2009/10/21 David Ambrose-Griffith <[log in to unmask]>:
> The only machine we virtualised but had second thoughts about was our
> DPM headnode, but we don't know how the site would perform with a modern
> real DPM headnode either (as the headnode it replaced was very old)
>
>
To weigh in on this matter: DPM head nodes, just like WMS/LB nodes,
can (depending on the pattern of access to them) require quite a lot
of disk io to the underlying database. This is mostly ameliorated by
the changes in data size and distribution made by the big VOs, but if
you were worried about anything, it would be about that database. It
may be worth considering a separate node with the database on it, to
avoid the potential problems in the first place (especially if you
have big storage).
I'm not sure how this translates to advice on StoRM, which I know
you're planning on moving to at Bristol, Winnie. (It does need to keep
some things in a database, but it's much lighter than DPM/dCache style
solutions).
Sam
>
>
>
> --
> David Ambrose-Griffith - [log in to unmask]
>
> Assistant Systems Programmer,
> IPPP, Department of Physics, Durham University,
> Science Laboratories, South Road, Durham, DH1 3LE
> Direct Dial: +44 (0)191 3343704
> Office: +44 (0)191 334 3811
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