Always refer to the MARS user documentation for up to date changes to the MARS Service.
The MARS service grants users access to several hundred Petabytes of data on a mix of disk and tape storage.
It is important when accessing data inside MARS that we access the data in the most resonable way as doing this can help reduce wait times for our requests and for others.
As detailed in the MARS Web page, users can use the MARS Catalogue to build a request to submit to MARS.
Users can either request data via the catalogue or copy the output into a text file and submit it to the mars command for retrieval.
Regardless of how you will download the data, it is always best to use the Catalogue's
'Estimate Download Size' facility to check that the download you want to make is a reasonable request that is not going to sit in the queue for a long time
Users of MARS inside ECMWF will know this as the MARS LIST command.
The response of the 'Estimate Download Size' command can aid users in making informed decisions about their requested data.
Data is dispersed across tapes, usually depending on the dates.
A user requesting data over many tapes is likely to wait longer as the system has to load data from all of the tapes in order to return the data.
A user requesting data only on one tape can request several different requests as long as they are on different tapes
page under construction ------------------------------
ask Chris about this page?
should users interrogate the MARS system before submitting a request? etc...