LSU HPC Usage Policy
▶ Table of Contents
- Individual Account Management
- Fair Use
- Reporting Suspicious Activity
- Data Confidentiality
- Software Development
- Non-Academic User Requirements
- Software Licenses
- Final Reports
- Additional Requirements
The HPC@LSU computing facilities, encompassing its hardware, software, network connections, and data, are a vital but limited resource. Therefore HPC@LSU is obligated to protect its facilities and ensure they are used properly. Allocations are used to assure equitable consumption of system resources, while personal access to the systems is controlled via user accounts. You, personally, are constrained by legal and other obligations to protect resources and the intellectual property of others on the systems.
Given the extensive nature of these resources, responsibilities are attached to the right of access. Responsible user conduct is required to assure fair access by all researchers. Failure to use these resources properly may result in various penalties, including, but not limited to, loss of access, administrative, academic, civil and/or criminal action.Back to Top
2.1. Individual Account Management
You have the responsibility to protect your account from unauthorized access, and for the proper expenditure of allocated resources. Tools are provided to help you manage your resources, but you are responsible for using these tools properly.
2.1.1. Valid Contact Email
Every account has a contact email address associated with it. Email is used as the primary communication channel between LSU@HPC and the user. The user is responsible for keeping this address up to date. In the event that an address is discovered to be invalid, the associated user account will be locked.
2.1.2. No Account Sharing
Your account is for your use only. It is not to be shared with others; neither students nor other collaborators. Others who need access must request their own account. User authentication certificates, if they are used, are considered personal accounts and not to be shared.
2.1.3. Protecting Passwords
Passwords and certificates are the keys to account access. You are responsible for their protection and proper use. Protective behavior includes
- never sharing passwords
- never writing passwords down where they can be easily found
- never using applications which expose passwords on the network (e.g. telnet).
See Guidelines, below, for more information.
The private key portion of an authentication certificate is the equivalent of a password. If you use certificates, you are responsible for ensuring that file and directory permissions prevent others from reading or copying any private keys.Back to Top
2.2. Fair Use
Access to a system does not grant you blanket authorization for any and all activity. You must recognize that reasonable use may vary from machine to machine within a system, depending on the function of the machine. Machines in a cluster serve one of two basic functions.
2.2.1. Computational Nodes
These are the nodes which perform the intended heavy computational work of a cluster. They are accessed via the job scheduler (e.g. LoadLevel or PBS) through the submission of job control scripts. Computational tasks are never to be run on the cluster head nodes, as this has the potential of impairing operation of the entire system.
2.2.2. Head Nodes
Head nodes are used for the interactive work required to prepare a computational task. Appropriate work on the head nodes includes: light editing, compiling, post analysis previewing, and job script creation. Extensive post processing should be done on the compute nodes. Any processing on the head nodes which adversely impacts system operation is subject to preemptory termination. Repeated abuse may result in the locking of user accounts or other administrative action as deemed appropriate.
2.2.3. Authorized Use
Authorized use of the system is defined by the purpose outlined in the research proposal on which the usage allocation is based. Any resulting use is limited to activities reasonably required to accomplish that purpose.
2.2.4. Unacceptable Behaviors
The following activities are explicitly deemed unacceptable and are subject to the penalties outlined below:
- using, or attempting to use, computing resources without a valid allocation and user account
- usage for purposes other than those stated in the allocation proposal.
- tampering with or obstructing the operation of the facilities.
- reading, changing, distributing, or copying others' data or software without their explicit permission.
- using HPC@LSU resources to attempt to gain unauthorized access to other (non-LSU) sites.
- activities in violation of local or federal law
2.3. Reporting Suspicious Activity
You are responsible for reporting, as soon as possible, any suspicious activity you notice on your account, and exposure or compromise of passwords, passphrases, or certificates. See Section 5 for reporting procedures.Back to Top
2.4. Data Confidentiality
You are responsible to ensure the confidentiality of any data you use on HPC@LSU resources that is restricted from general public access. Technologies are provided to preserve the confidentiality of data, but it is your responsibility to use that technology appropriately. Such data may include:
- Intellectual property, such as report drafts or research in progress,
- Proprietary data, such as data owned by a specific company, or licensed applications.
