Moving to BTRFS

doublez13 · 02-20-2016, 07:52 PM

Hey guys!
I have three partitions...
An ext4 /boot partition
An ext4 / partition
A Btrfs partition not in use

Can I just do a simple "cp -r --preserve" on the entire / and modify grub to boot off the btrfs partition, or is there more work involved in switching?
Thanks.

Emerson · 02-20-2016, 08:00 PM

I'd boot from a live media and use 'cp -a'.

doublez13 · 02-20-2016, 08:06 PM

Oh that's smart. I forgot about symlinks.
Thanks!

jpollard · 02-20-2016, 08:12 PM

It depends on what you want to do.

1. ALWAYS make a backup.

Btrfs includes tools that can convert an ext4 filesystem into a btrfs filesystem without needing to copy files into a btrfs filesystem.

Before you do the /boot partition, make absolutely sure that your boot system can handle it... (grub2 looks like it can:

https://www.howtoforge.com/boot-on-btrfs-with-debian

The directions are for debian, but I don't think others using grub2 will be all that different.

syg00 · 02-20-2016, 08:31 PM

Copying from the ext to btrfs partition automatically creates a backup.

Standard chores after such a task:
- fix up fstab
- fix up the boot loader. This can be initiated from the old system as a update-grub/mkconfig will pick up both systems after the copy.

doublez13 · 02-21-2016, 09:17 AM

Thanks guys. Worked great!