05 February 2008

CMS CCRC storage requirements

Since I've already talked about ATLAS tonight, I thought it might be useful to mention CMS. The official line from the CCRC meeting that I was at today is that Tier-2 sites supporting CMS should reserve space (probably wise to give them a couple of TBs). The space token should be assigned the CMS_DEFAULT space token *description*.

DPM sites should follow a similar procedure to that for ATLAS described below. dCache sites have a slightly tougher time of it. (Matt, Mona and Chris, don't worry, I hear your cries now...)

2 comments:

Brian Bockelman said...

Uh.. I wrote the requirements for the space tokens for CMS, and I think saying that dCache sites "should" use space tokens are stretching it. Most sites won't, I think. Most likely no sites in the US will be using CMS_DEFAULT.

Here's the twiki page:
https://twiki.cern.ch/twiki/bin/view/CMS/CMS-SRMv2-spacetokens

Everything a T2 site needs to know about how CMS will be using their storage is basically there. The rest is scattered throughout the twiki and in my head.

Note that the 900lb gorilla dCache site (FNAL) is rejecting space tokens outright, and CMS is fine by that.

In fact, CMS management has said basically "we're happy with any SRMv2 configuration which is functional".

Certainly at Nebraska and most other US T2 sites, we will not be touching space tokens until other VOs have shook out all the really devious bugs.

Greig A Cowan said...

I knew you were going to say that.

There was an Italian CMS guy in the CCRC meeting and he was basically leaving the decision up to the sites.