it for a role.

Copied from original issue: openvstorage/framework#644

[khenderick]

Extra information: The requirement for a disk as being usable as a plain disk (to be used as a cache disk, db disk, ...) is completely different from the requirements for it to be used as a backend disk.

[khenderick]

Current requirement for a disk to be available as backend disk:

Should be listed in /dev/disk/by-id/, starting with scsi-, ata- or virtio- and should be a symlink pointing to /dev/sd* or /dev/vd*.

Can you please add some information about the disks to this ticket (e.g. as what are they listed under /dev/disk/by-id/), so we can add support for these nvme drives?

[khenderick]

From @pploegaert on June 27, 2016 11:38

Not present in /dev/disk/by-id/

Present in /dev/ as nvm*

root@allflash184:/dev# ls -la nvm*
crw------- 1 root root 247, 0 Jun  6 12:48 nvme0
brw-rw---- 1 root disk 259, 0 Jun 24 16:53 nvme0n1
brw-rw---- 1 root disk 259, 1 Jun 24 17:15 nvme0n1p1

Partitioned but no filesystem present yet:

root@allflash184:/dev# parted /dev/nvme0n1
GNU Parted 2.3
Using /dev/nvme0n1
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p                                                                
Model: Unknown (unknown)
Disk /dev/nvme0n1: 1601GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End     Size    Type     File system  Flags
 1      1049kB  1601GB  1601GB  primary

[khenderick]

A quick fix that might be possible (instead of rewriting how disks are identified) is adding a symlink, e.g. /dev/disk/by-id/nvme-something -> ../../nvme0n1 and /dev/disk/by-id/nvm-something-part1 -> ../../nvme0n1p1, and then making a small patch in the code to accept this (that should be quite easy).

The only downside of this temporarily fix is that you have to add the symlinks beforehand, but for the POC and awaiting a more thorough fix this could be reasonable.

[kinvaris]

FAILED: This test failed, even when creating the symlinks. I was not able to add the NVMe to the backend.

ii  openvstorage                          2.7.2-rev.3867.ec9d46d-1                                 amd64        openvStorage
ii  openvstorage-backend                  1.7.2-rev.675.37ca5b8-1                                  amd64        openvStorage Backend plugin
ii  openvstorage-backend-core             1.7.2-rev.675.37ca5b8-1                                  amd64        openvStorage Backend plugin core
ii  openvstorage-backend-webapps          1.7.2-rev.675.37ca5b8-1                                  amd64        openvStorage Backend plugin Web Applications
ii  openvstorage-cinder-plugin            1.2.2-rev.32.948a8c1-1                                   amd64        OpenvStorage Cinder plugin for OpenStack
ii  openvstorage-core                     2.7.2-rev.3867.ec9d46d-1                                 amd64        openvStorage core
ii  openvstorage-hc                       1.7.2-rev.675.37ca5b8-1                                  amd64        openvStorage Backend plugin HyperConverged
ii  openvstorage-sdm                      1.6.2-rev.330.f06c8de-1                                  amd64        Open vStorage Backend ASD Manager
ii  openvstorage-webapps                  2.7.2-rev.3867.ec9d46d-1                                 amd64        openvStorage Web Applications

[openvstorage-ci]

This issue was moved to openvstorage/alba-asdmanager#121