I have started a test. As the target is an USB stick (so slow...) it can take a
long time, so please be patient and wait until I give you a "go" before applying
the instructions below.
Meanwhile you can already prepare the internal drive.
All commands below should be typed as root or using sudo.
First as recommended by Forza here:
https://wiki.tnonline.net/w/Btrfs/Replacing_a_disk
issue blkdiscard to clear the internal disk (assuming it's an SSD):
blkdiscard /dev/sda -v
Then make at least two partitions on /dev/sda using gdisk or cgdisk
1. a partition of size 100M, type EFI system (code ef00)
2. a partition use the remaining space, type Linux (thios is the default)
Then format the first partition:
mkfs.fat /dev/sda
Do *not* format the second partition.
Tell us if you need help to use the commands cgdisk or gdisk
For cgdisk type "cgdisk -a /dev/sda" which makes this utility more accessible
(for the records, fulfilling a request from Philippe Delavalade many years ago).
Notes :
a. You may choose to create other partitions on /dev/sda, but the partition
/dev/sda2 should be at least as big as the partition mounted as / on the
external drive (but you can easily shrink the latter first if you want. I will
tell you how if that is the case).
b. I assume that this machine will only boot on EFI mode. Else a not formatted
partition of type BIOS Boot (code ef02) size 4M is also needed to make GRUB
happy.
Once /dev/sda has been prepared, do this after I give you the "go":
1. Remount the partition hosting / as /mnt
As you installed in auto mode I assume that this is /dev/sdb3, which you can
check with this command:
findmnt -no source /|cut -d[ -f 1
2. Then just type:
mount /dev/sdb3 /mnt
3. To replace (move) the root file system (from) /dev/sdb3 by (to) /dev/sda2
type:
btrfs replace start 1 /dev/sda2 /mnt
In this command 1 is the device number (should be 1 as this is file system on a
single device), /dev/sda2 the new partition (new location of the file system)
and /mnt the mount point of the current one.
This will take a long time.
You can check the progress typing:
btrs replace status /mnt
You can do that several times (type Ctrl+C get back the prompt)
When the replacement will be completed just reinstall and update grub:
grub-install /dev/sda
update-grub
After that you can check the layout of the new GRUB boot menu typing:
list-boot-entries
You should not have to edit /etc/fstab as the UUID of the root file system will
not have changed.
Here the replacement is done at 77.9%, so expect a "go" or a "no go" in less
than one hour ;)
Meanwhile, questions?
Cheers,
Didier
Le 03/06/2023 à 18:09, Pawel Loba a écrit :
The output of your command is:===============================================================================
/dev/sda
/dev/sdb
where sda i the internal and sdb is the external hard drive.
Thank you,
Pawel
On 6/3/23, Didier Spaier <didier@xxxxxxxx> wrote:
I meant the drive name, as listed in the output of:
lsblk -lpo name,type|grep disk|cut -d" " -f1
Le 03/06/2023 à 19:29, Pawel Loba a écrit :
Machine name on the external drive is deimos.
On 6/3/23, Didier Spaier <appartement.cdm@xxxxxxx> wrote:
Then that will be easy.
I just chatted with btrfs experts to find the simplest way. I will try
locally
before sending a detailed how-to. Meanwhile please tell how the external
internal drive is named.
Cheers,
Didier
Le 03/06/2023 à 18:39, Pawel Loba a écrit :
The internal drive is completely empty with 2 TB space.
The external one was created with auto mode and its size is close to 1
TB.
Thanks,
Pawel
On 6/3/23, Didier Spaier <appartement.cdm@xxxxxxx> wrote:
Probably. Did you install it in auto mode? And do you have an ESP (EFI
System partition) in the internal drive as well as a big enough unused
partition or free space on this drive?
