A useful start in administering SGE is the qmon graphical configuration tool.
SGE is a good deal more fexible than PBS as it deals directly with hosts rather than entities like PBS queues. For instance (permissions allowing) a batch job may either be submitted to a job pool or directly to a compute node. E.g
qsub -q comp000.q myjob.shAnother powerful feature of SGE is the ability to submit "array" jobs. This allows a user to submit a range of jobs with a single qsub. For example:
qsub -t 1-100:2 myjob.shThis will submit 50 tasks (1,3,5,7,...,99). The job script knows which of the tasks it is via the $SGE_TASK_ID variable. For example a job script might look like:
#!/bin/sh TASK=$SGE_TASK_ID # Run my code for input case $TASK and output it to an # appropriate output file. cd /users/nrcb/data DATE=`date` echo "This is the standard output for task $TASK on $DATE" /users/nrcb/bin/mycode.exe input.$TASK output.$TASKThis would enable a user to run the code mycode.exe taking it's input from a series of input files input.1,input.3,...,input.99 and sending the output of the run to output files output.1,...,output.99.
Another feature of SGE is the ability to request a variable resource. For instance you can give a process range when submitting a parallel job - e.g
qsub -pe score 5-9 my_pe_job.shThis would run a parallel job on maximum avaliable cpus in the range 4-8.
The scalar host queus are comp000.q,...comp084.q . These will all accept scalar batch and interactive jobs.
An SGE scalar batch job is very similar to a PBS one. SGE has similar commands to PBS - e.g qsub, qstat, qdel etc. Options to qsub may be embedded into the job script using #$. For instance:
#!/bin/sh # This is a test #$ -cwd pwd hostname date
The -cwd option changes to the current working directory before running the job. Unlike PBS if you don't do this then all standard output and error files are sent to a user's home directory by default. Alternatively you can submit a job using -cwd on the command line instead of embedding it :
qsub -cwd myjob.sh
Another difference between PBS and SGE is that SGE standard error and output files appear in the default location immediately and are not stored in a spool file while a job is running.
All compute nodes are set up to run both scalar and parallel jobs.