# Computing environment

## Puhti compute services decommissioned, 31.7.2026

Compute services in Puhti have been decommissioned as of 31 July 2026 at 12:00 EEST.
No new jobs will be accepted or executed on its compute nodes.

Mahti's compute services are being decommissioned 31 August 2026.

Puhti and Mahti login nodes and storage services are planned to remain available until 15 October 2026.

## Roihu FAQ and data migration instructions updated, 11.6.2026

The [Roihu FAQ](../faq/roihu.md) and [data migration instructions](../tutorials/roihu-data-preparation.md) have
been updated with the latest information for the transition from Puhti
and Mahti to Roihu. Roihu is scheduled to become generally available during end of June 2026.

Puhti and Mahti will be fully decommissioned by mid October, after Roihu becomes available, so users
should start preparing their data for migration. We recommend reviewing what data
needs to be moved, deleting unnecessary files and ensuring that important data is
moved, or saved, before Mahti and Puhti are decommissioned.

Puhti and Mahti storage services will be fully inaccessible after October 15th 2026.

See the updated instructions:

* [Roihu FAQ](../faq/roihu.md)
* [Roihu data preparation instructions](../tutorials/roihu-data-preparation.md)

## Puhti and Mahti web interface updated to release 33 and 17, 11.6.2026

* The MATLAB version can now be selected.
* Jupyter for Courses now has an option to reset the course material.
* VSCode now has an option to re-open the last opened workspace.
* Open OnDemand updated to 4.1.5.

## Puhti and Mahti web interface updated to release 32 and 16, 25.2.2026

* [Jupyter with an R kernel](../../computing/webinterface/r-jupyter.md) is now available on Mahti.
* VSCode updated to 1.111.0.
* Newer MLflow versions are now supported in the MLflow app.
* The maximum number of cores for the Compute node shell on Mahti has been increased to 12.
* Open OnDemand updated to 4.0.10.

## Puhti and Mahti web interface updated to release 31 and 15, 3.12.2025

* The File Deletion Explorer tool now exports correctly when multiple projects are used (Puhti).
* Default MATLAB memory has been increased to 8GB (Mahti).
* Open OnDemand updated to 4.0.8 (Mahti).

## Puhti web interface updated to release 30, 5.11.2025

* A new File Deletion Explorer tool has been added for testing, see more information [here](../../support/tutorials/clean-up-data.md#using-lcleaner-and-the-web-interface-to-check-which-files-will-be-automatically-removed).
* Default MATLAB memory has been increased to 8GB.
* The Allas Swift integration now generates correct storage URLs.
* Open OnDemand updated to 4.0.8.

## Instructions on moving data between CSC supercomputers improved, 30.10.2025

We have improved our instructions on moving data directly between CSC
supercomputers using utilities such as [scp](../../data/moving/scp.md) and
[rsync](../../data/moving/rsync.md). Notably, now that SSH keys are required for
authentication on CSC supercomputers, we've added instructions on how to enable
SSH agent forwarding
[on Linux/macOS](../../computing/connecting/ssh-unix.md#ssh-agent-forwarding) and
[on Windows](../../computing/connecting/ssh-windows.md#ssh-agent-forwarding). This
is a requirement for being able to directly connect between CSC supercomputers in
order to, for example, transfer data efficiently.

## Puhti and Mahti web interfaces updated to release 29 and 14, 2.10.2025

* CPU, GPU, storage and cloud billing units are now visible in the web interfaces.
* The login method will no longer default to Haka login and can instead be freely selected.
* MATLAB has been added to Mahti, but requires a license.
* MATLAB version selection has been added to Puhti.
* MATLAB on Puhti now allows using non-CSC licenses from your MathWorks account.
* VSCode updated to 1.104.1.
* TurboVNC updated to 3.2 in the Desktop app.
* Rclone updated to 1.71.1
* Open OnDemand updated to 4.0.7.

## Puhti and Mahti web interfaces updated to release 28 and 13, 19.8.2025

* Rclone updated to 1.70.3
* TensorBoard now waits until it has fully launched before allowing the user to connect.
* Desktop app now uses module reset instead of module restore.
* Some security and performance improvements have been made.
* Open OnDemand updated to 4.0.6.

