Re: Cannot resize filesystem: not enough free space

[Hugo Mills <hugo@carfax.org.uk>]

On Sun, Jan 24, 2021 at 08:11:37PM +0100, Jakob Schöttl wrote:
> 
> Hugo Mills <hugo@carfax.org.uk> writes:
> 
> > On Sun, Jan 24, 2021 at 07:23:21PM +0100, Jakob Schöttl wrote:
> > > 
> > > Help please, increasing the filesystem size doesn't work.
> > > 
> > > When mounting my btrfs filesystem, I had errors saying, "no space
> > > left
> > > on device". Now I managed to mount the filesystem with -o
> > > skip_balance but:
> > > 
> > > # btrfs fi df /mnt
> > > Data, RAID1: total=147.04GiB, used=147.02GiB
> > > System, RAID1: total=8.00MiB, used=48.00KiB
> > > Metadata, RAID1: total=1.00GiB, used=458.84MiB
> > > GlobalReserve, single: total=181.53MiB, used=0.00B
> > 
> >    Can you show the output of "sudo btrfs fi show" as well?
> > 
> >    Hugo.
> 
> Thanks, Hugo, for the quick response.
> 
> # btrfs fi show /mnt/
> Label: 'data'  uuid: fc991007-6ef3-4c2c-9ca7-b4d637fccafb
>        Total devices 2 FS bytes used 148.43GiB
>        devid    1 size 232.89GiB used 149.05GiB path /dev/sda
>        devid    2 size 149.05GiB used 149.05GiB path /dev/sdb
> 
> Oh, now I see! Resize only worked for one sda!
> 
> # btrfs fi resize 1:max /mnt/
> # btrfs fi resize 2:max /mnt/
> # btrfs fi show /mnt/
> Label: 'data'  uuid: fc991007-6ef3-4c2c-9ca7-b4d637fccafb
>        Total devices 2 FS bytes used 150.05GiB
>        devid    1 size 232.89GiB used 151.05GiB path /dev/sda
>        devid    2 size 465.76GiB used 151.05GiB path /dev/sdb
> 
> Now it works. Thank you!

   Note that the new configuration is going to waste about 232 GiB of
/dev/sdb, because you've got RAID-1, and there won't be spare space to
mirror anything onto once /dev/sda fills up.

   You can add a third device of 232 GiB (250 GB) or more to the FS
and that'll allow the use of the remaining space on /dev/sdb.

   Hugo.

> > > It is full and resize doesn't work although both block devices sda
> > > and
> > > sdb have more 250 GB and more nominal capacity (I don't have
> > > partitions,
> > > btrfs is directly on sda and sdb):
> > > 
> > > # fdisk -l /dev/sd{a,b}*
> > > Disk /dev/sda: 232.89 GiB, 250059350016 bytes, 488397168 sectors
> > > [...]
> > > Disk /dev/sdb: 465.76 GiB, 500107862016 bytes, 976773168 sectors
> > > [...]
> > > 
> > > I tried:
> > > 
> > > # btrfs fi resize 230G /mnt
> > > runs without errors but has no effect
> > > 
> > > # btrfs fi resize max /mnt
> > > runs without errors but has no effect
> > > 
> > > # btrfs fi resize +1G /mnt
> > > ERROR: unable to resize '/mnt': no enough free space
> > > 
> > > Any ideas? Thank you!
> 
> 

-- 
Hugo Mills             | Have found Lost City of Atlantis. High Priest is
hugo@... carfax.org.uk | winning at quoits.
http://carfax.org.uk/  |
PGP: E2AB1DE4          |                                       Terry Pratchett