Friday, 29 June 2007

Lancaster Weekly Update

This week has not been fun, having been dominated by a dcache configuration problem that's caused us to fail the week's worth of SAM tests. The gPlazma plugin- the voms module for dcache, had started complaining about not being able to determine which username to map an access request to from a given certificate proxy. This problem was made worse by dcache then not falling back to use the "old fashioned" kpwd file method of doing the mapping. So users were getting "access denied" type messages. Well, all users except some, who had no problem at all, these privilaged few included my good self so diagnosing this problem involved a lot of asking Brian if it was still broke.

After some masterful efforts from Greig Cowan and Owen Synge we finally got things back up and running again. Eventually we fixed things by:

Upgrading to Owen's latest version of glite-yaim (, and installing his config script dcacheVoms2GPlasma. After some bashing and site-info tweaking this got the gPlazma config files looking a bit more usable.

Fiddling with the permissions so that the directories in pnfs were group writable (as now some users were being mapped to the sgm/prd vo accounts).

Upgrading to dcache-server-1.7.0-38.

Between all these steps we seem to have things working. We're still unsure why things broke in the first place, why gPlazma wouldn't fall back to the kpwd way of doing things or why it still worked for some and not for others. I'd like to try and get to the bottom of these things before I draw a line under this problem.

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