- Regulated data, such as medical, personal identifying information, or student records.
It is your responsibility to be aware of any requirements on a particular data set.Back to Top
Papers, publications, and web pages of any material, whether copyrighted or not, based on or developed under LSU-supported projects must acknowledge this support by including the following statement:
- This material is based upon work supported by HPC@LSU computing resources.
2.6. Software Development
Software developed with allocations approved by HPC@LSU is subject to the guidelines published by the LSU Office of Intellectual Property, Commercialization, and Development.Back to Top
Work performed under a peer-reviewed allocation must be published in the open literature.Back to Top
2.8. Non-Academic User Requirements
Non-academic (corporate/industrial, government, etc.) users frequently have more stringent usage requirements than those that might be provided by HPC@LSU. It is the user's responsibility to assure the resources used satisfy the requirements of their organization.Back to Top
2.9. Software Licenses
All software used on HPC@LSU systems must be appropriately acquired and used according to the specified licensing. Possession or use of illegally copied software is prohibited. Likewise users shall not copy copyrighted software or materials, except as permitted by the owner or the copyright. Some installed software may require special authorization in order to be used. Users must abide by any licensing requirements and protect it from misuse.Back to Top
2.10. Final Reports
Requests for subsequent allocation awards will not be allowed until an end of project report has been received for all prior awards. It is recommended that renewals and continuing projects also include a copy of prior award final reports as an attachment to the submitted proposal.Back to Top
2.11. Additional Requirements
Individual sites may be subject to organizational policies with additional requirements beyond this policy. Those organizations will make those policies available. It is your responsibility to be aware of and abide by those policies.Back to Top
Failure to abide by these policies may result in a variety of penalties imposed.
3.1 Account Suspension/Revocation
Accounts may be temporarily suspended or permanently revoked if compromised or abused. Your account may be suspended without advance notice if there is suspicion of account compromise, system compromise, or malicious or illegal activity.Back to Top
3.2. Loss of Allocation
Unauthorized behavior can result in loss of your current allocation, and may lead to the inability to obtain future allocations.Back to Top
3.3. Administrative Action
Unauthorized activity may be reported to your PI, your advisor, or LSU authorities for administrative review and action.Back to Top
3.4. Civil Penalties
Civil remedies may be pursued to recoup costs incurred from unauthorized use of resources or incident response due to compromise or malicious activity.Back to Top
3.5. Criminal Penalties
Activities in violation of university, federal, state, or local law may be reported to the appropriate authorities for investigation and prosecution.Back to Top
4.1. Support/Diagnostic Access
HPC@LSU site personnel may review files for the purposes of aiding an individual or providing diagnostic investigation for HPC@LSU systems. User activity may be monitored as allowed under policy and law for the protection of data and resources. Any or all files on HPC@LSU systems may be intercepted, monitored, recorded, copied, audited, inspected, and disclosed to authorized site or law enforcement personnel, as well as authorized officials of other agencies, both foreign and domestic. By using HPC@LSU systems, users acknowledge and consent to this activity at the discretion of authorized site personnel.Back to Top
4.2. Access Notification
Access to user data and communications will not normally be performed without explicit authorization and/or advance notice unless exigent circumstances exist. Post-incident notification will be provided in such cases.Back to Top
The following are suggestions for helping maintain the security of your account.Back to Top
5.1. Password Management
- Do not write down your password where it can be easily found and/or associated with your account.
- Do not tell anyone your password, not even HPC@LSU support staff. Support staff will never need your password, will never ask for it, and will never send a password in e-mail, set them to a requested string, or perform any other activity which could reveal a password.
- If someone insists they need your password to do something, report it to the HPC@LSU helpdesk: email@example.com.
- Do not store your password(s) in unencrypted files or even in encrypted files if possible.
