[Vagnekman-users] new flashnews

[support at pdc.kth.se]

2013-02-25 at 15:55
On Wednesday, the 27th of February, the file system Klemming,
/cfs/klemming, will be upgraded to new hardware/software. This
requires that all data in the current file system be copied to
the new one. Since the copying will take days, to minimize the
amount of time that files are inaccessible to users and
downtime for the computional resources, we have decided to do
the copying with all systems on-line for most of that time. At
10AM all systems mounting Klemming will have at least a couple
of hours of downtime to switch to the new, empty, file system
and we will start copying the data from the old system to the
new. We will copy user by user, and as soon as a users files
show up in the new file system, that user can start to queue up
jobs again, which can be started by PDC staff manually. Since
we expect the number of files to be one of the most limiting
factors for the speed of the copying, we will start with the
users with the fewest files relative to their amount of data.
To minimize the total time for the copying, all users are asked
to go through their files in Klemming again and delete all
unnecessary data before the copying starts. Users who also want
to move data out of Klemming should remember to do so using the
transfer nodes (currently cfs-aux-4.pdc.kth.se, more to come)
rather than the login nodes. After the copying is complete
there will be another downtime of around half a day to finalize
the upgrade. This downtime will be announced when we know when
the copying will finish, but at least 24h in advance.