## Puhti and Mahti web interfaces updated to release 26 and 12, 6.5.2025

* Jobs in the web interfaces have been limited to a maximum of 16 hours to improve queueing times.
* VSCode now sets python.defaultInterpreterPath to help identifying the correct Python interpreter.
* Virtual environments in the Jupyter app now work better with some modules, e.g. geoconda.
* The email on session start option has been added to all interactive apps.
* Open OnDemand updated to version 4.0.3.

## New data cleaning policy on Puhti, 17.4.2025

On Puhti there is a process to clean (delete) old files in scratch that are not
in active use. To ensure the system remains usable, we are changing the
[cleaning policy](../../computing/usage-policy.md#disk-cleaning).

**The new policy is**:

* If project has a **scratch quota of 5 TiB or more**, cleaning will target
  files that have not been accessed (opened, read, modified) in the last **90
  days**.
* For other projects with smaller scratch quotas the cleaning policy is
  unchanged. Cleaning will target files that have not been accessed (opened,
  read, modified) in the last **180 days**.

You can use the `csc-workspaces` command to see which cleaning cycle your
projects are subject to.

## Puhti and Mahti web interfaces updated to release 25 and 11, 7.4.2025

* Mahti: [RStudio](../../computing/webinterface/rstudio.md) has been added.
* RStudio now queries available r-env version dynamically.
* VSCode updated to 1.98.2.
* Python module selection has been added to VSCode.
* Interactive app launch settings can now be saved and restored later. See [Saved interactive app settings](../../computing/webinterface/apps.md#saved-interactive-app-settings) for how to use them.
* Interactive app form labels and descriptions have been improved.
* The default amount of local disk for interactive apps has been reduced.
* The performance of the web interfaces has been improved.
* Open OnDemand updated to version 4.0.2.

## Starting April 22 2025, multi-factor authentication is required to login to web interfaces of Puhti and Mahti, 2.4.2025 <a id="mfa"></a>

**Change:** Starting April 22 2025, multi-factor authentication (MFA) will be
required to
[login to the web interfaces of Puhti and Mahti](../../computing/webinterface/connecting.md).

**Action:**  Test whether MFA is already enabled for Haka logins by your home
organization. [Please use the test page in MyCSC](https://my.csc.fi/test-mfa)
(select **Haka MFA**). It is highly preferred to use the Haka MFA of your home organization, if possible.
If Haka MFA is not enabled or if your home organization does not offer Haka,
[please activate **CSC MFA** following these instructions](../../accounts/mfa.md#how-to-activate-csc-mfa).

**Motivation:** With this change we are improving the security of our
computing, data, and cloud services.
[Read more about MFA in the blog on the research.csc.fi website](https://research.csc.fi/2025/04/02/multi-factor-authentication/).

Please contact [CSC Service Desk](../../support/contact.md) if you have any
questions or need support with activating MFA.

## Starting April 14 2025, SSH login to Puhti and Mahti will only work with SSH keys added in MyCSC, 25.3.2025 <a id="ssh-key"></a>

**Change:** Starting April 14 2025, only SSH keys added through MyCSC will
allow you to login to Puhti or Mahti with SSH. Traditional password-based
authentication and SSH keys stored in your personal `~/.ssh/authorized_keys`
file will no longer work. Note that the Puhti and Mahti web interfaces are not
affected by this change and login sessions can be launched within the web
browser as before.

**Action:** To access Puhti and Mahti login nodes with SSH, you must create SSH
keys and add your public key to MyCSC.
[See here for detailed instructions on setting up and using SSH keys](../../computing/connecting/ssh-keys.md).

**Motivation:** The purpose of implementing this change is to improve the
security of our computing, data, and cloud services. Password-based logins
are vulnerable, as are manually managed SSH keys. Implementing MyCSC key
management significantly strengthens user identity verification.

Please contact [CSC Service Desk](../../support/contact.md) if you have any
questions or need support with taking SSH keys into use.

