How to clean old snaps?
ubuntu linux snap cleanup bash
This knowledge base entry is for those using snap
package manager. After using it for a while, you might notice
that snap keeps previous versions of installed software. It is
made in a smart way so that it does not take much space, however
it creates loop devices for each version. This makes
output of df -h command pretty unreadable. The first
solution I've came up with is to remove old revisions so that
precious SSD space is being freed and there are lessen loop
devices.
Cleaning up Snaps
Surprisingly the snap itself does not offer any tools for cleaning up old revisions. After googling and reading, I've came with solution for removing old revisions with this simple bash script (sorry credits are lost, I'm not the author of this script):
#!/bin/bash
# Removes old revisions of snaps
# CLOSE ALL SNAPS BEFORE RUNNING THIS
set -eu
snap list --all | awk '/disabled/{print $1, $3}' |
while read snapname revision; do
snap remove "$snapname" --revision="$revision"
done
I've named this script snaps-clean and saved in by
~/bin/ directory. This script requires root to work
properly, when ran without sudo will display
appropriate message.
Results
Before applying script I had 36 loop devices! But you might have even more:
[~]$ df -h Filesystem Size Used Avail Use% Mounted on udev 3,9G 0 3,9G 0% /dev tmpfs 787M 2,1M 785M 1% /run /dev/sda3 140G 109G 25G 82% / tmpfs 3,9G 58M 3,8G 2% /dev/shm tmpfs 5,0M 4,0K 5,0M 1% /run/lock tmpfs 3,9G 0 3,9G 0% /sys/fs/cgroup /dev/loop2 148M 148M 0 100% /snap/obs-studio/525 /dev/loop1 194M 194M 0 100% /snap/mailspring/368 /dev/loop3 2,3M 2,3M 0 100% /snap/gnome-calculator/260 /dev/loop4 1,0M 1,0M 0 100% /snap/gnome-logs/57 /dev/loop5 141M 141M 0 100% /snap/gnome-3-26-1604/88 /dev/loop0 152M 152M 0 100% /snap/arduino-mhall119/5 /dev/loop6 89M 89M 0 100% /snap/core/6964 /dev/loop10 89M 89M 0 100% /snap/core/7270 /dev/loop7 152M 152M 0 100% /snap/gnome-3-28-1804/59 /dev/loop9 94M 94M 0 100% /snap/telegram-desktop/753 /dev/loop13 4,2M 4,2M 0 100% /snap/gnome-calculator/406 /dev/loop14 3,8M 3,8M 0 100% /snap/gnome-system-monitor/91 /dev/loop12 108M 108M 0 100% /snap/robo3t-snap/3 /dev/loop15 111M 111M 0 100% /snap/robo3t-snap/4 /dev/loop18 35M 35M 0 100% /snap/gtk-common-themes/1122 /dev/loop17 148M 148M 0 100% /snap/obs-studio/439 /dev/loop11 36M 36M 0 100% /snap/gtk-common-themes/1198 /dev/loop19 4,2M 4,2M 0 100% /snap/gnome-calculator/352 /dev/loop22 54M 54M 0 100% /snap/core18/1013 /dev/loop25 225M 225M 0 100% /snap/polarr/9 /dev/loop23 35M 35M 0 100% /snap/gtk-common-themes/818 /dev/loop26 1,0M 1,0M 0 100% /snap/gnome-logs/61 /dev/loop28 265M 265M 0 100% /snap/phpstorm/98 /dev/loop30 15M 15M 0 100% /snap/gnome-logs/45 /dev/loop31 15M 15M 0 100% /snap/gnome-characters/288 /dev/loop32 95M 95M 0 100% /snap/telegram-desktop/818 tmpfs 787M 4,1M 783M 1% /run/user/1000 /dev/sda1 73G 55G 18G 76% /media/peter/Windows /dev/loop34 194M 194M 0 100% /snap/mailspring/374 /dev/sdb1 932G 643G 290G 69% /media/peter/Dane /dev/loop16 55M 55M 0 100% /snap/core18/1049 /dev/loop20 265M 265M 0 100% /snap/phpstorm/104 /dev/loop21 3,8M 3,8M 0 100% /snap/gnome-system-monitor/95 /dev/loop27 15M 15M 0 100% /snap/gnome-characters/292 /dev/loop35 141M 141M 0 100% /snap/gnome-3-26-1604/90 /dev/loop33 150M 150M 0 100% /snap/gnome-3-28-1804/63 /dev/sdc1 1,8T 1,1T 674G 62% /media/peter/Data2
The script runs pretty fast, and the results are sufficient, however we'll do another trick later.
