While in LiveUSB, I found
Deleting an Apt-snapshot Btrfs Subvolume Is Hard
and following it, I was able to delete about 25 @apt-snapshot- one at a time. For some reason:
root@ubuntu:~#/ btrfs subvol delete /mnt/tmp/@apt-snapshot-*
would not work in a Live session (LiveCD or Live USB). And I had to be in the /dev directory to make deletions. The snapshots could only be deleted by copying the snapshot line from within the terminal and pasting them into the end of the delete argument.
But having manually deleted 2 pages of snapshots from seeing them in ls -l /mnt/tmp/, I was able to reboot in a regular manner, obtaining a working OS & Desktop.
Returning to the Deleting ... is Hard post, in a regular OS session, I was able to completely remove approx. 160 of the snapshots remaining, using
btrfs subvolume delete @apt-snapshot-*
There were some odd lines leftover:
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-08-26_19:55:19'
ERROR: cannot delete '/mnt/tmp/@apt-snapshot-2013-08-26_19:55:19' - Directory not empty
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-09_10:13:00'
ERROR: cannot delete '/mnt/tmp/@apt-snapshot-2013-09-09_10:13:00' - Directory not empty
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-09_10:13:01'
ERROR: cannot delete '/mnt/tmp/@apt-snapshot-2013-09-09_10:13:01' - Directory not empty
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-19_08:35:07'
ERROR: cannot delete '/mnt/tmp/@apt-snapshot-2013-09-19_08:35:07' - Directory not empty
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-19_08:35:42'
ERROR: cannot delete '/mnt/tmp/@apt-snapshot-2013-09-19_08:35:42' - Directory not empty
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-19_08:35:43'
ERROR: cannot delete '/mnt/tmp/@apt-snapshot-2013-09-19_08:35:43' - Directory not empty
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-19_08:38:35'
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-24_09:11:04'
ERROR: cannot delete '/mnt/tmp/@apt-snapshot-2013-09-24_09:11:04' - Directory not empty
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-24_09:11:05'
ERROR: cannot delete '/mnt/tmp/@apt-snapshot-2013-09-24_09:11:05' - Directory not empty
Delete subvolume '/mnt/tmp/@apt-snapshot-2013-09-25_08:36:59'
and a double check of that:
mark@Lexington:/$ sudo btrfs subvol list /
ID 256 gen 105872 top level 5 path @
ID 317 gen 105688 top level 5 path @apt-snapshot-2013-08-26_19:55:19
ID 318 gen 43813 top level 5 path @apt-snapshot-2013-08-26_19:55:19/@
ID 352 gen 105683 top level 5 path @apt-snapshot-2013-09-09_10:13:00
ID 353 gen 60062 top level 5 path @apt-snapshot-2013-09-09_10:13:00/@
ID 354 gen 105683 top level 5 path @apt-snapshot-2013-09-09_10:13:01
ID 355 gen 60064 top level 5 path @apt-snapshot-2013-09-09_10:13:01/@
ID 378 gen 71723 top level 5 path @apt-snapshot-2013-09-19_08:35:07
ID 379 gen 71724 top level 5 path @apt-snapshot-2013-09-19_08:35:07/@
ID 380 gen 71729 top level 5 path @apt-snapshot-2013-09-19_08:35:42
ID 381 gen 71730 top level 5 path @apt-snapshot-2013-09-19_08:35:42/@
ID 382 gen 71731 top level 5 path @apt-snapshot-2013-09-19_08:35:43
ID 383 gen 71732 top level 5 path @apt-snapshot-2013-09-19_08:35:43/@
ID 395 gen 77954 top level 5 path @apt-snapshot-2013-09-24_09:11:04
ID 396 gen 77955 top level 5 path @apt-snapshot-2013-09-24_09:11:04/@
ID 397 gen 77956 top level 5 path @apt-snapshot-2013-09-24_09:11:05
ID 398 gen 77957 top level 5 path @apt-snapshot-2013-09-24_09:11:05/@
Now on to fixing the @ seeing a @home incorrectly.
After the deletions this is the reported free space. This seems extraordinary to me, that 50% of 19gig is used.
mark@Lexington:~$ df -hT | egrep -i "file|^/"
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda1 btrfs 19G 7.8G 8.1G 50% /
/dev/sda6 btrfs 347G 87G 259G 26% /home
Is it necessary to keep all those snapshots for the btrfs? And since I can't delete them anyway, why does btrfs want them? Seems like a lot. In practical matters, I would have to find a significant reason to expand a boot time partition to more than 18 gig. Most Ubuntu uses 8 to 10 gig.