## New Small Partition with High-Performance NVMe Storage on Mahti, 13.2.2025

Mahti has expanded its capabilities with a
[new small partition](../../computing/running/batch-job-partitions.md#mahti-cpu-partitions-with-core-based-allocation)
featuring 56 compute nodes (7168 cores), each equipped with 3500 GiB
of local NVMe storage. This partition introduces flexible CPU
core-based allocation, allowing users to reserve individual cores
rather than entire nodes. Additionally, the interactive partition has
been enhanced with 4 nodes that include the same high-capacity local
storage.

This new configuration is optimized for batch processing of small
CPU-intensive workloads that require fast local storage access. The
combination of core-based allocation and high-performance NVMe drives
makes this partition particularly suitable for data-intensive
tasks. Current Puhti users working with I/O-bound workflows may find
this new resource especially valuable for their computations.

## Puhti and Mahti web interfaces updated to release 24 and 10, 30.1.2025

* VSCode has been updated to 1.96.4.
* The accessibility statement contact info has been updated.
* MLflow now works with when using NVME again.
* Open OnDemand updated to version 3.1.10.

## Puhti and Mahti web interfaces updated to release 23 and 9, 23.10.2024

* MLflow, Tensorboard, and the Desktop app now work with newer Apptainer.
* The number of CPUs per GPU is now limited to 10.
* The link to MyCSC has been fixed.
* Puhti: The fonts in the Accelerated Visualization app have been improved.
* Open OnDemand updated to version 3.1.9.

## Puhti and Mahti web interfaces updated to release 22 and 8, 28.8.2024

* The Jupyter app launch form has been improved.
    * Module version for Python modules can now be selected using a dropdown.
    * The UI for extending the Python environment with additional packages has been simplified.
* The MLflow app launch form now lists all available pytorch module versions.
* The performance of the web interfaces have been improved.
* The Compute node shell now supports running multiple instances on the same node.
* Open OnDemand updated to version 3.1.7.

## Puhti and Mahti web interfaces updated to release 21 and 7, 13.6.2024

* VSCode updated to 1.89.1.
* Jupyter app should work better with virtual environments created outside the web interface.
* Puhti: RStudio now has R version 4.4.0 available.
* Puhti: VisIt updated to 3.3.3. Some previously missing dependencies are now installed.
* Open OnDemand updated to version 3.1.5.

## Puhti and Mahti web interfaces updated to release 20 and 6, 27.5.2024

* The Cloud storage configuration app can now configure connections to LUMI-O.

## Puhti and Mahti web interfaces updated to release 19 and 5, 10.4.2024

* The error pages for issues caused by Lustre and other issues have been improved.
* The Desktop app terminal now supports submitting Slurm jobs.
* The Desktop app terminal now uses the default $XDG_CONFIG_HOME rather than a custom location.
* Downloading directories now works correctly again.
* Accessibility statement has been updated and some accessibility issues have been fixed.
* Open OnDemand updated to version 3.1.4

## Puhti web interface updated to release 18, 5.3.2024

* Allas and IDA can now be accessed in the file browser.
* The Cloud storage configuration tool for generating access tokens to Allas is now available.
* The Desktop and Accelerated Visualization apps have been improved.
    * Accelerated Visualization now launches the same desktop as the Desktop app.
    * Applications for the Accelerated Visualization app can now be found in the applications menu in the desktop.
    * VisIt is now available in Accelerated Visualization.
    * Launching applications should be more reliable.
    * The terminal window stays open if errors occur launching applications.
    * Applications are now categorized in the menu.
* Handling of reservations has been improved.
    * Future reservations are now shown.
    * All reservations can now be used on any app regardless of partition.
    * Reservation caching has been improved to be more up to date.
    * Job time is now limited by reservation length automatically.
* MATLAB updated to r2023b.
* VSCode updated to 1.86.1.
* TensorBoard and MLflow can now use the default module versions.
* Open OnDemand updated to version 3.1.1.

## Mahti has small GPUs available for interactive work, 5.3.2024

Four (4) A100 GPUs on Mahti have been split into a total of 28 smaller GPUs with a fraction of the 
compute and memory capacity of a full A100 GPU. These a100_1g.5gb GPUs have one seventh of 
the compute power of one A100 GPU and in total 5 GB of memory. These are useful for interactive work, 
courses and for code development, and are also available via the
[web interface](../../computing/webinterface/index.md#partitions-and-resources).
[See more details here](../../computing/running/creating-job-scripts-mahti.md#gpu-batch-jobs).