The output of the snaps-clean script
[~]$ sudo ./bin/snaps-clean core (revision 6964) removed core18 (revision 1013) removed gnome-3-26-1604 (revision 88) removed gnome-3-28-1804 (revision 59) removed gnome-calculator (revision 352) removed gnome-calculator (revision 260) removed gnome-characters (revision 288) removed gnome-logs (revision 45) removed gnome-logs (revision 57) removed gnome-system-monitor (revision 91) removed gtk-common-themes (revision 818) removed gtk-common-themes (revision 1122) removed mailspring (revision 368) removed obs-studio (revision 439) removed phpstorm (revision 98) removed robo3t-snap (revision 3) removed telegram-desktop (revision 753) removed
After cleaning up old snaps revisions, there are far less loop devices now:
[~]$ df -h Filesystem Size Used Avail Use% Mounted on udev 3,9G 0 3,9G 0% /dev tmpfs 787M 2,1M 785M 1% /run /dev/sda3 140G 108G 26G 82% / tmpfs 3,9G 87M 3,8G 3% /dev/shm tmpfs 5,0M 4,0K 5,0M 1% /run/lock tmpfs 3,9G 0 3,9G 0% /sys/fs/cgroup /dev/loop2 148M 148M 0 100% /snap/obs-studio/525 /dev/loop0 152M 152M 0 100% /snap/arduino-mhall119/5 /dev/loop10 89M 89M 0 100% /snap/core/7270 /dev/loop13 4,2M 4,2M 0 100% /snap/gnome-calculator/406 /dev/loop15 111M 111M 0 100% /snap/robo3t-snap/4 /dev/loop11 36M 36M 0 100% /snap/gtk-common-themes/1198 /dev/loop25 225M 225M 0 100% /snap/polarr/9 /dev/loop26 1,0M 1,0M 0 100% /snap/gnome-logs/61 /dev/loop32 95M 95M 0 100% /snap/telegram-desktop/818 tmpfs 787M 4,1M 783M 1% /run/user/1000 /dev/sda1 73G 55G 18G 76% /media/peter/Windows /dev/loop34 194M 194M 0 100% /snap/mailspring/374 /dev/sdb1 932G 643G 290G 69% /media/peter/Dane /dev/loop16 55M 55M 0 100% /snap/core18/1049 /dev/loop20 265M 265M 0 100% /snap/phpstorm/104 /dev/loop21 3,8M 3,8M 0 100% /snap/gnome-system-monitor/95 /dev/loop27 15M 15M 0 100% /snap/gnome-characters/292 /dev/loop35 141M 141M 0 100% /snap/gnome-3-26-1604/90 /dev/loop33 150M 150M 0 100% /snap/gnome-3-28-1804/63 /dev/sdc1 1,8T 1,1T 659G 63% /media/peter/Data2
But for day to day usage it is still not like in the old days
when df command were simply showing disks usage...
I've found solution on
Clinton's website (not sure if he was president), that
basically creates alias for df command. The alias
will hide all loop/tmp devices keeping only what's important. To
get the whole list of block devices including loop devices and
tmpfs use df with sudo.
Creating Alias for df
The alias will exclude squashfs and
tmpfs file systems from df output. To
exclude file system by type, the -x parameter can be
used. Depending on your linux distribution, you might have
.bash_aliases file or .bashrc in your
home directory. It is preferred to add aliases, well to
.bash_aliases:
echo "alias df='df -h -x squashfs -x tmpfs -x devtmpfs'" >> ~/.bash_aliases
After adding alias it is not available until bash is restarted.
You can simply call bash after adding alias to make
it active. The output of aliased command:
[~]$ df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 140G 108G 26G 82% / /dev/sda1 73G 55G 18G 76% /media/peter/Windows /dev/sdb1 932G 643G 290G 69% /media/peter/Dane /dev/sdc1 1,8T 1,2T 568G 68% /media/peter/Data2
