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Migrating your account to Cirrus EX4000

This section covers the following questions:

  • When will I be able to access Cirrus EX4000?
  • Has my project has been migrated to Cirrus EX4000?
  • How much resource will my project have on Cirrus EX4000?
  • How do I set up an account on Cirrus EX4000?
  • How do I log into Cirrus EX4000 for the first time?

Tip

If you need help or have questions on this migration process, please contact the Cirrus service desk

When will I be able to access Cirrus EX4000?

We anticipate that users will have access sometime in the first two weeks of December 2025 but this date is subject to change based on progress with setting up the new system. We will update the date on these pages and in emails to all users.

Has my project been migrated to Cirrus EX4000?

If you have an active Cirrus CPU allocation beyond 31 Dec 2025 then your project will very likely be migrated to Cirrus EX4000. If your project is migrated to Cirrus EX4000 then it will have the same project code as it had on old Cirrus.

Some further information that may be useful:

  • If your project code begins with i or d then you are a member of an industrial project or a Director's Time project, these projects will be contacted individually to discuss arrangements. Please speak to your project leader or PI in the first instance.

How much resource will my project have on Cirrus EX4000?

As on the old Cirrus CPU partition, the unit of allocation on Cirrus EX4000 is core hours (coreh). Your initial allocations on Cirrus EX4000 will have the same number of coreh as old Cirrus allocations.

How do I set up an ARCHER2 account?

Once you have been notified that you can go ahead and setup a Cirrus EX4000 account you will do this through SAFE. The URL for SAFE is:

Once you have logged into SAFE, you will need to complete the following steps before you can log into Cirrus Ex4000 for the first time:

  1. Add Cirrus EX4000 access to your current Cirrus account
  2. (Optional) Create a new SSH key pair and add it to your ARCHER2 account in SAFE
    1. See: SSH key pairs (ARCHER2 documentation)
    2. If you do not add a new SSH key to your Cirrus EX4000 account, then your account will use the same key as your old Cirrus account

How do I log into Cirrus EX4000 for the first time?

You will log into Cirrus EX4000 in the same way as you logged in to old Cirrus using SSH to access login.cirrus.ac.uk using an SSH key pair and TOTP. Your TOTP will be the same as it was on old Cirrus. If you have issues, the Cirrus documentation covers logging from a variety of operating systems along with troubleshooting tips:

If you are still having issues after following the documentation and troubleshooting tips, please contact the Cirrus service desk