The CMS Tier-2 was installed at Bates in 2009 as part of the High Performance Research Computing Facility (HPRCF), and look how far it got us. One of the cornerstones of the computing center is of course the chiller which ensures healthy operating conditions for our large number of compute servers. After long service the core chiller has started to show its age and it is time to replace the old. This has been a long time coming and finally the day has arrived and we are now in downtime to remove the old and replace it with a new chiller.
This is not an easy operation when you have to cool away the heat produced in up to 70 racks which are each designed to cool away up to 12 kW through its water-cooled backdoor, which amounts to nominally 840 kW. The chiller was custom designed and took over half a year to produce. The original plan called for a 3 months installartion phase which luckily we havbe been able to reduce to 3 weeks. There is a hope to be able to switch the Tier-2 back on after shorter amount of time but this is to be seen. Custom installation can easily take longer than you think.
During the Tier-2 downtime it is though possible to run the central switch and the row of UPS racks, because even without the chiller the room has some cooling capacity. This will allow the Tier-2 team to continue to develop the new storage system for the Tier-2: the cephFS based system with completely new hardware.
First pictures of the drainage that has been completed have emerged.
It looks like new pump(s) will replace the old one?! We will be watching this.
The pictures are all courtesy of our on-site photographer Paul Acosta.