High Performance Computing

A low memory usage error indicates that much less memory is being used than is provided by the system. A typical case is running a job that uses a small amount of memory in one of the job queues that provides large memory nodes. The example below shows that large memory nodes were requested (lines 2 and 22), but the average memory usage was less than 1 percent (line 3). Given that only 5.125 gb were required, the job could easily have fit on a 32 gb node provided by the workq or checkpt queues. In this case, the load of 16 (lines 4, 17, and 23) indicates the CPU cores were fully occupied. User account information is shown in lines 30 to 39.

 1)  E132 - Low memory usage
 2)  Total physical memory per node: 258272mb
 3)  Average memory usage: 5125mb, 1%
 4)  Average CPU percent is: 1566%
 5)  Please try to better use CPU resources.
 6)
 7)  Node statistics::
 8)  Number of nodes: 1
 9)  Number of cores: 16
10)  Total physical memory per node: 258272mb
11)  Average memory usage per node: 5125mb, 1%
12)  Average memory usage per core: 320mb
13)  Average virtual memory usage per node: 5890mb
14)  Average virtual memory usage per core: 368mb
15)  Average CPU percent per node: 1566%
16)  Average CPU percent per core: 97%
17)  Average load per node: 16.09
18)  Reverified average load per node: 16.10
19)  Effective maximum load on a node: 16.10
20)
21)  PBS_job=432161.mike3 user=flast allocation=hpc_alloc04
22)  queue=bigmem total_load=16.09 cpu_hours=5.38 wall_hours=3.96
23)  unused_nodes=0 total_nodes=1 ppn=16 avg_load=16.09 avg_cpu=1566%
24)  avg_mem=5125mb avg_vmem=5890mb
25)  top_proc=flast:mothur:mike438:355M:320M:0.1hr:100%
26)  toppm=flast:mothur:mike438:410M:359M node_processes=18
27)  avg_avail_mem=222946mb min_avail_mem=222946mb
28)  reverified_avg_load=16.10
29)
30)  Name:  First Last
31)  Mail:  flast@somewhere.lsu.edu
32)  Affil: First Last
33)  Category: validation:current:01/27/2014
34)  Name:  First Last
35)  Mail:  flast@somewhere.lsu.edu
36)  Affil: First Last
37)  Category: validation:current:01/27/2014
38)  Allocations:
39)  hpc_alloc04,flast,50000.00,