Narwhal Quick Start Guide
1. Introduction
This document provides a brief summary of information you'll need to quickly begin working on Narwhal. For more detailed information, see the Narwhal User Guide.
2. Get a Kerberos Ticket
For security purposes, you must have a current Kerberos ticket on your computer before attempting to connect to Narwhal. A Kerberos client kit must be installed on your desktop to get a Kerberos ticket. Information about installing Kerberos clients on your Windows desktop can be found on the Kerberos & Authentication page.
3. Connect to Narwhal
Narwhal can be accessed via Kerberized ssh as follows:
% ssh user@narwhal.navydsrc.hpc.mil
4. Home, Working, and Center-wide Directories
Each user has file space in the $HOME, $WORKDIR, and $CENTER directories. The $HOME, $WORKDIR, and $CENTER environment variables are predefined for you and point to the appropriate locations in the file systems. You are strongly encouraged to use these variables in your scripts.
Note: $WORKDIR is a "scratch" file system, and $CENTER is a center-wide file system accessible to all Navy DSRC production systems. Neither of these file systems is backed up. You are responsible for managing files in your $WORKDIR and $CENTER directories by backing up files to the archive system and deleting unneeded files. Currently, $WORKDIR files older than 14 days and $CENTER files older than 180 days are subject to being purged.
If it is determined as part of the normal purge cycle that files in your $WORKDIR directory must be deleted, you WILL NOT be notified prior to deletion. You are responsible to monitor your workspace to prevent data loss.
5. Transfer Files and Data to Narwhal
File transfers to DSRC systems must be performed using Kerberized versions of the following tools: scp, sftp, and mpscp. For example, the command below uses secure copy (scp) to copy a local file into a destination directory on a Narwhal login node.
% scp local_file user@narwhal.navydsrc.hpc.mil:/target_dir
For additional information on file transfers to and from Narwhal, see the File Transfers section of the Narwhal User Guide.
6. Submit Jobs to the Batch Queue
The Portable Batch System (PBS) is the workload management system for Narwhal. To submit a batch job, use the following command:
qsub [ options ] my_job_script
where my_job_script is the name of the file containing your batch script. For more information on using PBS or job scripts, see the Narwhal User Guide, the Narwhal PBS Guide, or the sample script examples in the $SAMPLES_HOME directory on Narwhal.
7. Batch Queues
The following table describes the PBS queues available on Narwhal:
Priority | Queue Name | Max Wall Clock Time | Max Cores Per Job | Description |
---|---|---|---|---|
Highest | urgent | 24 Hours | 16,384 | Jobs belonging to DoD HPCMP Urgent Projects |
frontier | 168 Hours | 65,536 | Jobs belonging to DoD HPCMP Frontier Projects | |
high | 168 Hours | 32,768 | Jobs belonging to DoD HPCMP High Priority Projects | |
debug | 30 Minutes | 8,192 | Time/resource-limited for user testing and debug purposes | |
HIE | 24 Hours | 3,072 | Rapid response for interactive work. For more information see the HPC Interactive Environment (HIE) User Guide. | |
viz | 24 Hours | 128 | Visualization jobs | |
standard | 168 Hours | 32,768 | Standard jobs | |
mla | 24 Hours | 128 | Machine Learning Accelerated jobs that require a GPU node; PBS assigns the next available smla (1-GPU) or dmla (2-GPU) node. | |
smla | 24 Hours | 128 | Machine Learning Accelerated jobs that require an smla (Single-GPU MLA) node. | |
dmla | 24 Hours | 128 | Machine Learning Accelerated jobs that require a dmla (Dual-GPU MLA) node. | |
serial | 168 Hours | 1 | Serial jobs | |
bigmem | 96 Hours | 1,280 | Large-memory jobs | |
transfer | 48 Hours | 1 | Data transfer for user jobs. See the Navy DSRC Archive Guide, section 5.2. | |
Lowest | background | 4 Hours | 1,024 | User jobs that are not charged against the project allocation |
8. Monitoring Your Job
You can monitor your batch jobs on Narwhal using the qpeek, qview, or qstat commands.
The qstat command lists all jobs in the queue. The -u username option shows only jobs owned by the given user, as follows:
% qstat -u user1 Req'd Req'd Elap Job ID Username Queue Jobname SessID NDS TSK Memory Time S Time -------- -------- -------- ------- ------ --- --- ------ ----- - ----- 815.narwhal-pbs1 user1 debug mytest 1766 1 128 -- 00:30 R 00:12 824.narwhal-pbs1 user1 frontier inspect -- 8 1024 -- 06:00 Q -- 825.narwhal-pbs1 user1 standard 45dh8 2584 10 128 -- 02:00 R 14:22
Notice that the output contains the JobID for each job. This ID can be used with the qpeek, qview, qstat, and qdel commands.
To delete a job, use the command qdel jobID.
To view a partially completed output file, use the qpeek jobID command.
9. Archiving Your Work
When your job is finished, you should archive any important data to prevent automatic deletion by the purge scripts.
Copy one or more files to the archive system.
archive put [-C path ] [-D] [-s] file1 [file2 ...]
Copy one or more files from the archive system.
archive get [-C path ] [-s] file1 [file2 ...]
For more information on archiving your files, see the Navy DSRC Archive Guide.
10. Modules
Software modules are a very convenient way to set needed environment variables and include necessary directories in your path so commands for particular applications can be found. Narwhal uses modules to initialize your environment with COTS application software, system commands and libraries, compiler suites, environment variables, and PBS batch system commands.
Several modules are loaded automatically as soon as you log in. To view the currently loaded modules, use module list. To see the entire list of available modules, use module avail. You can modify the configuration of your environment by loading and unloading modules. For complete information on how to do this, see the Navy DSRC Modules Guide.
11. Available Software
A list of software on Narwhal is available on the Software page.
12. Advance Reservation Service (ARS)
A subset of Narwhal's nodes has been set aside for use as part of the ARS. The ARS allows users to reserve a user-designated number of nodes for a specified number of hours starting at a specific date/time. This service enables users to execute interactive or other time-critical jobs within the batch system environment. The ARS is accessible at https://reservation.hpc.mil. Authenticated access is required. For more information on ARS, see the ARS User Guide.