- Pick passwords that are difficult to guess. Birthdays, family names, and single dictionary words are examples of easily guessed passwords.
- Change your password periodically, even if you have no reason to believe that anyone else has it.
5.2. Password Exposure
If you think your password may have been compromised or exposed, but have no reason to believe that your account has been used, change your password immediately.Back to Top
5.3. Account Compromise or Suspicious Activity
If you believe your account has been compromised or find signs of suspicious activity, take the following actions:
- notify the HPC@LSU helpdesk immediately (firstname.lastname@example.org)
- do not modify files found in your account
- do not execute unknown programs you might find
- if possible, do not use your account until the issue is resolved
Some indications of account compromise include:
- files in your home directory or project areas which you did not create
- alteration or deletion of your files not done by you
- discrepancies between your allocation balance and what you think you have used
The central point of contact for any problems and concerns with regards to this policy is the HPC@LSU help desk which can be reached at email@example.com. Other modes of contact are listed on the HPC@LSU web site contact us page.Back to Top
Last revised: 11 December 2009
LSU HPC Allocations Policy
▶ Table of Contents
- System Allocations
- PI Qualification
- Allocation Categories and Process
- Machine Access Policy
- HPC Resources Allocation Committee Members
1. System Allocations
LSU (Louisiana State University) maintains several high performance computing (HPC) systems. The machines currently include an IBM Power7-755 constellation, and several Intel Xeon-based x86 clusters. Detailed information on the various systems can be found on the HPC web site. LSU controls access to these resources via a formal user account and resource allocation processes. All decisions in these matters are made by the LSU HPC Resource Allocation Committee (HPCRAC), which is made up of faculty representatives from different discplines across LSU.
A 2-step process is required to gain access to LSU HPC resources, be they computational time or data storage. The first step requires applying for a system user, or login, account. The second step requires associating the user account with an allocation. An allocation provides the means for assigning, tracking, and controlling resource consumption. While the process is similar for both computational time and storage space, there are separate policy documents for each. This particular document will focus on allocations for computational time.
An allocation of computational time is analogous to a bank account. It provides processor time that a user may expend as they see fit on one or more systems. When that time is consumed, no more work can be done until a new allocation is identified. Individuals who are awarded an allocation (called the principle investigator, or PI) have the ability to add users to their allocation account thus allowing multiple people to use one allocation. The PI consequently retains ultimate responsibility for who uses their allocation and how it is expended.
Computational allocations are awarded in units called service units (SU), where 1 SU corresponds to running a program for 1 wall clock hour on 1 processing core. How cores are associated with a program varies from system to system. All allocations are awarded for 1 year periods, and are considered active until they expire, even if the SU balance has gone to zero. As the policy will outline, there are limits on both the total allocation amounts, and number of active allocations a PI may hold at any given point in time.Back to Top
2. PI Qualification
For the purpose of computational allocations, only active LSU faculty members and permanent research staff (subject to HPCRAC Chair review and approval) are qualified to serve as a PI. Adjunct and Visiting professors do not qualify. Requesting an allocation involves submission of a project proposal describing the intended usage and providing justification for the resource amounts requested. Actual submission is controlled by web pages on the HPC web site, and varies in complexity with the size of the request.
Once an allocation is awarded, the PI is granted access to tools which allow tracking of SU consumption, as well as the management of additional users who may use it. Associated with each allocation is an account code which is used by the system to determine how to charge for resources consumed. The PI is ultimately responsible for all users they authorize on an allocation, but has the option of formally delegating some other user on the allocation to manage this process in their stead. It becomes the joint responsibility of the PI and the authorized users to make sure the allocation is expended properly, and for the purposes intended.
