Migrate USB boot with iSCSI root Ubuntu to Proxmox VM

To convert Ubuntu to Proxmox Virtual Environment, the migration is required.

Ubuntu configuration

The Ubuntu server has following configuration

• Boots from USB device with /boot and /boot/efi filesystems.
• Connect to iSCSI host using GRUB2 configuration
• Root file system / is on iSCSI disk

Conversion

Create Proxmox VM

• Create VM with 2GB disk
• BIOS type is UEFI
• Add EFI disk
• Add Ubuntu Live CD and boot from CD

Create partition

Duplicating USB device partition to 2GB VM disk

Create filesystems

mkfs.vfat /dev/sda1
mkfs.btrfs /dev/sda2

Duplicate UUID

Duplicate UUID for /boot/efi

If don't change UUID for /boot/efi, later will need to change /etc/fstab file after reboot.

Duplicate UUID for /boot

Using following command to duplicate UUID for BTRFS filesystem

• Retrieve partition from USB Ubuntu

  sfdisk -d /dev/sda

• Create partitions on 2GB VM disk

• Duplicate UUID of partition /boot/efi

• Duplicate UUID of partition /boot

  btrfstune -U  /dev/sda2

Change network interface name in iSCSI configuration in Grub

• Retrieve network interface name

ip a

• Mount boot filesystem

mount /dev/sda2 /boot

• Edit file /boot/grub/grub.cfg

Change all interface names in the grub.cfg.

linux /vmlinuz-5.4.0-113-generic ... ip=192.168.1.99::192.168.1.254:255.255.255.0:fish:ensXX::192.168.1.55

Reboot VM

References

Modifying a BTRFS filesystem UUID

Change partition UUID in Ubuntu

Generate UUID

uuidgen

Change one partition

sgdisk -U <uuid> /dev/sda1

Change multiple partitions

Run following command to retrieve partitions info

sfdisk -d /dev/sda > /tmp/sda.dsk

Edit the UUID in the file /tmp/sda.dsk.

Run following command to reimport the modified partitions

sfdisk /dev/sda < /tmp/sda.dsk

References