Is snap safe to use? Snaps run in a sandbox, but classic snaps don't — how do I know what I'm installing?

Strict snaps are sandboxed via AppArmor and seccomp. Classic snaps have full host access, so stick to well-known publishers (Canonical, JetBrains, Microsoft, etc.) for those. Always run 'snap info ' to check the publisher and confinement type first.

Why does my snap application update itself without asking me?

Snapd refreshes snaps automatically four times per day by default. You can restrict this to a specific time window using 'sudo snap set system refresh.timer' or hold individual snaps with 'sudo snap refresh --hold'.

What is the difference between a snap channel track and risk level?

A track targets a major version line (e.g. '20' for Node.js 20), while the risk level — stable, candidate, beta, or edge — reflects how tested that release is. Most users want 'latest/stable'.

Can I install the same application from both snap and apt?

Yes, but they are independent installations that may conflict in the application menu or share config files unexpectedly. It is usually cleaner to pick one source and stick with it per application.

Why does /var/lib/snapd/snaps keep growing?

Snapd retains the last two revisions of each snap by default to enable rollback. Remove old revisions manually with 'sudo snap remove --revision= ' or set 'sudo snap set system refresh.retain=2' to cap retention.

How to Use Snap on Linux

Snap is Canonical's cross-distro package format. A snap bundles an application with its dependencies into a single compressed image, runs in a sandboxed environment, and updates automatically. You'll find it pre-installed on Ubuntu, and it's available on most other major distributions. This guide covers installing and configuring snapd, finding and installing snaps, understanding channels and confinement, controlling update schedules, and cleanly removing snap when you no longer want it.

Installing snapd

Ubuntu 18.04 LTS and later ship snapd by default. On other distros you need to install it first.

Debian / Ubuntu

sudo apt update && sudo apt install snapd

Fedora / RHEL / Rocky

sudo dnf install snapd
sudo systemctl enable --now snapd.socket
sudo ln -s /var/lib/snapd/snap /snap

The symlink is required so that classic-confined snaps can find their expected path. Log out and back in (or reboot) after creating it.

Arch Linux

sudo pacman -S snapd
sudo systemctl enable --now snapd.socket

Alternatively install snapd from the AUR if it is not yet in the official repos for your mirror snapshot.

Verify snapd is running

sudo systemctl status snapd

You should see active (running). Also confirm the base snap is present:

snap list

Output will vary but will show at minimum core20 or core22 and snapd itself.

Finding and Installing Snaps

Searching the store

snap find "video editor"

This queries the Snap Store and returns matching package names, versions, and short descriptions. You can also browse snapcraft.io/store in a browser.

Installing a snap

sudo snap install vlc

Most snaps install in strict confinement by default — the app is sandboxed and has limited access to the host system.

Classic confinement

Some developer tools (compilers, IDEs, shells) need broad filesystem access that the standard sandbox prevents. These use classic confinement and require the --classic flag explicitly:

sudo snap install code --classic

Classic snaps are not sandboxed. They behave like traditionally installed software, so only install classic snaps from publishers you trust. The store flags which snaps require classic; you cannot pass --classic to a strict snap — snap will reject it.

Getting snap details before installing

snap info vlc

This shows the publisher, available channels, installed version, and confinement type. Always worth checking before installing an unfamiliar package.

Understanding Channels

Every snap is published across one or more channels. A channel is a combination of a track and a risk level:

Track — usually a major version series, e.g. latest or 7
Risk level — stable, candidate, beta, or edge

The default channel is latest/stable. To install from a different channel:

sudo snap install node --channel=20/stable --classic

To switch a snap you already have installed to a different channel:

sudo snap refresh vlc --channel=latest/beta

Switch back to stable when you want the production release:

sudo snap refresh vlc --channel=latest/stable

snap info <name> lists all available channels and the version published to each.

Managing Refresh (Update) Schedules

By default snapd checks for updates four times per day and applies them automatically — even while the app is running (a new revision is prepared and applied on next launch). This is useful for security, but can be disruptive on metered connections or production systems.

Check the current refresh timer

snap get system refresh.timer

Restrict updates to a maintenance window

The following example restricts automatic refreshes to Sunday between 02:00 and 04:00:

sudo snap set system refresh.timer="sun,02:00-04:00"

Hold updates for a specific snap

Available since snapd 2.58. This pauses automatic refreshes for a named snap for up to 90 days:

sudo snap refresh --hold=30d vlc

Hold all snaps temporarily

sudo snap refresh --hold

The hold expires after 90 days maximum. This does not prevent security-critical refreshes that Canonical marks as urgent.

Trigger a manual refresh

sudo snap refresh

Refreshes all installed snaps immediately. To refresh a single snap:

sudo snap refresh vlc

View refresh history

snap changes

Useful Day-to-Day Commands

Task	Command
List installed snaps	`snap list`
See all revisions on disk	`snap list --all`
Revert to previous revision	`sudo snap revert vlc`
Disable a snap (keep installed)	`sudo snap disable vlc`
Re-enable a snap	`sudo snap enable vlc`
Remove a snap	`sudo snap remove vlc`

Snapd keeps the two most recent revisions on disk by default to allow rollback. Old revisions consume space in /var/lib/snapd/snaps/. Remove old revisions manually:

sudo snap remove vlc --revision=123

Completely Removing Snapd

Some users prefer to remove snap entirely — for example on Ubuntu where it conflicts with preferred apt-native packages. Do this carefully; removing snapd also removes all installed snaps and their data.

Remove all installed snaps first

snap list | awk 'NR>1 {print $1}' | xargs -I{} sudo snap remove {}

Remove snapd on Debian / Ubuntu

sudo apt purge snapd
rm -rf ~/snap /snap /var/snap /var/lib/snapd /var/cache/snapd

On Ubuntu, apt may reinstall snapd as a dependency of other packages (e.g. gnome-software). Pin it to prevent that:

cat <<'EOF' | sudo tee /etc/apt/preferences.d/no-snapd
Package: snapd
Pin: release a=*
Pin-Priority: -1
EOF

Remove snapd on Fedora / RHEL / Rocky

sudo systemctl disable --now snapd snapd.socket
sudo dnf remove snapd
sudo rm -rf /var/lib/snapd

Remove snapd on Arch

sudo systemctl disable --now snapd snapd.socket
sudo pacman -Rs snapd

Troubleshooting

Snap command not found after install

The /snap/bin directory may not be in your PATH yet. Log out and back in, or source your profile:

source /etc/profile.d/snapd.sh

Snap takes a long time to launch

First launch mounts the squashfs image — subsequent launches are faster. If slowness persists, check whether the snap is running on a mechanical disk; snaps on HDDs mount noticeably slower than on SSDs. Also confirm AppArmor is loaded:

sudo aa-status | grep snap

Classic snaps fail on Fedora with "mount namespace" errors

Ensure the symlink exists and that you have rebooted after creating it. SELinux can also block classic snaps on Fedora; check sudo ausearch -m avc -ts recent for denials and consider the snapd SELinux policy package:

sudo dnf install snapd-selinux

Disk space growing in /var/lib/snapd/snaps

Each snap revision is a separate squashfs file. Use snap list --all to see old revisions and remove them individually, or set the retention count:

sudo snap set system refresh.retain=2