## Mahti web interface updated to release 4, 27.2.2024

* GPUs (MIG) are now available in apps in the *gpusmall* partition.
* The Desktop app has been improved
    * Launching applications should be more reliable.
    * The terminal window stays open if errors occur launching applications.
    * Applications are now categorized in the menu.
* VSCode updated to 1.86.1.
* TensorBoard and MLflow can now use the default module versions.
* Open OnDemand updated to version 3.1.1.

## SSH security updates for cryptography options, 12.1.2024

Recently, a new SSH vulnerability called Terrapin (CVE-2023-48795) was published describing
weaknesses in the key exchange when using certain ciphers.
Consequently, the login nodes on Puhti and Mahti have been updated to disallow the use of the weak
ciphers: `chacha20-poly1305@openssh.com` and any EtM cipher variants.
This change was deployed on Friday 12.1.2024 around 13 o'clock Finnish time.

This change seems to have triggered many Windows OpenSSH clients to use a cipher and MAC algorithm
combination, which does not work. The result is a message saying "Corrupted MAC on input".
This is a known issue on Windows, and can be worked around
by adding explicit options for which MAC algorithms to use.

Please refer to our [FAQ page about the issue](../faq/i-cannot-login.md#why-is-my-ssh-client-saying-corrupted-mac-on-input)
for details.

## Mahti web interface updated to release 3, 12.12.2023

* Handling of reservations has been improved.
    * Future reservations are now shown.
    * All reservations can now be used on any app regardless of partition.
    * Reservation caching has been improved to be more up to date.
    * Job time is now limited by reservation length automatically.
* Jupyter for Courses now also allows specifying reservation in the course environment YAML.
* Jupyter for Courses and TensorBoard now show errors if the module or log path are left empty.
* Web interface session lifetime has been increased to 12h from the previous 8h.
* Umask is now set correctly. This affects files created using the file browser.
* The browser cache is now validated more frequently to avoid issues after updates.

## The LUMI web interface has been released, 9.11.2023

The brand new LUMI web interface has been released at [www.lumi.csc.fi](https://www.lumi.csc.fi)!
The LUMI web interface offers the same capability as the Mahti and Puhti web interfaces.
Read more in the [LUMI documentation](https://docs.lumi-supercomputer.eu/runjobs/webui/).

## Mahti web interface updated to release 2, 13.10.2023

* [MLflow Tracking](../../computing/webinterface/mlflow.md) is now available as an interactive app.
- An [Allas configuration tool](../../computing/webinterface/file-browser.md#accessing-allas-and-lumi-o) has been added for configuring a connection to Allas.
- [IDA](../../data/ida/using_ida.md) is now supported in the file browser.
- The Desktop app configuration and icons are now saved between sessions.
- VSCode updated to 1.82.2.
- Jupyter notebooks in VSCode now work.
- Usage metrics now include a description.
- Open OnDemand updated to version 3.0.3.

## Puhti web interface updated to release 17, 8.9.2023

* [MLflow Tracking](../../computing/webinterface/mlflow.md) is now available as an interactive app.
* Jupyter now has the [qiskit](../../apps/qiskit.md) module available.
* Changes in the Desktop app:
    * The desktop configuration is now saved between sessions.
    * The MATE desktop environment and single application launch has been removed.
* MATLAB updated to r2023a.
* VSCode updated to 1.80.2.

## Puhti web interface updated to release 16, 4.7.2023

* RStudio now has r-env 4.3.0 available.
* Blender updated to 3.6.0 with added support for add-on installation.
* Web interface session lifetime has been increased to 12h from the previous 8h.

