Home
> Research
Support Group > FAQ
Research
Support Group FAQ
This is the FAQ for the research support group at the University of
Alberta. This information concerns facilities operated by the Research
Support Group of Academic Information and Communication Technologies of the University of
Alberta.
******** The Questions ********
AICT Numerical
Computing
Q: How do I gain access to
the numerical/statistical machines and the cluster?
3D Printer
Q: I'm not affiliated with
an educational/research institution in Canada, will you print my job
for me?
SGIs
Q: I can no longer log into
my account on nexus. Can you fix the problem for me?
Q: I don't have enough space
in my account to do work, can I get more disk space?
Q: Can I use a smaller
number of processors than I asked for if my program needs a lot of
memory?
Q: On arcturus, large
(>~200cpus) mpi jobs will terminate with the following error:
MPI: fork_slaves/pipe (out): Too many open files
PBS/Maui
Q: Why doesn't my PBS script
run?
Q: What are some useful
PBS/Maui commands for checking and managing my jobs?
Software
Q: I would like to access a
version of Fluent. How can I gain access to this software?
******** The Answers ********
AICT Numerical
Computing
Q: How do I gain access to
the numerical/statistical machines and the cluster?
A:
The numerical and statistical servers are available to all faculty, staff and students at the University of Alberta who can demonstrate a need for numerical computing resources.
To obtain access, have the APO or an authorized person in your department send a message to Nada Walter
(nada.walter@ualberta.ca, 301 General Services Building, or 492-0400)
requesting the access.
It takes one or two days for the account to be activated on
the servers.
Please feel free to
contact Research.Support@ualberta.ca with any further questions.
3D Printer
Q: I'm not affiliated with
an educational/research institution in Canada, will you print my job
for me?
A: Unfortunately, the
mandate of our 3D printing service is to support our University and
other universities within Canada. As such, we would not be able to
print your 3D model. There are some other rapid prototyping service
bureaus you might consider:
My apologies for having to deny your request.
SGIs
Q: I can no longer log into
my account on nexus. Can you fix the problem for me?
A: All users have a 5MB
limit on their home directories. For this reason, you should work from
your scratch directory /scratch/your_user_name. The scratch file system
does not have quotas.
Q: I don't have enough space
in my account to do work, can I get more disk space?
A: You should not keep files
in your home directory. The home directory is meant for login purposes
only and has a quota of 5Mbytes. Please do all your work in the
directory /scratch/your_user_name which should have been set up when
your account was created. The scratch file system does not have quotas.
Q: Can I use a smaller
number of processors than I asked for if my program needs a lot of
memory?
A: Yes, you can use less
processors than you asked for if you have a large memory requirement.
In fact, you should ask for enough processors to correspond to your
memory usage. The following shows the amount of memory per processor on
each of our machines:
-
arcturus:
1GB/cpu
-
nexus:
1GB/cpu
-
aurora:
259 MB/cpu
-
borealis:
256 MB/cpu
-
australis:
512 MB/cpu
-
helios:
512 MB/cpu
Q: On arcturus, large
(>~200cpus) mpi jobs will terminate with the following error:
MPI:
fork_slaves/pipe (out): Too many open files
Can you fix this for me?
A: This can be resolved by
issuing the command
limit
descriptors unlimited
before the 'mpirun' command.
PBS/Maui
Q: Why doesn't my PBS script
run?
A: A common reason for a PBS
script not running is due to the fact that home directories are not
common among the U of A machines and consequently, the login scripts
are not the same. The user must set any required environmental
variables in the PBS script and should refer to all applications using
the full path.
Q: What are some useful
PBS/Maui commands for checking and managing my jobs?
A: For some details about
PBS and Maui you can check the man pages on the host system:
Unfortunately maui documentation is currently quite poor and man pages
do not exist yet. Some useful commands are:
PBS:
'qstat' - show status of all pbs batch jobs
'qstat
-r' - show status of running pbs batch jobs
'qdel'
- delete pbs batch job
Maui:
'showres' - show reservation (when jobs are scheduled to run)
To find out when a particular job will run do 'qstat -a queuename' to
find your job number in the queue. Then use 'showres' to see when the
job is scheduled to run. For example:
fujinaga@nexus:49%
qstat -a arcturus
nexus.nic.ualberta.ca:
Req'd Req'd
Elap
Job
ID
Username Queue
Jobname
SessID NDS TSK Memory Time
S Time
---------------
-------- -------- ---------- ------ --- --- ------ ----- - -----
3941.nexus.nic.
caigenl arcturus
random_33 897014
-- 64
-- 23:30 R 01:00
3950.nexus.nic.
mruaini arcturus
np256
-- -- 256
240gb 23:00 Q
--
3975.nexus.nic.
jonathan arcturus pn.pbs
-- -- 256
250gb 23:30 Q
--
4065.nexus.nic.
caigenl arcturus
random_35 901658
-- 64
-- 23:30 R 01:00
4070.nexus.nic.
fujinaga arcturus np16
-- -- 256
-- 01:00 Q
--
fujinaga@nexus:50%
showres 4070
Reservations
ReservationID
Type S
Start
End Duration
N/P
StartTime
4070
Job I 2:20:56:15
2:21:56:15
1:00:00 1/256
Fri Mar 26 07:05:48
1
reservation located |
This tells me that job 4070 will run on Fri Mar 26 07:05:48.
Software
Q: I would like to access a
version of Fluent. How can I gain access to this software?
A: Please contact Bob Barton
@ 492-5160. He takes care of licensing this software.
Revised: June 29, 2004
|
