Users of the Merlin6 cluster at PSI.

["Caubet Serrabou, Marc" <marc.caubet AT psi.ch>]

Dear Merlin6 users,

First of all, we would like to wish you a Happy New Year 2026 and all the best for the year ahead.

This is a short reminder of the upcoming Merlin6 downtime in connection with the PSI-wide IT maintenance and annual system test (Schaltertest) scheduled for Friday 9 January to Sunday 11 January 2026, as previously announced.

Merlin6 will be unavailable starting Friday, 9 January, at 09:00, and is expected to return to service on Sunday morning, before lunch, provided everything goes as planned.

Please make sure to take this downtime into account when planning your work and ensure that no critical jobs are running during this period.

Thank you for your understanding, and once again, best wishes for the New Year.

Kind regards,
The Merlin Admins

On 12/5/25 15:01, Marc Caubet Serrabou wrote:

Dear Merlin6 users,

In connection with the PSI-wide IT maintenance and annual system test (Schaltertest) scheduled for 10 January 2026, which was also announced in the PSIaktuell Woche 49 communication, we would like to inform you about an extended downtime of the Merlin6 cluster.

On Friday, 9 January 2026, from 09:00 onwards, the Merlin6 cluster will be unavailable to users while we perform a software stack upgrade. The main changes concern the GPFS and InfiniBand software releases, as well as a set of minor system package updates. This upgrade is required to align the GPFS client version on Merlin6 with the version needed to update the GPFS storage servers to the latest release. The storage-side upgrade itself is planned to be carried out live (without user-visible disruption) after the Schaltertest, once the new software becomes available to PSI.

The cluster will remain shut down from approximately 17:00 on Friday in preparation for the institute-wide infrastructure tests and will stay unavailable throughout Saturday, 10 January 2026, during which IT networks and other infrastructure services may be only partially accessible. On Sunday, 11 January 2026, we will complete the final checks and validation of the services. We expect Merlin6 to be fully operational again on Sunday morning, before lunch, provided no unforeseen issues arise.

We kindly ask all users to take this downtime into account when planning their work and to ensure that any running or scheduled jobs are handled accordingly. Further updates will be communicated if necessary.

Thank you for your understanding and best regards,
The Merlin Admins

Marc Caubet Serrabou
__________________________________________________

High Performance Computing & Emerging Technologies
Paul Scherrer Institut
Forschungsstrasse, 111, OBBA/230
5232 Villigen PSI
Switzerland

Telephone: +41 56 310 46 67