## Mahti web interface available, 13.6.2023

The [web interface](../../computing/webinterface/index.md), previously available for
Puhti only, is now available also for Mahti at [www.mahti.csc.fi](https://www.mahti.csc.fi).
Apps available in the [Mahti web interface](https://www.mahti.csc.fi):

* Active Jobs
* Compute and Login node shell
* Desktop with Maestro and VMD
* Disk quotas and Project view
* File browser with [support for Allas](../../computing/webinterface/file-browser.md#accessing-allas-and-lumi-o)
* Jupyter, Julia-Jupyter and Jupyter for courses
* TensorBoard
* Visual Studio Code

## New policy on Puhti and Mahti for projects that have run out of Billing Units, 22.5.2023

In addition to limiting access to compute resources upon running out of billing
units, now also access to storage will be limited on Puhti and Mahti. Please read
[running out of Billing Units](../../computing/usage-policy.md#running-out-of-billing-units)
for more details. To give all projects time to react, the policy will be enforced
starting June 21, 2023. Please login to MyCSC to check if you have projects that
have a negative amount of Billing Units. When logging in to Puhti using ssh or
the web interface you will also receive warnings and information on how much time
remains before access is removed.

## Puhti web interface updated to release 15, 2.5.2023

* A new [Julia-Jupyter app](../../computing/webinterface/julia-on-jupyter.md) is now available.
* Visual Studio Code app has received updates.
    * Support for [Julia language features](../../computing/webinterface/vscode.md#julia-language) was added.
    * VSCode version 1.76.1 is now available.
    * Version may be selected when launching the app.
* Puhti usage metrics now include history (expand by clicking the chevron).
* Open OnDemand version updated to 2.0.32.

## Puhti web interface updated to release 14, 2.2.2023

* Xfce is now the main desktop alternative and other options are being deprecated
* Removed MOTD from the frontpage
* All terminals in the desktop now open outside the container -> should work exactly as a normal login shell
  * Host terminal has been renamed Terminal on the desktop
* Graphical Emacs now available in the desktop
* Jupyter app now accepts full path to Python interpreter, enabling direct usage of Tykky installations.
* Time left for job is now correctly calculated and displayed at the bottom of the terminal when reconnecting to a compute node shell. 

## Puhti disk cleaning policy changed, 17.1.2023

* [Usage policy](../../computing/usage-policy.md) changed, now files not accessed in **6** months are deleted in the cleaning process.

## Puhti web interface updated to release 13, 20.12.2022

* New visual style.
* A logout page now informs users about how to securely log out of Puhti web interface.

## Puhti web interface beta updated to release 12, 10.11.2022

* User authentication is now happening through OpenID Connect, which means that users
  can authenticate via Haka or CSC login. This enables Single Sign-on (SSO) between,
  e.g., the web interface and MyCSC.
* A new welcome page has been added instead of the old login page.
* The Puhti usage metrics are now visualized in a new manner.
* Open onDemand version updated to 2.0.29.

## New login nodes on Puhti, 9.11.2022

Two new login nodes, `puhti-login14.csc.fi` and `puhti-login15.csc.fi`, have
been added to Puhti and included to the round-robin DNS of `puhti.csc.fi`.
Use the command `ssh <username>@puhti-login<11-12,14-15>.csc.fi` if you need
to connect to a specific login node, e.g. `ssh kkayttaj@puhti-login14.csc.fi`.

## Puhti operating system updated to RHEL8, 5.10.2022

The operating system of Puhti has been updated from Red Hat Enterprise Linux (RHEL) 7 to RHEL 8.

* Pre-installed software and libraries as well as the documentation have been updated
* Default compiler stack is now `gcc/11.3.0`, `openmpi/4.1.4` and `intel-oneapi-mkl/2022.1.0`. [See more details.](../../computing/compiling-puhti.md)
* Note that `hpcx-mpi` has been removed and replaced by `openmpi`
* Users should recompile their own codes for the new OS
* Some older versions of applications are not available anymore

Please note that old login nodes (`puhti-login1` and `puhti-login2`) are no longer available.
The new login nodes have been renamed as `puhti-login11` and `puhti-login12`. Also, the ssh
keys of the login nodes have changed and the checksums of the new keys are:

| SHA256 checksum                             | Key                                |
|---------------------------------------------|------------------------------------|
| kk0Tar9opQ+6Gq0GWJdWVVvFEMeI6kW1DW1VOYveT5c | ssh_host_ecdsa_key.pub (ECDSA)     |
| Q2lpykI43ffs4PrRODZ/qncjUo3eyrRHc5T9yjJEwWY | ssh_host_ed25519_key.pub (ED25519) |
| WH1Ag2OQtMPZb+hj3YeH9uVMMetXpCvyNUbsdk0Qcpk | ssh_host_rsa_key.pub (RSA)         |

