We are moving all IT documentation away from CS Department's pages to University's wiki.  Please see wiki page https://wiki.helsinki.fi/display/it4sci/Old+ukko+cluster+from+2010

Computer Science Department's high performance cluster, Ukko, is available to all department's users. You can check the list of nodes and their status and load from http://www.cs.helsinki.fi/ukko/hpc-report.txt. Public nodes are available using CS user accounts and work exactly like CS department's interactive Linux servers.

The nodes are named from ukko001.hpc.cs.helsinki.fi to ukko240.hpc.cs.helsinki.fi. They can be accessed from inside university's network and from university's openVPN service with ssh.

Sometimes the nodes need to be rebooted for software or firmware updates. Reboots are scheduled to happen during workdays, between 12:00 and 16:00, one node at a time and with five minute intervals, so that only few nodes should be unavailable at any given time (however sometimes a reboot takes longer than 5 minutes).

• Ukko nodes from ukko001 to ukko048 are rebooted on Mondays
• Ukko nodes from ukko048 to ukko096 are rebooted on Tuesdays
• Ukko nodes from ukko097 to ukko144 are rebooted on Wednesdays
• Ukko nodes from ukko145 to ukko192 are rebooted on Thursdays
• Ukko nodes from ukko193 to ukko240 are rebooted on Fridays

The reboot schedule is available from the hpc-report page. If you have a long running job, which would be stopped by a reboot, please contact itsupport@cs.helsinki.fi so that the reboot can be canceled. However, try to avoid starting long running jobs, which would be stopped by a reboot.

The cluster has 240 Dell PowerEdge M610 nodes. All nodes have 32GB of RAM and 2 Intel Xeon E5540 2.53GHz CPU:s. The CPU:s have 4 cores, so one node has a total of 8 cores. The cores are using hyperthreading so there can be a total of 16 threads running at the same time. All nodes have two bonded 10Gbit/s network interfaces.

The cluster has a shared NFS directory available at path /cs/work. The old /cs/taatto share is now reserved for legacy users only and will be mounted readonly 14.9.2015.  Personal and group subsirectories can be created at /cs/work on request. There is also directory /cs/work/scratch where everyone has write access. Please remember that old files will be removed from /scratch/ directory to reclaim disk space after 60 days of no changes.

The /cs/work share is also available in interactive host melkinkari.cs.helsinki.fi, which is accessible directly from the internet through ssh (and therefore through sftp and rsync too). 

Please, remember to remove your unused files.

Since 1.12.2011 there are also memory usage limits (30 GiB) and process number limits (256) enabled by default, just to prevent accidental crashes of nodes. These are only soft limits: they can be overridden from the command line with the ulimit shell builtin command. Please be careful with your processes and remember that the cluster has other users too!