Cirrus service news

Cirrus Migration to EPCCFS storage

14 Sep 2026

The current /work storage is coming to its end of life so on Wed 16 Sep 2026 weare moving to new storage mounted on Cirrus login and compute nodes as /epccfs.

There will be a full maintenance session (starting at 09:00 BST on Wed 16 Sep 2026) with no jobs running on compute nodes for this switch. During this maintenance session, the following high level steps will be followed:

All jobs Pending in the queue will be deleted
This step is necessary as jobs in the Pending queue before the switch will expect to be able to write to /work. As this will not be possible after the switch, any pending jobs would fail.
Current /work storage will be changed to read-only mode
/epccfs storage will be made available in read/write-mode
Final testing of /epccfs
Service returned to users

The current /work storage will remain available in read-only mode until at least 21 Nov 2026 for users to copy over any data they wish to access/keep on the new /epccfs storage.

Expanded Cirrus available to users

04 Aug 2026

In March 2026 UKRI announced the first phase of UK National Compute Resources (NCR) that will provide high performance computing facilities (HPC) to support research across the country.

Cirrus is one of the initial set of six NCRs and is the only one that is already up and running and supporting researchers. As part of the UKRI investment, Cirrus has more than doubled in size.

The expansion added 384 standard memory nodes to the existing 256 nodes (192 standard memory and 64 high memory nodes) taking the system up to 640 compute nodes in total and 184,320 CPU cores all connected by HPE Cray Slingshot 11 interconnect. The new nodes are already available to Cirrus users.

Cirrus - a UK National Compute Resource

09 Mar 2026

UKRI recently announced the first phase of UK National Compute Resources (NCR) that will provide high performance computing facilities (HPC) to support research across the country.

Cirrus is one of the initial set of four NCRs and is the only one that is already up and running and supporting researchers. As part of the UKRI investment, Cirrus will be more than doubling in size over the next few months. Cirrus will compliment the announced next national supercomputer which, like Cirrus, will also be operated by EPCC, the first UK National Supercomputing Centre.

Cirrus EX4000 service start

08 Dec 2025

We are pleased to announce that the new Cirrus EX4000 service has now started. Jobs finishing after 0800 GMT today (Mon 8 Dec 2025) will be charged against budgets.

You should now use “login.cirrus.ac.uk” to access the system rather than “preview.cirrus.ac.uk”. The preview address will be removed at some time in the future. If you previously had a entry in your “known_hosts” file for the old Cirrus login nodes, you may need to manualy remove this before you can login. An example of the error and how you can fix it are included at the bottom of this message.