Re: [newb] move /home to subvolume

[Neal Becker <ndbecker2@gmail.com>]

Chris Murphy wrote:

> On Mon, Jun 1, 2015 at 6:36 AM, Neal Becker <ndbecker2@gmail.com> wrote:
>> I have everything under /:
>>
>> sudo btrfs subvolume list /
>> ID 257 gen 65795 top level 5 path root
> 
> root is a subvolume, but is not the top level (default) subvolume.
>>
>> I want to move /home onto it's own subvolume.  I hope I can do this while
>> the root device is mounted.
> 
> Yes.
> 
> You need to mount the top level and create a new subvolume. Assuming
> you haven't changed the default subvolume, just mount the device
> normally:
> 
> mount /dev/sdaX /mnt
> btrfs sub create /mnt/home
> cp -a --reflink /mnt/root/home /mnt/
> vi /etc/fstab ## to add an entry to mount subvol=home at /home
> umount /home
> mount /home
> 
> And then at your leisure you can blow away the contents of the copied
> and no longer used /home directory still in the root subvolume. Just
> be certain you're deleting the correct home. You could:
> cd /mnt/root/home
> rm -rf *     ## egads be certain
> 
> This is not a mount point, but the old home directory which is no
> longer in use. The path to the in use one is /mnt/home as well as
> /home (in the above example).
> 

Thanks, this all worked just fine.  Only thing I did differently, I needed 
to rename the old /home to /oldhome and mkdir /home for the new subvol 
mount, so that I now have /home and /oldhome and can, at my leisure, rm -rf 
oldhome (otherwise, mounting /home would have hidden the old /home and made 
it impossible to rm).