Re: Change BTRFS filesystem back to R/W from R/O

[Spencer Collyer <spencer@spencercollyer.plus.com>]

(Resending to the list as I accidentally sent it just to Qu.)

On Tue, 15 Nov 2022 20:41:54 +0800, Qu Wenruo wrote:

> Considering you have some metadata space left, I believe you can free 
> enough space by deleting files (aka, moving it to other filesystems)
> 
> Thanks,
> Qu  

Hi Qu,

Thanks for that. You say I should move some files to other filesystems, but that's really the nub of my problem - the filesystem is marked as read-only. Am I Ok to do what I mentioned previously:

> 1) Unmount the filesystem.
> 2) Remount it as R/W
> 3) Move data to the external disk  

If that is all good, would I need to do anything else or would the BTRFS system sort itself out correctly?

Thanks for your attention,

Spencer

PS. The output form the 'btrfs fi usage /data' command you requested is as follows (run as root to get everything):

Overall:
    Device size:		  10.92TiB
    Device allocated:		  10.92TiB
    Device unallocated:		   1.00MiB
    Device missing:		     0.00B
    Device slack:		     0.00B
    Used:			  10.90TiB
    Free (estimated):		  15.26GiB	(min: 15.26GiB)
    Free (statfs, df):		  15.26GiB
    Data ratio:			      1.00
    Metadata ratio:		      2.00
    Global reserve:		 512.00MiB	(used: 0.00B)
    Multiple profiles:		       yes	(metadata, system)

Data,RAID0: Size:10.87TiB, Used:10.86TiB (99.86%)
   /dev/mapper/data1	   5.44TiB
   /dev/mapper/data2	   5.44TiB

Metadata,single: Size:8.00MiB, Used:0.00B (0.00%)
   /dev/mapper/data1	   8.00MiB

Metadata,RAID1: Size:23.00GiB, Used:21.39GiB (93.00%)
   /dev/mapper/data1	  23.00GiB
   /dev/mapper/data2	  23.00GiB

System,single: Size:4.00MiB, Used:0.00B (0.00%)
   /dev/mapper/data1	   4.00MiB

System,RAID1: Size:8.00MiB, Used:784.00KiB (9.57%)
   /dev/mapper/data1	   8.00MiB
   /dev/mapper/data2	   8.00MiB

Unallocated:
   /dev/mapper/data1	     0.00B
   /dev/mapper/data2	   1.00MiB