Policies and Further Resources

Policies

Legion Scheduler

• Tries to give each user an equal share of the machine at any given moment
• Tries to fill gaps with small, short jobs

“Production”

Anything that uses:

• a lot of CPU time
• a lot of RAM
• a lot of disk access

Production work should be run as a job.

What Can Run

We can provide (stable) application centrally, and compile up software to put in the /shared/ucl/apps space.

You’re free to run almost anything that you can build on Legion, though.

Some departments also provide applications, these can be viewed in the bundles section of module avail

We reserve the right to ban the use of applications that prevent or harm other users’ use of the cluster.

Limits

Time	Cores	Queue Type
≤ 15 mins	≤1 node	Rapid Test Queue
≤ 1 day	≤ 512 cores	Large Parallel Queue
≤ 2 days	≤ 256 cores	Smaller Parallel Queue
≤ 3 days	1 core	Serial Queue

(Actually more complex than this, check the website.)

Extraordinary Resource Requests

• Complete the Additional Resource Request form: https://wiki.rc.ucl.ac.uk/wiki/Additional_Resource_Requests
• Send it to your supervisor/PI to support
• Send it to us: rc-support@ucl.ac.uk
• Wait for approval by the CRAG

Data Policies

Access

• Legion is not a long-term data repository
• Do not store the only copy of your data on Legion

Security

Legion is not suitable for Highly Restricted data and above.

Level	Examples
Secret:	Identifiable patient information
…	Personal financial details
…	Confidential investigations
Highly Restricted:	Student profiles
…	Unpublished commercially sensitive material
Restricted:	UCL main web page
…	Unpublished research data
Normal:	Email about fridge-cleaning meeting

(See: UCL’s data security policy)

Responsibility for the accuracy of the results of software installed or available on Legion is the sole responsibility of researchers.

So:

• Test your software
• Check your results

Also:

• ssh is the only recommended method to connect to/from Legion
• UCL is not responsible for security of non-UCL machines
• Ensure your machines are reasonably secure

Quotas

• Home directories have a 50 GB quota
• Scratch has a 200 GB quota
• If you need more, we can make small increases (up to double)
  • For more apply to the CRAG

Support Queries

We are here to help, but we also need your assistance to be able to support you effectively.

A Good Ticket

Tell us:

• What you’re trying to do (technical)
• Exact error output
• Job IDs, scripts, and relevant file paths
• Whether we can look at your files

Keeping Tickets Sane

Subject: Re: Error When Compiling My_App v0.45 (Ref:IN:01287844)

Keeping one ticket ID per problem helps us immensely.

Other Compute Resources

UCL Funded:

• Departmental clusters
  • talk to your local IT manager

Other:

• ARCHER
• DIRAC collection
• PRACE
• US National Labs
• EGI
• (Cloud Providers)