CERN Accelerating science

CERN's 64 node IBM SP2 machine was delivered at the end of 1994 and became the heart of the CERNSP complex. This complex included an IBM SP1 machine and also a cluster of 21 independent IBM PowerPC workstations. The CERNSP complex provided a number of different services:

• the CERNSP interactive service,
• the public batch service, with LoadLeveler as the batch scheduler,
• the PaRC service for engineers, and
• disk, tape and network services.

The introduction of these Unix based services during 1995 enabled us to end the expensive mainframe based VM/CMS services during 1996. However, the arrangements under which the SP2 was purchased came to an end in 1997 and so the SP2 became the expensive system which had to be replaced.

The SP2 machine was extensively reconfigured during the 1997/1998 shutdown and maintenance cover ended for all except the disk and tape server systems. During this year, the user services have been replaced as follows.

• The RSPLUS service, based on 15 twin-CPU PowerPC workstations, took over as the main public interactive service at the beginning of March.

• An RSBATCH service was introduced running on 15 single CPU PowerPC workstations (about 4 times faster than the SP2 nodes) with LSF as the batch system. The older PowerPC nodes of the SP2 complex have now been migrated to the RSBATCH system and this now offers substantially more capacity than was available on the CERNSPB public batch service.

• A cluster of powerful Digital Personal Workstations with ALPHA CPUs was installed to support PaRC applications, although 3 PowerPC systems are also available for AIX based applications.

These replacement services are all running successfully and we will, therefore, definitively stop all user services on the SP2 and SP1 during the forthcoming annual shutdown. Replacement disk and tape servers are on order and we expect the SP2 system to be shutdown completely by the end of January 1999.