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Hi John, I also had the impression from the discussion with ATLAS a while ago that they were surprised that our SEs could not be regarded as permanent, high quality, backed up storage. And I also drew the conclusion (as I think did everyone in London Tier2) that the recommended way to flag a SE which is not backed up and could go down for a long time if there was a failure (due to limited manpower at the site) was "volatile". If several of us thought this then there must be something in it, even if it is misguided. To answer you Q: we don't think our SEs are less reliable than everyone else's. Rather, we think other people are are not necessarily advertising the true nature of their site. A Tier1 SE is so different to what a Tier2 site can provide. Some sites my have better support and facilities than others. btw This was in addition to the discussion with ATLAS about whether sites could delete old files. I think we do need ways to distinguish between the differing qualities of SEs. I know for ATLAS, long term availability and uptime are important factors. Disk vs tape (access time) is also important. The way forward should be a quick discussion between sites and experiments of how they would like SEs to be described, then update the Glue Schema, document it and we will fill it in. If there is no forum for this, please set one up! Cheers, Simon --------------------------------------------------------------------------- Simon George, Dept of Physics, Royal Holloway college, University of London Email [log in to unmask] Tel. +44 1784 41 41 85 Fax. +44 1784 472794 On Thu, 6 Oct 2005, Gordon, JC (John) wrote: > Would either of you care to spell out why you think your systems are > more unsafe than everyone else's? > > John > > > -----Original Message----- > > From: Testbed Support for GridPP member institutes > > [mailto:[log in to unmask]] On Behalf Of William Hay > > Sent: 06 October 2005 12:36 > > To: [log in to unmask] > > Subject: Re: Reminder of the next UKI meeting - Wednesday 5th > > October 11:00-12:00 via VRVS > > > > > Hi John, > > > > > > I have declared my storage 'volatile' and I've done so not > > because I > > > delete files whenever I feel like but because I don't consider my > > > storage safe enough to be declared permanent and if > > something happens > > > I know I've done my duty warning the experiments in advance. If > > > experiments don't exploit the glue schema they should. > > That's why we > > > have an information system. > > > > > > cheers > > > alessandra > > > > Ditto. > > > > William Hay, UCL-CCC Site Administrator, Information Systems, EISD,UCL > > >