Proxmox debian cloud-init disk name unstable

[PeterAndersson]

Hi I have the following script

qm create "$VMID" --name "debian-docker" --memory 10240 --sockets 1 --core 4 --net0 virtio="46:4A:5E:3C:8A:55",bridge=vmbr0 --description "Debian bullseye cloud image" --agent enabled=1
qm set "$VMID" --ide2 "$STORAGE:cloudinit"
qm set "$VMID" --serial0 socket --vga serial0
qm importdisk "$VMID" "/tmp/$IMAGE" "$STORAGE"
qm set "$VMID" --scsihw virtio-scsi-pci --scsi0 "$STORAGE:vm-$VMID-disk-0,backup=0"
# Move cloud init file to snipet folder
qm set "$VMID" --cicustom "user=snippets:snippets/$VMID-$SNIPPETNAME"
qm set "$VMID" --boot c --bootdisk scsi0
qm set "$VMID" --scsi1 "$STORAGE:128"
qm start "$VMID"

This does the following:

1. creates a new VM
2. adds a debian no cloud as boot disk
3. sets vga via serial
4. adds cloud init
5. adds a secondary data disk

Then in my cloud init file I have the following:

disk_setup:
  /dev/sda:
    table_type: 'gpt'
    layout:
      - 95
      - 5

fs_setup:
  - label: persistent_app
    filesystem: 'ext4'
    device: /dev/sda1
    partition: 'auto'
  - label: persistent_user
    filesystem: 'ext4'
    device: /dev/sda2
    partition: 'auto'

The problem is that it seems a bit random if the data disk is mounted under /dev/sda or /dev/sdb is there some way to force them to always be in the same order?

 

[leesteken]

Maybe use /dev/disk/by-path/...? Those paths depend on the SCSI/IDE controller and the SCSI/IDE number of the drive (which you control in the VM configuration).

 

[PeterAndersson]

Maybe use /dev/disk/by-path/...? Those paths depend on the SCSI/IDE controller and the SCSI/IDE number of the drive (which you control in the VM configuration).

Thanks that makes more sense, so for my current disk the path is then /dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1.
I'm running debian cloud image as stated and it uses cloud-init 20.4.1 but it seems the following doesn't work

disk_aliases: #Found a bug saying the name should be disk not device so tried both just to be sure
  'data0': '/dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1'

device_aliases:
  'data0': '/dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1'

disk_setup:
  data0:
    table_type: 'gpt'
    layout:
      - 95
      - 5

fs_setup:
  - label: persistent_app
    filesystem: 'ext4'
    device: data0.1
    partition: 'auto'
  - label: persistent_user
    filesystem: 'ext4'
    device: data0.2
    partition: 'auto'

When I inspect the disk using parted it just says Partition Table: unknown so I'm guessing device_aliases isn't supported even when its in the documentation? https://cloudinit.readthedocs.io/en/20.4.1/topics/modules.html?highlight=fs_setup#disk-setup

Sadly I'm having a hard time finding the log line where the disk_setup fails so I'm not 100% sure.

So then I tried the following:

disk_setup:
  '/dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1':
    table_type: 'gpt'
    layout:
      - 95
      - 5

fs_setup:
  - label: persistent_app
    filesystem: 'ext4'
    device: '/dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1'
    partition: 1
    partition: 'auto'
  - label: persistent_user
    filesystem: 'ext4'
    device: '/dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1'
    partition: 2
    partition: 'auto'

Now it formats the disk correctly with 2 partitions, but the partitions aren't formatted..

The problem seems to be that the partitions are listed under /dev/disk/by-path/ with -part1/2 instead of .1/2 so I have no way of specifying the path to fs_setup as it just looks for the last . in the path and everything behind that is counted as the partition, but in this case the device name contains a dot. I even tried with pci-0000:00:05.0-scsi-0:0:0:1.-part1 but the dot is kept when it looks for the device and causes it to fail.

 

[leesteken]

Sorry but I have no experience with cloudinit. I only know that the paths under /dev/disk/by-... are much more stable than /dev/sd*.

- label: persistent_app
filesystem: 'ext4'
device: '/dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1'
partition: 1
partition: 'auto'

I would not expect partition twice. I guess you already tried something like this?

      - label: persistent_app
        filesystem: 'ext4'
        device: '/dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1-part1'