LSU welcomes members of other institutions who are collaborating with LSU researchers to use LSU resources, but they cannot be the PI requesting standard allocations (Default, Startup or Research) or granting access. They must ask a qualified PI at LSU to sponsor them for a user account and add them to an appropriate existing allocation.Back to Top
3. Allocation Categories and Process
At the present time, allocations are machine-specific awards, allowing user only on the platform they are awarded for. HPC resources are partitioned by category, and requests go through the HPCRAC (HPC Resource Allocation Committee). The HPCRAC represents several distinct approval authorities: the Vice Chancellor for Research and Economic Development (VCRED), the Center for Computation & Technology (CCT) Director, the HPCRAC Chair, and the HPCRAC as a panel. This reflects the sponsorship and many intended uses for LSU HPC resources. The resources intended for each use are collected into 5 categories as shown in Table 1.
|Allocation Category||Available Resources||Allocation Authority|
|Economic Development||10%||Vice-Chancellor for Research and Economic Development|
|Discretionary||10%||Center for Computation and Technology Director|
|Default Allocation (2,000 SU's)||5%||HPC@LSU Staff|
|Startup Allocation (2,000-50,000 SU's)||15%||HPCRAC Chair|
|Research Allocation (> 50,000 SU's)||60%||HPCRAC|
To facilitate management of proposals, they will be assigned to one of the following classes (Table 2).
|Economic||A proposal to assist commercial interests with the adoption of high performance computing as part of their business process. Awarded by the VCRED from the Economic Development resources. Economic allocations may be renewed by the VCRED.|
|Discretionary||A proposal determined to be of value, but lying outside the normal allocation process. Awarded by the CCT Director from the Discretionary resources. Discretionary allocations may be renewed by the director.|
|Default||Every user account, upon creation, receives a default allocation. This allows sufficient time for conventional processing on the systems, and developing information for potential formal proposals. These allocations are limited to 2,000 SU's. Default allocations are not renewable.|
|Startup||A proposal requesting an allocation for the purpose of exploring the value of high performance computing for a new project. A PI is allowed to have a maximum of 2 startup allocations active at any given time. Startup allocation of 2,000 to 50,000 SU's are awarded by the HPCRAC Chair.|
|Research||A request for a large amount of time for a significant research project. May be awarded by simple majority agreement of the HPCRAC. Research requests are limited to 3 million SU's, and a PI may have a total of 5 million SU's active at any given time. Research allocations may be eligible for renewal by the HPCRAC.|
All allocations have a duration of one year. Default and Startup allocations may be awarded at any time during the year, and Default allocations, in particular, are awarded on creation of a user account. Research allocations are granted at the beginning of every calendar quarter. Application deadlines for Research allocations are one month prior to the start date: January 1, April 1, July 1, and October 1. A PI may request, or be requested, to make a formal presentation to the HPCRAC in conjunction with the proposal submission. At the end of any allocation, a short summary report is required by the HPCRAC. Missing reports may delay proposal processing. Any request for an allocation renewal must include a summary report. The summary should indicate if the goals of the proposed work were accomplished, any major results, and list any publications and presentations that result.
Allocations can not be extended. They are based on estimated resources available during the award period, and those resources effectively dissipate as time passes, whether used or not. The PI is ultimately responsible for assuring allocations are used at a rate needed to support their project over the timeframe of the allocation.Back to Top
3.1. Standard Allocation Limits, Requests and Renewals
3.1.1. Default Allocations (2,000 SU's)A default allocation of 2,000 SU's is awarded by HPC staff to every new user account. The computationally-driven activities of any individual whose HPC resource needs exceed 2,000 SU's in a given year may be subject to a review by the HPCRAC Chair. If more time is required, one of the other allocation awards described below must be considered.
3.1.2. Startup Allocations (<50,000 SU's)
Who may apply:Any qualified PI may request a Startup allocation for up to 50,000 SU's. Consideration must be given to the limitation on the number of simultaneous Startup allocations a PI may have active at any one time, as specified in Table 2. The intent is to support low intensity projects, such as small analysis efforts or course work.
How to apply: An application may be submitted using the HPC web interface. Completing the web form alone is sufficient. The text provided should briefly explain the computation time on the selected HPC platform, the intended methodology, and the current state of the codes or application that will be used.
Review and Awards: Startup allocations may be made at any time throughout the year, but their start time is set to the beginning of the allocation quarter they are made in.
