Re: [PVE-User] Matching WUI VM hardware disks to Linux guest disks

Re: [PVE-User] Matching WUI VM hardware disks to Linux guest disks

[Dominik Csapak]

hi,

you can check out
`lsblk -o +serial`

should output something like:

NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT              SERIAL
sda      8:0    0   50G  0 disk                         drive-scsi0
└─sda1   8:1    0   50G  0 part /
sdb      8:16   0  100G  0 disk                         drive-scsi9
└─sdb1   8:17   0  100G  0 part /mnt/foo
sdc      8:32   0    2G  0 disk                         drive-scsi5
├─sdc1   8:33   0    2G  0 part
└─sdc9   8:41   0    8M  0 part
sdd      8:48   0    2G  0 disk                         drive-scsi4
├─sdd1   8:49   0    2G  0 part
└─sdd9   8:57   0    8M  0 part
sde      8:64   0    2G  0 disk                         drive-scsi3
├─sde1   8:65   0    2G  0 part
└─sde9   8:73   0    8M  0 part
sdf      8:80   0   50G  0 disk                         drive-scsi2
└─sdf1   8:81   0   50G  0 part /mnt/bar
sdg      8:96   0  200G  0 disk                         drive-scsi1
└─sdg1   8:97   0  200G  0 part /mnt/baz
sr0     11:0    1 1024M  0 rom                          QM00003

Re: [PVE-User] Matching WUI VM hardware disks to Linux guest disks

[Chris Hofstaedtler | Deduktiva]

Hi,

* Eneko Lacunza via pve-user <pve-user@lists.proxmox.com> [201110 09:03]:
> I have hit a simple problem. Let be a VM with 3 disks, with .conf extract:
> 
> scsi0: ceph-proxmox:vm-100-disk-1,cache=writeback,size=6G
> scsi1: ceph-proxmox:vm-100-disk-0,cache=writeback,size=400G
> scsi2: ceph-proxmox:vm-100-disk-3,cache=writeback,size=400G
> 
> We have two virtual disks with identical size (400G).
> 
> How can I be sure what device on Linux guest is each?

You can also check - and use in /etc/fstab - the /dev/disk/by-*
symlinks.

In a VM, maybe the most relevant "id" is the actual path.
/dev/disk/by-path has these links (in my case):

  pci-0000:06:05.0-scsi-0:0:0:0 -> sda
  pci-0000:00:05.0-scsi-0:0:0:1 -> sdb

If your sdb/sdc are swapped, the SCSI IDs in the path should still
be correct.

If you don't like the pci path in there, /dev/disk/by-id has:
  scsi-0QEMU_QEMU_HARDDISK_drive-scsi0 -> sda
  scsi-0QEMU_QEMU_HARDDISK_drive-scsi1 -> sdb

But you'll have to check if those match with the VM settings (I'd
expect them to).

As you've discovered and others have said, lsscsi, or lsblk -S can
be used to see the SCSI IDs, too. The same info is also availabe
from udevadm: udevadm info /dev/sda
If you dig around in /sys, it's also there ;-)

HTH,
Chris
-- 
Chris Hofstaedtler / Deduktiva GmbH (FN 418592 b, HG Wien)
www.deduktiva.com / +43 1 353 1707