[Vagnekman-users] new flashnews

[support at pdc.kth.se]

2013-02-10 at 19:20
On Friday, the 15th 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 up to 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 running jobs again. 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 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 a few hours to finalize the upgrade. This downtime will be announced when we know when the copying will finish, but at least 24h in advance.