Renewals Upon request, startup allocations may be renewed annually; renewal applications must be accompanied by a summary report including a list of publications and presentations in which the use of LSU HPC resources has been acknowledged.Back to Top
3.1.2. Research Allocations (>50,000 SU's)
Who may apply:Any qualified PI may request a Research allocation for more than 50,000 SU's, up to the maximum defined in Table 2. Research allocations can be for their own use, or on behalf of a research or operational group in support of a well-defined compute-intensive project. Requests must take into account any limitation given in Table 2 on size and the total SU's a PI may have active at any one time.
How to apply: A request for an allocation requires that a formal proposal be submitted via the HPC web interface to the HPCRAC. In addition to the web form information, the formal proposal must be in PDF format, and should be 5 pages or less. The emphasis must be on justifying the computational resources requested. The follow outline should be followed:
- Problem Statement – Section limited to 1 page, or less, describing the desired outcomes of the project.
- Background – Section limited to 1 page, or less, describing how the resources will be used to address the problem (i.e. student access for course work, specific models, etc).
- Methodology – Section limited to 1 page, or less, describing the computational methodology that will be used. This should include the applications required.
- Research Plan – Section limited to 1 page, or less, describing the research schedule, including the anticipated expenditure of granted resources. Allocations are assumed to be uniformly consumed over their lifetime. If this will not be the case, an estimate of expenditure by quarters is required.
- Requirements Analysis - Section limited to 2 pages, or less, detailing the basis for the requested computer time. Large allocations must exhibit an understanding of application efficiency, scaling, and provide accurate estimations of the time requirements.
Please note that the maximum proposal page limit is 5, not including summary reports in the Attachments. The page limit was chosen with an eye to making it relatively easy to compose an allocation request, and to modify and reuse a successful application made to another center. Additional information may be attached as addendums, such as copies of awarded grants which will be supported by the requested resources. The PDF file is limited to a maximum of 2 MB, and will be rejected if the file is over this limit.
Review and Awards: Applications for a Research allocation will undergo competitive peer review and will be allocated quarterly by the HPCRAC. Requests will be granted – in whole or in part – based on the availability of HPC resources and based upon the description of the proposed activities and the appropriate use of technology, with priority given to funded projects. Allocation decisions made by the HPCRAC are deemed final. Unresolved appeals will be directed to the Vice Chancellor for Research & Economic Development (VCRED).
Renewals: Renewal allocations follow the same process as all other allocations. Proposal writers should be aware that both past usage history and submission of progress reports will be considered in the award determination. Applications for allocation renewals should ideally cite peer reviewed publications that acknowledge LSU HPC resources and only require an updated version of a previously successful application.Back to Top
3.2. Director's Discretionary Allocation Request (submit to CCT Director)
Each calendar year, up to 10% of the available HPC resources will be allocated at the discretion of the CCT Director and the Chief Information Officer (CIO). Allocations made from this pool will be for a period not to exceed one year. Awardees will be expected to work in conjunction with CCT or HPC@LSU technical staff to ensure that project implementations are in line with and strengthen the CCT's broad interdisciplinary mission. At the termination of a project (or annually, if an award is extended beyond one year) awardees shall provide a summary report of project activities along with a list of publications and presentations in which the use of LSU HPC resources has been acknowledged.Back to Top
3.3. Economic Development or 'On Demand' Allocation Request (submit to VCRED)
The VCRED, in consultation with the chair of the HPCRAC and the CCT Director, may grant Economic Development or On Demand access to HPC resources for high priority projects like render farm for economic development purposes, hurricane storm surge modeling, or other possible operational responsibilities that are deemed sufficiently different from standard research proposals. Each calendar year, up to 10% of the available HPC resources may be allocated by the VCRED. At the termination of a project (or annually, if an award is extended beyond one year) awardees shall provide a summary report of project activities along with a list of publications and presentations in which the use of LSU HPC resources has been acknowledged.Back to Top
3.4. Allocation Management
An allocation is considered valid so long as a positive resource balance remains, and the expiration date has not been exceeded. Once an allocation expires, or has been fully consumed, users accounts will be blocked from submitting work against the allocation. There is no mechanism for extending an allocation beyond one year, nor for adding resources once an allocation has been expended.
