As of 23 March, the Climate Data Store (CDS) and Atmosphere Data Store (ADS) are the first two user facing services operationally supported from our new Data Centre in Bologna. Following that successful migration, we would like to update you on the next steps in the transition to the Bologna Data Centre.

We are now approaching a phase when some degradation of the services provided by the Data Handling System (DHS), the Meteorological Archival and Retrieval System (MARS) and the ECMWF's File Storage system (ECFS), is to be expected and may impact some of our Climate Data Store (CDS) and Atmosphere Data Store (ADS) data users. This is because some of the data made available from the CDS and ADS are served from tapes in the ECMWF MARS system.

The ECMWF Data Handling System (DHS) Move, causing 28 days of reduced MARS and ECFS service, is expected to start in mid-June 2022. A first short period of disruption (dry-run) occurred on 5 April 2022. As announced here previously, the second dry-run with reduced MARS and ECFS service for 12-48 hours is scheduled for 26-28 April 2022. Dry-runs are necessary to facilitate simulations of the DHS move period to ensure that our operational requirements can still be achieved. The results of these simulations will allow us to give you a more precise date for the start of the physical move.

ADS data users should expect that the following ADS datasets served from MARS tapes and the following CDS datasets served from MARS tapes will not be accessible during this second dry-run. Users may still submit ADS data requests which will remain in the queue until data access is resumed.


> Click here to see the list of affected ADS datasets (MARS external, shown in Red) 


The information above is based on current expectations. For more details and to get notified about further updates and changes, please “Watch”our dedicated confluence space. We will also update this announcement should the dates of the dry-runs change and therefore recommend our users to "Watch" this page also.

Thank you for your patience during this significant migration to our new data centre which will enable exciting scientific developments and an overall better service to all ECMWF users.

ECMWF Support