“Build, Ship, and Run Any App, Anywhere” is a bold statement to make but it sure does live up to it. For the past few weeks the team has been working on incorporating Docker into the UCT eResearch HPC Cluster…
We have installed GNU Octave on our clusters. From their website: “GNU Octave is a high-level interpreted language, primarily intended for numerical computations. It provides capabilities for the numerical solution of linear and nonlinear problems, and for performing other numerical …
Researchers who bother to read the Acceptable Usage Policy may have noticed there is a clause which states: Users must abide by the ratio of 2GB of RAM (memory) per allocated core. Usage of the pmem directive should also be…
This weekend we passed the 10,000,000 CPU hours mark. This is the sum total of CPU hours of all clusters our users have run jobs on since 2010: Roughly the equivalent of running a single core computer for 416,000 days…
We have installed two high memory DELL R820 servers into the 800 series. Each server has four sockets with six cores of 2.4GHz each. There are also thirty two 32GB DIMMS making up 1TB of RAM, although these memory chips …
Over the past few months we’ve been referring to a new type of scheduler that we’ve been testing. We decided to move away from PBS as MAUI is no longer being maintained. The scheduler we have selected, SLURM, is …
MPI socket vs core affinity When running a MPI job you can bind your threads to either a socket or to individual cores. There is no one best solution, the choice depends completely on your task and the way it…
Berkeley Lab Checkpoint/Restart has been installed on the SLURM cluster. This allows users to checkpoint a job, cancel it and then resume the job at a later date. The executable is started with the cr_run wrapper: cr_run /home/andy/ram.pl >> /home/andy/ramtest.out…
SLURM allows a DefMemPerCPU and a MaxMemPerCPU to be set. If a user does not set a memory limit the default will be used. This is normally set to MaxMem/NumCores. As memory is a consumable resource (SelectTypeParameters=CR_Core_Memory) MaxMemPerCPU serves not
Our current cluster, hex, runs Torque with MAUI as the scheduler. While MAUI is GPU aware it does not allow GPUs to be scheduled. In other words you can list the nodes with GPUs but you cannot submit a job …