User accounts must be associated with a valid allocation, and if not, will be retained for a maximum of 1 year pending authorization against a renewed or different allocation. With these restrictions in mind, the PI is required to use the tools provided to monitor system usage and control authorization of project member accounts. PIs are strongly advised to carefully budget their usage appropriately throughout the year. Automatic reminder emails will be sent by the management system as an allocation nears expiration. PIs are ultimately responsible for assuring that a current and actively monitored management email address has been assigned to each allocation.
At the end of any allocation, a short summary report must be submitted to the allocation committee. Failure to submit this report may be used in the consideration of future allocations. The report may simply reference any formal publications and presentations that resulted from using HPC resources, or provide a high level overview of what was accomplished.Back to Top
3.5. Early Allocation Access
If a PI who has already been awarded a Research allocation by HPCRAC puts in a new request, and there is a good reason to start the project before the next cycle, then the HPCRAC Chair can instruct the HPC@LSU staff to award as much as 25% of the project request immediately. Justification must be provided in the renewal proposal. The HPCRAC committee would be made aware of this action and its reasons by the HPCRAC Chair using the "LSU HPC Allocations" email list.Back to Top
4. Machine Access Policy
4.1. Job Queueing
Various workload balancing algorithms are used to determine how jobs are assigned resources on a given machine. The way a job is handled is determined by the job queue it is submitted to. Efficient use of the queuing system requires that users request runtimes consistent with estimated runtimes of their jobs. In particular, requesting more time than is necessary for a particular job can lead to inefficient and unfair queuing. Therefore, users that routinely request more time than is needed for their jobs are subject to a priority penalty that will lower the priority of their jobs. Each system sets a maximum number of jobs that a single user may have running without special permission (see below). There is no limit to the number of jobs that a particular user may have queued. Users that wish to obtain a higher priority for their jobs may use special priority queues (see below).
The available processors are currently divided into 2 architecture specific groups: IBM P7-755 systems running AIX, and Intel x86 systems running Linux. The processors in each group are further subdivided into preemptory and dedicated pools. Certain mission critical applications, such as storm surge prediction during a hurricane threat, are granted immediate access to processors in the preemptory pool. Processors in the dedicated pool are used to run all other job types. The processors are accessed through different job queues. There are 5 job queues which use different combinations of the processor pools, and allow for different job characteristics.
- Preempt Queue: The preempt queue controls access to the preemptory pool. Authorized applications submitted to this queue will cause the termination of all other user applications running on preemptory nodes.
- Checkpt Queue: The checkpt queue controls access to nodes in both the dedicated and preemptory pool. Jobs running in this queue may be subject to termination by the preempt queue, thus are implicitly assumed to support restarts based on periodically saved information. No refunds of lost SU's are offered if jobs in the checkpt queue are terminated by preemption. The user running jobs without restart capability assume this risk. However, the benefits from using this queue include access to larger numbers of nodes, and/or faster throughput, depending on how busy the queue is.
- Workq: The workq queue controls access to nodes in the dedicated pool. Jobs in the work queue will run until they terminate as planned, their requested run time has expired, or they stop due to an abnormal system failure. Jobs which are terminated due to system errors beyond the user's control may be subject to refund of expended SU's. Poor planning is not considered grounds for a refund.
- Interactive Queue: The interactive queue gives real-time access to jobs for on-line analysis or debugging, but only allows very short run times. It supports development work, but not production.
- Priority Queue: The priority queue controls nodes in the dedicated pool, but allows applications to be given higher priority with prior approval. Approval may be granted during training sessions, for demonstration purposes, or other special needs. The SU's charged will be adjusted by a factor of 1.3, and no more than 20% of an allocation may be expended in the queue. Requests for priority access should be directed to firstname.lastname@example.org. This queue does not impact other running user jobs, but will delay the start of lower priority jobs already in the queue.
