LFC problems over night

There was a problem overnight at the RAL Tier1 caused by the failure of a network switch stack. This affected a
mixture of disk servers and other grid services. The problem started at around 00:30 local time (=UTC) this
morning Friday 18th March and the network issue was resolved around 03:30 by on-call staff.

Some systems (two out of three lfc front ends and two out of four FTS front end machines) appeared problematic
after the network had been resolved. These systems have now been checked this morning and are running OK.

Because of these problems if you were running grid jobs in the UK overnight, they may have failed when trying to download their input files or register their output on the grid. If you try again now they should work.