zfs / why "/dev/sdX" and not "/dev/disk/by-id/.." ?

[trendco]

I did a Test Installation with Proxmox-4 on 2x SSD's (Raid-1/Mirror).

"zpool status" shows:

root@proxmox-test:~# zpool status
  pool: rpool
 state: ONLINE
  scan: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        rpool       ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            sdb2    ONLINE       0     0     0
            sdc2    ONLINE       0     0     0

errors: No known data errors

Why use Proxmox the "/dev/sdX" Identifier and not "/dev/disk/by-id/.." as recommended here http://zfsonlinux.org/faq.html ?

 

[LnxBil]

And also interesting: How to change it.

(I also run into exactly this problem last week)

 

[dietmar]

newer zfs uses libblkid, and that always use /dev/sdX (as long as you do not use a cachefile).

 

[trendco]

And what happens when I add more Disks or swap the Cables and the Drive letter changes?

 

[dietmar]

And what happens when I add more Disks or swap the Cables and the Drive letter changes?

nothing.

 

[LnxBil]

What if I use a cache device? I tried and wasn't able to boot afterwards.

 

[fireon]

This is only with the rootpool. When you add an extrapool, it will show you with diskID. But it does not matter. ID is linked to SDX.

 

[mmenaz]

Forgive my ignorance, could you elaborate further? I know that hard disks are identified by something like /dev/sdXY, and that blkid is something like UUID="21f3c0c6-6f00-4ffe-98bf-b7feac3ddb9c", so your statement seems contradictory to me. I mean, if you are using blkid you should not have sdb2, right?
Thanks a lot

 

[dietmar]

so your statement seems contradictory to me. I mean, if you are using blkid you should not have sdb2, right?

It use libblkid to search for the correct disk, but always returns the found disk as /dev/sdX.