Note: The named queues do not necessarily exist on all machines, and the maximum time allowed in the queues will vary from machine to machine.Back to Top
Currently disk space usage is controlled via user quotas rather than on a per-project basis. Storage may become an allocated resource in the future. At such time, a request for storage space will be required in the allocation request. At the current time, an estimate of required space is requested.Back to Top
4.3. Special Requests
A request for special access to LSU HPC machines (such as usage of all nodes on a machine or exceptionally long runs) must be explicitly stated in the proposal for HPC resources. Appeals to the decision of the HPCRAC may be made to the VCRED.Back to Top
5. HPC Resources Allocation Committee Members
The proposed HPCRAC members are shown in Table 3. The CCT Director, in consultation with the VERED, appoints the Chair of HPCRAC. The HPCRAC is chartered approval authority allocating HPC resources, and charged with the task of adopting the HPC Resources Allocations Policy and reporting its activities and recommendations to VCRED.
|Honggao Liu (Chair)||CCTemail@example.com|
|Jim Q. Chen||Civil & Environmental Engineeringfirstname.lastname@example.org|
|Shawn W. Walker||Mathematicsemail@example.com|
|Krishnaswamy Nandakumar||Chemical Engineeringfirstname.lastname@example.org|
|Jeremy Brown||Biological Sciencesemail@example.com|
Summary report: This report should be a maximum of 5 pages and should include the following information:
- Principal user information [PI] (name, status, department, phone, email, institution [if different from LSU]
- Summarize the nature of the LSU-sponsored research in a non-technical fashion, suitable for public consumption. (Approximately one page; no more than two pages)
- Describe any potential applications of the research to industry or government.
- Describe any use of this allocation to encourage education in computational science, and particularly the level of student involvement and any HPC elements incorporated into formal courses.
Definition of Service Unit (SU): Currently, one SU corresponds to one hour of wall-clock time on one processing core. A single machine will have multiple nodes (individual servers) available, and multiple cores within each node. This allows many cores to be used for a single parallel processing job, but can lead to not-so-obvious charges. For example, running for 1 hour using 8 cores on an 8-core node consumes 8 SU's. On the other hand, running for 1 hour on 1 core of the same 8 core node, which allows the single core to access all of the node memory, also consumes 8 SU's. In simple terms, the number of cores that are reserved for a job, and hence are unavailable to others, is the number used to calculate SU usage.
HPC resources at LSU will be allocated/charged according to the number of “service units (SU's)” required/used, where:
# SU's = m * #Nodes * Wall_Time,
m = number of processing cores per Node;
Wall_Time = Total Wall Clock Hours.
For example, if a machine has 4 processing cores per Node (m = 4), a program that ran for 24 hours on 32 nodes required 4*32*24 = 3072 SU's.Back to Top
Last revised: 5 September 2014
LSU HPC Storage Policy
▶ Table of Contents
See also: ITS Faculty Data Storage.
1. Storage Systems
Available storage on LSU@HPC high performance computing machines is divided into four file systems (Table 1). More complete descriptions of follow below.
|/scratch||Temporary storage on each node that is available only during job execution.|
|/work||Shared storage provided to all users for job input, output, and related data files. Files are not backed up and may be subject to purge!|
|/home||Persistant storage provided to each active user account. Files are backed up to tape.|
|/project||Persistant storage provided by request for a limited time to hold large amounts of project-specific data. Files are not backed up.|
All file systems share a common characteristic. When they are too full, system performance begins to suffer and all users suffer from the effects. Similarly, placing too many individual files in a directory degrades performance. System management activities are aimed at keeping the different file systems below 80% of capacity. It is strongly recommended that users hold file counts below 1,000, and never exceed 10,000, per subdirectory. If atypical usage begins to impact performance, individual users may be contacted and asked to help resolve the issue. When performance or capacity issues become significant, system management may intervene by requiring users to offload files, stop jobs, or take other actions to ensure the stability and continued operation of the system.