When logging into `puhti.csc.fi` for the first time after the RHEL8 upgrade, you will
encounter a warning saying "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!".
**This is completely expected, and you do not need to worry about it.**
The warning will disappear if you remove `puhti.csc.fi` from your `known_hosts` file.
You can run the following command: `ssh-keygen -R puhti.csc.fi` or you can remove the
offending line with your favorite text editor. The warning message will print which
line number is the problematic one.

After removing the offending line, login again as normal, check that the fingerprint that
is offered by the server matches one of the above checksums, and type "yes" to continue
connecting. After this you should be able to connect to `puhti.csc.fi` normally.

## Puhti web interface beta updated to release 10 24.8.2022

* A new [MATLAB app](../../computing/webinterface/matlab.md) has been added.
* Blender has been added to the [Accelerated Visualization app](../../computing/webinterface/accelerated-visualization.md).
* Improved form validation messages.
* Improved Jupyter app launch form.
* pytorch module now launches correctly in Jupyter app.
* Fixed Jupyter Lab not working in Jupyter for Courses.
* Updated VS Code to 1.70.1.
* Open onDemand version updated to 2.0.28.

## Puhti has been updated with additional local disks on Big Mem nodes, 6.7.2022

Fast local NVMe disks can be used to speed up single node workloads that do a lot of
read and write operations on data sets that fit on the disks. Especially small reads
and writes, and operations on a large amount of files are much faster on the local disks
than on the parallel file system. Now also the 6 nodes with 1.5 TiB of memory have been
upgraded with 5960 GiB local disks. See [Puhti technical details](../../computing/systems-puhti.md)
for a detailed list of all nodes.

## Puhti web interface beta updated to release 9 5.7.2022

* Added graphs showing Lustre usage metrics to dashboard.
* Improved web interface performance, especially during heavy Lustre load.
* Modules selected when launching apps are now shown on the active sessions page.
* Local disk must now be used when running RStudio.
* Updated VS Code to 1.66.2.
* Open onDemand version updated to 2.0.27.

## How to clean up data - automatic removal, new tools and instructions 10.6.2022

Puhti's parallel file system is filling up and hence degrading performance. We will start
to enforce a policy to remove old files. To help managing files without causing
excessive load on the system, we've updated our [tutorial on how to move, delete or archive
your data](../tutorials/clean-up-data.md).

## Puhti web interface beta updated to release 8 25.5.2022

* A new [Accelerated Visualization app](../../computing/webinterface/accelerated-visualization.md) has been added for running applications with GPU acceleration.
* Improved the main dashboard page layout.
* Improved login page layout.
* Added more visible warnings about home directory quota.
* Added CSC User guides links to all apps.
* Open onDemand version updated to 2.0.24.

## Puhti has been updated with additional local disks, 13.5.2022

Fast local NVMe disks can be used to speed up single node workloads that do a lot of read and write operations on data sets that fit on the disks. Especially small reads and writes, and operations on a large amount of files is much faster on the local disks than on the parallel file system. Now 48 nodes with 192 GiB of memory, and 12 nodes with 768 GiB of memory have been equipped with local disks that have a size of 1490 GiB. Later in 2022 all the big memory nodes with 1,5TiB of memory will be upgraded with 6 TiB disks. These are in addition to the original 40 CPU nodes and 80 GPU nodes with 3600 GiB NVMes.  See [Puhti technical details](../../computing/systems-puhti.md) for a detailed list of all nodes.

## Mahti operating system updated to RHEL8, 4.5.2022

The operating system of Mahti has been updated from Red Hat Enterprise Linux (RHEL) 7 to RHEL8.

* Pre-installed software and libraries including the documentation have been updated.
* Users should also recompile their own codes for the new OS.
* Some older versions of applications are not available anymore.

