Just to chip in with the usual comment: don't forget that for T2
analysis use, you'll need the array to sustain significant bandwidth
to the CPU farm. This might influence your choice of technology for
both hardware and software. I would think for a system this large,
you need to budget from the start for a serious quality SAN or
There are certainly vendors who can supply all this; they often have
three-letter names. We are testing a 'turnkey solution' from IBM at
Bristol, running GPFS+StoRM, but it's apparent that there will still
be quite a lot of work to do to keep it running - probably enough to
keep a couple of people busy.
If you want more details of our experience so far, you could talk to
Jon Wakelin / Winnie Lacesso at Bristol? If you want an idea of how
much it cost, give me a call. You might want to be sitting down at
the time 8-).
On 18 Oct 2006, at 17:24, Simon George wrote:
> I have a couple of questions regarding our SE at RHUL which I hope
> you can help me with.
> 1) Hopefully this is the easy one: does someone know why RHUL is
> reporting zero disk space in our DPM on http://www.gridpp.ac.uk/
> - is it just because our site is in down time at the moment?
> 2) The plans we have based on our SRIF3 budget and GridPP3 mean
> that we will have to design, procure, deploy and manage a SRM that
> rises to about 260 TB in the next few years (to get the 1:2 ratio
> with 500kSI2k).
> I notice from the disc status page that the largest DPM is
> currently 18 TB (at QMUL). This is a massive step up in size and I
> am pretty sure that our current setup does not scale to that size,
> in terms of availability and maintenance effort if not performance.
> Based on our current system I could buy 38 7TB (net) RAID6 systems
> to set up as DPM pool nodes. Has anyone got any better advice? I
> was wondering about things like SAN storage or multi-way SCSI disk
> systems hooked up to redundant pool nodes, redundant head nodes,
> etc. but I have no experience of this sort of stuff - neither
> performance, cost, practicalities, etc. Is DPM still the right SRM
> for this scale?
> Anyone found a vendor who can provide a complete solution for
> something like this?
> I imagine a lot of people will be scaling up a similar amount over
> the next few years so hopefully this is a question of general