Management makes every effort to avoid data loss. In the event of a failure, every effort will be made to recover data. However, the volume of data housed makes it impractical to provide system-wide data backup. Users are expected to safeguard their own data by making sure that all important code, scripts, documents and data are transferred to another location in a timely manner. The use of inexpensive, high capacity external hard drives attached to a local workstation is highly recommended for individual user backup.Back to Top
2. File System Details
/scratch space is provided on all system nodes, but is only available to users during the course of a job. The files are subject to deletion once a job ends. The size of this file system will vary from system to system, and possibly across nodes within a system. This is the preferred place to put any intermediate files required while a job is executing. Users should not have any expectation that files will exist after a job terminates, and are expected to move the data from /scratch to their /work or /home directory as part of the clean up process in their job script.Back to Top
/work is the primary file storage area to utilize when running jobs. /work is a common file system that all system nodes have access to. It is the recommended location for input files, checkpoint files, other job output, as well as related data files. Files on /work are not backed up, making the safekeeping of data the responsibility of the user.
User may consume as much space as needed to run jobs, but must be aware that since the /work file systems are fully shared, they are subject to purge if they become overfull. If capacity approaches 80%, an automatic purge process is started by management. This process targets files with the oldest age and size, removing them in turn until the capacity drops to an acceptable level. The purge process will normal occur once per month, as necessary. In short, use the space required, but clean up afterwards. See the description of /project space below for longer term storage options.Back to Top
All user home directories are located in the /home file system. /home is intended for the user to store source code, executables, and scripts. /home may be considered persistent storage. The data here should remain as long as the user has a valid account on the system. /home will always have a storage quota, and is clearly a hard limit. While /home is not subject to management activities controlling capacity and performance, it should not be considered permanent storage, as system failure could result in the loss of information. Users should arrange for backing up their own data, even though /home is periodically backed up to tape.Back to Top
The /project file system may be available on some systems, and provides storage space for a specific project. /project space is allocated and must be requested. It is made available for 6 months at a time. Shortly before an allocation expires the user will be notified of the upcoming expiration. Users may request to have the allocation extended. Renewal requests should be submitted at least 1 month prior to expiration to allow decision and planning time. Users should have no expectation that data will persist, and may be erased any time after 1 month from a project’s expiration. Thus the user is encouraged to employ alternate safe keeping and protection solutions of their own.Back to Top
2.5 System Specific Information
|Purge File Limit
|/project||200 (LPFS)||By Request|
|/project||840 (LPFS)||By Request|
3. Job Use
On all systems, jobs must be run from the /work file systems, and not from the /home or /project file systems. The individual nodes assigned to a job will have access to their local /scratch space. Files should be copied from /home or /project space to /work before a job is executed, and back when a job terminates, to avoid excessive I/O during execution that degrades system performance. Files can not be copied into /scratch space until a job begins.Back to Top
4. /project Allocation Requests
Limitations: Space is allocated on the /project file systems by request for periods of upto 6 months at a time. Renewal requests are allowed but, in the interest of fairness, are subject to availability and competing request.
How to Apply: A storage allocation may be requested by completing a web form. The provided information should fully justify the need for the storage, and indicate how the data will be handled in the event the allocation can not be renewed. A user group can be set up for sharing access to the space if the requestor includes a list of user names.
Allocation Class: Allocations are divided into 3 classes, each with a separate approval authority (Table 3). All storage allocation requests are limited by the available space, and justifications must be commensurate with the amount of space required.
|Small||Up to 100GB||HPC@LSU Staff|
|Medium||Between 100GB and 1TB||HPC@LSU Operations Manager|
|Large||Over 1TB||HPC@LSU Director|
 Global Parallel File System
 Lustre Parallel File System
 Network File System
 Physically shares /work
Last revised: 10 Dec 2014
Users are asked to acknowledge their use of LSU HPC resources in resulting publications and reports with the following statement:
Portions of this research were conducted with high performance computational resources provided by Louisiana State University (http://www.hpc.lsu.edu).