Please note that old login nodes (mahti-login1 and mahti-login2) are not available
and new login nodes also have new names, mahti-login11 and mahti-login12.
Also the ssh keys of login nodes have changed and check sums of new keys are:

| SHA256 checksum                             | Key                                |
|---------------------------------------------|------------------------------------|
| WC9Lb5tmKDzUJqsQjaZLvp9T7LTs3aMUYSIy2OCdtgg | ssh_host_ecdsa_key.pub (ECDSA)     |
| tE+1jA4Et1enbbat1V3dMRWlLtJgA8t7ZrkyIkU4ooo | ssh_host_ed25519_key.pub (ED25519) |
| 0CxM3ECpD2LhAnMfHnm3YaXresvHrhW4cevvcPb+HNw | ssh_host_rsa_key.pub (RSA)         |

When logging into mahti.csc.fi for the first time after the RHEL8 upgrade, you will
encounter a warning saying "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!".
This is completely expected, and you do not need to worry about it.
The warning will disappear if you remove mahti.csc.fi from your `known_hosts` file.
You can run the following command: `ssh-keygen -R mahti.csc.fi` or you can remove the
offending line with your favourite text editor. The warning message will print which
line number is the problematic one.

After removing the offending line, log in again as normal, check that the fingerprint that
is offered by the server matches one of the above checksums, and type "yes" to continue
connecting. After this you should be able to connect to mahti.csc.fi normally.

## Puhti web interface beta updated to release 7 23.3.2022

* [Jupyter for courses](../../computing/webinterface/jupyter-for-courses.md) app now supports creating course environments for projects.
* Added Puhti usage graphs to dashboard.
* Added cookie policy and accessibility statement pages.
* Some UI fixes and small bug fixes.
* Open onDemand version updated to 2.0.23.

## Puhti web interface beta updated to release 6 2.2.2022

* Possible to select slurm reservation for applications
* New Jupyter app for courses.
* Open onDemand version updated to 2.0.22.

## Puhti web interface beta updated to release 5

* Added new TensorBoard app for visualizing TensorFlow runs.
* When launching apps, only partitions available for the selected project are visible now.
* Rclone app has been removed.
* Open onDemand version updated to 2.0.20.

## Puhti web interface beta updated to release 4 30.11.2021 

* Can now use custom python environments for Jupyter notebooks, see [Jupyter documentation](../../computing/webinterface/jupyter.md).
* Added new **Compute node shell** app that gives a persistent shell on a compute node for commands that should not be run on login nodes.
* App cards show more information  about resource usage after job has finished (seff output)
* Can reset interactive forms to default settings
* Rclone app now alerts about missing Allas authentication
* Added terminal outside container to Desktop app
* Quota and BU warnings can now be hidden
* Open onDemand version updated to 2.0.19


## Puhti web interface beta updated to release 3 9.11.2021

* App cards show more information about resources and reason for shutting down the app to help troubleshoot issues.
* Various app improvements, especially Rclone.
* Increased timeouts for launching apps.
* Login fails now show an error message.

## Puhti web interface beta (release 2) is available 18.10.2021

An easy-to-use web interface for Puhti is now open for beta test use at <https://www.puhti.csc.fi>. The new user interface offers an easy way for new users to use Puhti, and for experienced users it makes access to some features quicker and easier. See [web interface](../../computing/webinterface/index.md) for details

## MPICH modules no longer work 4.5.2021 

As a consequence of the major network stack update done on Puhti during the service break, the MPICH installations on Puhti no longer work correctly and can not be easily fixed. Old versions of MPICH were installed as a last-resort option and they were using a communication library that has now been deprecated by the vendor. We advice you to recompile your software using either hpcx-mpi or intel-mpi. Please let us know if for some reason you can not at all work with either of the above mentioned mpi libraries.

MPICH version 3.4 with UCX support is going to be installed on Puhti later, but this will take some time.

## Slurm update and srun & behavior 4.5.2021

Running `srun prog &` on Puhti  will produce errors like  "step creation still disabled, retrying (Requested nodes are busy)" if `SLURM_EXACT=1` or `SLURM_OVERLAP=1` is not set. See <https://slurm.schedmd.com/srun.html> for details

