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Ubuntu Mirror

A local mirror of the Ubuntu package archive inside the TUKE network. Faster updates without pulling data from Canada or Germany.

mirror.tuke.sk

  • Faster

    apt update and apt upgrade pull data from TUKE, not from across the world.

  • Identical to upstream

    An exact copy of the official archive including signatures. Packages are verified the same way.

  • Available anywhere

    Works from the TUKE network and from home, without VPN.

  • Over HTTPS

    The transfer is encrypted.

Address

Repository URL
Ubuntu archive https://mirror.tuke.sk/ubuntu/
Security updates https://mirror.tuke.sk/ubuntu/

Security lives on the same mirror

Unlike the Ubuntu default, where security.ubuntu.com is a separate server, here the main archive and -security share one address. A single URL is enough in your configuration.

Supported releases

Codename Version Status
resolute 26.04 LTS Current LTS
noble 24.04 LTS LTS
jammy 22.04 LTS LTS
focal 20.04 LTS Nearing end of support
questing 25.10 Interim release

The mirror also carries older releases (bionic, xenial, trusty), but those no longer receive security patches.

Do not enable -proposed

The mirror also carries -proposed branches. They contain untested packages and can break your installation on a normal system. Use only -updates, -security and optionally -backports.

Configuration

Ubuntu 24.04 changed the source list format. Pick the one matching your release. If you are not sure, check it with:

lsb_release -ds

These releases use the deb822 format in /etc/apt/sources.list.d/ubuntu.sources.

Back up the original file

sudo cp /etc/apt/sources.list.d/ubuntu.sources \
        /etc/apt/sources.list.d/ubuntu.sources.bak

Rewrite the addresses to the mirror

sudo sed -i -E 's#https?://([a-z]{2}\.)?(archive|security)\.ubuntu\.com/ubuntu/?#https://mirror.tuke.sk/ubuntu/#g' \
    /etc/apt/sources.list.d/ubuntu.sources

Refresh the package lists

sudo apt update
Alternative: write the file from scratch

If you want to be certain what the file looks like, replace it entirely. The codename is filled in automatically from the installed release:

. /etc/os-release
sudo tee /etc/apt/sources.list.d/ubuntu.sources > /dev/null <<EOF
Types: deb
URIs: https://mirror.tuke.sk/ubuntu/
Suites: ${UBUNTU_CODENAME} ${UBUNTU_CODENAME}-updates ${UBUNTU_CODENAME}-backports ${UBUNTU_CODENAME}-security
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
EOF

Careful: this discards any custom edits in the file. Back it up first.

Older releases use the classic /etc/apt/sources.list.

Back up and rewrite the addresses

sudo sed -i.bak -E 's#https?://([a-z]{2}\.)?(archive|security)\.ubuntu\.com/ubuntu/?#https://mirror.tuke.sk/ubuntu/#g' \
    /etc/apt/sources.list

The -i.bak switch saves the original as /etc/apt/sources.list.bak.

Refresh the package lists

sudo apt update

Third-party repositories are left alone

The command only changes *.ubuntu.com addresses. Lines such as archive.canonical.com, PPAs or the Docker APT repository stay unchanged, because they are not on the mirror.

If you would rather avoid the terminal:

Open Software & Updates

Press Super, type Software & Updates and open the application.

Change the download source

On the Ubuntu Software tab, open Download from and pick Other…

Enter a custom server

Click Custom Server… and enter:

https://mirror.tuke.sk/ubuntu/

Confirm with Choose Server, close the window and let Reload finish.

Check the security updates too

The graphical tool usually changes only the main archive. The -security suite may stay on security.ubuntu.com. Verify with:

grep -r ubuntu.com /etc/apt/sources.list /etc/apt/sources.list.d/

If anything shows up, fix it using the procedure for your release on the tabs above.

Verification

Check that the mirror is in use and no original address is left behind:

grep -rE 'mirror\.tuke\.sk|(archive|security)\.ubuntu\.com' \
  /etc/apt/sources.list /etc/apt/sources.list.d/ 2>/dev/null

Then confirm that apt really downloads from the mirror:

sudo apt update

What success looks like

The output shows lines starting with Hit: or Get: pointing at https://mirror.tuke.sk/ubuntu, ending with Reading package lists... Done and no errors.

Reverting to the original settings

sudo mv /etc/apt/sources.list.d/ubuntu.sources.bak \
        /etc/apt/sources.list.d/ubuntu.sources
sudo apt update

sudo mv /etc/apt/sources.list.bak /etc/apt/sources.list
sudo apt update

Common problems

Certificate verification failed

The system has outdated CA certificates, or the clock is wrong.

sudo apt install --reinstall ca-certificates
timedatectl

If the time is significantly off: sudo timedatectl set-ntp true

The repository ... does not have a Release file

Usually a typo in the address, or a codename the mirror does not carry.

Check that the address is exactly https://mirror.tuke.sk/ubuntu/ and that the codename is in the list of supported releases.

apt update works, but installs still download from the internet

You changed only one of the files. Search all of them:

grep -r ubuntu.com /etc/apt/sources.list /etc/apt/sources.list.d/
Do PPAs and third-party repositories work?

No. The mirror carries only the official Ubuntu archive. PPAs, archive.canonical.com, Docker and similar repositories keep downloading from their own servers. That is expected and nothing needs changing.

Does it work on ARM (arm64) machines?

The mirror carries the main archive, not ubuntu-ports. On architectures served by ports.ubuntu.com, keep the original configuration. Virtual servers in TUKE Cloud are x86-64, so this does not apply to them.

Next steps

  • Ubuntu

    Releases available in TUKE Cloud and first steps after creating a VM.

    More info

  • Request a VM

    Create an Ubuntu server in the Cloud Portal.

    Guide