Migrate Ubuntu on Btrfs to a New Disk

• System: Kubuntu 22.04
• There are two partitions on the original disk, EFI and Ubuntu root partition
• The Ubuntu root partition is using Btrfs filesystem, with two subvolumes, @ and @home

Create partitions

• Using sudo fdisk /dev/[disk] to partition
  • For example, sudo fdisk /dev/nvme1n1
• Create GPT partition table
• Create EFI partition, then change the partition type using t to change the type to EFI
• Create Linux partition main partition

Copy EFI partition

sudo dd if=/dev/nvme0n1p1 of=/dev/nvme1n1p1 status=progress

Copy Btrfs partition

• Boot into a live USB Linux
• Assume the Btrfs partition is /dev/nvme0n1p2 and the new disk is /dev/nvme1n1p2
• Mount the old Btrfs partition

mount /dev/nvme0n1p2 /mnt

• Start copying the Btrfs partition

btrfs replace start /dev/nvme0n1p2 /dev/nvme1n1p2 /mnt

• Check the progress

btrfs replace status /mnt

• This method should keep all the Btrfs subvolumes and UUIDs.

Or Copy Linux partition using dd

sudo dd if=/dev/nvme0n1p2 of=/dev/nvme1n1p2 status=progress

• This method will keep the original Btrfs partition’s UUID, so there is no need to modify the /etc/fstab file.
• The reason for using dd instead of rsync is that this way the Btrfs subvolume information is preserved.
• This step is recommended to be done using a live USB Linux.

Other operations

Resize the btrfs partition to use the entire disk

sudo btrfs filesystem resize max [mounting point]

Check if the partition has any issues

sudo btrfs check /dev/nvme1n1p2

View UUID

sudo blkid

Backup important files to another disk

• Mount the disk to be migrated and another backup disk

rsync -avx --info=progress2 --info=name0 --info=stats2 --info=flist0 /source_directory/ /destination_directory/

Another method

• If the two disks have the same size, you can use dd to copy the entire disk
• For example dd if=/dev/sda of=/dev/sdb bs=4096

reference

• BTRFS 分区迁移记录