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Admin FAQ

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This FAQ discusses how HPCx is run, and how to make use of SAFE, the software suite which we use to administer the service. Technical issues are covered by the general FAQ.

Contents

General information

For general users

For PIs and project managers

General information

Q. Who runs HPCx?
A. HPCx is provided by a consortium which includes the University of Edinburgh, the Council for the Central Laboratory for the Research Councils (CCLRC) and IBM. The consortium operates as a company, UoE HPCx Ltd, which is owned by Edinburgh University. The two departments principally working on HPCx are EPCC at the University of Edinburgh, and the Computational Science and Engineering Department at CCLRC Daresbury Laboratory.

HPCx operates within a contract between the consortium and the Engineering and Physical Sciences Research Council (EPSRC). EPSRC acts as an agent for the UK Research Councils, who fund the entire service. The disposition of the time and other resources of the service is therefore in the hands of EPSRC. A part of the resources is reserved for commercial and industrial use, and this is available to be bought. The rest is allocated to research projects which are funded by the Research Councils.

Q. How can I start a project on HPCx?
A. If you are a researcher who is eligible for support by the Research Councils, you must apply to EPSRC for access. Information about applying for access to HPCx and to the UK's other national HPC service at HECToR, can be found on the EPSRC website, where you can also find the application form. There is also a copy of the form on this site, both in Word and PDF format. Access is given in two classes: Class 1, for projects which are ready to make extensive use of the service, and Class 2, for projects who wish to try out their applications before making a Class 1 application. Please note Class 2 access has now been re-opened on HPCx.

If you are a possible commercial or industrial user of the service, and are considering purchasing time, please in the first instance contact the Helpdesk.

Q. How are projects organised?
A. We set up a project on the service when we are directed by EPSRC to do so. EPSRC tell us who the Principal Investigator (PI) is, and what resources the project should have. The PI is in charge of that project. They decide who can get access to the service as part of the project, and how the resources are used.

Administration of the project is mostly done through SAFE software suite. Any user of the service can use SAFE, but PIs have special privileges to enable them to administer their projects. Some PIs prefer not to do the day-to-day administration themselves; instead, they can designate project managers, who will have most of the PI's privileges.

Some projects, especially large ones, prefer to work as a number of sub-projects. In SAFE terminology, these are called project groups. The PI or project manager can create project groups, decide their memberships and allocate resources for their exclusive use. A user can belong to more than one project group.

Q. What is SAFE?
A. SAFE stands for Service Administration from EPCC. It is a large web-based application, provided by EPCC for HPCx. The same software is used by the HECToR service.

Every user of HPCx has an account on SAFE. You can use your SAFE account to check your use of time and space now and in the past, to apply to join other projects and create service machine accounts, to change passwords, to keep your personal details up to date, to request higher priority for a job, to check the progress of the helpdesk queries you have submitted, to use the token system to express your feelings about HPCx, and so on. PIs and project managers can do many other things.

The HPCx team also uses SAFE to administer the system and to generate reports. The helpdesk software is also part of SAFE.

The SAFE database is administered according to the HPCX Personal Data and Privacy Policy. Although the same software is used to administer HPCx, HECToR and EPCC's own services, the databases are entirely separate and held on different servers.

Q. How are resources organised?
A. EPSRC only allocates computer time to projects. This time is measured is allocation units (AUs). The AU measures time only, not disk space or anything else. It is not the same sort of thing as a CSAR generic token and cannot be traded for other resources. This page discusses how the AU is used to measure time, and how the nominal cost of a project is calculated.

We allocate disk space and tape store space. We take into account the space requested in the project's grant application, the amount of time they have asked for and how much space we have available. More space is allocated if needed, and if it's available. Disk space is allocated in two classes: homespace, which is backed up, and workspace, which is not.

Each project is assigned a code, such as t01. Within the project there may be a number of project groups. In fact, there are always at least two:

The other project groups have codes of the form t01-abcd, and their memberships are decided by the PI or project manager. PIs and project managers can move resources between these project groups.

Each project group has a budget with the same name as the project group. Budgets are used to store time, measured in AUs. When you run a job, you must specify which budget you are using. The time you use is then taken from that budget.

Project groups may also have their own disk and tape quotas. This isn't compulsory, however, and many projects prefer their project groups to share the disk space without quotas. (Project group quotas have to be implemented using Unix group quotas, which are barely adequate for the task.)

Q. How are accounts organised?
A. There are two kinds of account on HPCx: accounts on SAFE, and accounts on the service machine itself. Most users will have one of each, although PIs may choose to have only an account on the admin website.

If you belong to more than one project, you may like to have a separate account on the service machine for each of them. Alternatively, you can use the same account. If you do this, you will log in to your directory in the homespace of the first project you joined, and you will have to move to the project you wish to work in.

No matter how many service machine accounts you have, you should have only one SAFE account.


For general users

Q. How can I get an account on HPCx?
A. First thing: you must belong to a project which already exists on HPCx. You will need to know:

The Principal Investigator (PI) of your project, or its project manager, will supply these to you.

It's explained here that you will need two accounts: one on SAFE, and one on the service machine itself. However, you can register for both of them at once. Once you have your project code and the project password, this is what to do.

Next you will be asked to accept the Terms and Conditions of Access, by clicking the appropriate button. When you do this, you will be sent an acknowledgment by email, which will include your SAFE password - you should change this as soon as possible (see below).

Now you have to wait for your PI or project manager to accept your request to register. When this has happened, the systems team are prompted to create your account on the service machine. Once this has been done, you will be sent an email. You can then pick up your password for the service machine from your SAFE account (see below).

Q. How can I login to SAFE?
A. Go to https://www.hpcx.ac.uk/. Then:

Q. How can I pick up my password for the service machine?
A. Wait till you receive the email with your details. Then:

This password is generated randomly by the software. It will be hard to remember and will probably include a selection of "l", "1", "O" and "0" characters. For this reason it's best to copy-and-paste it across when you log in to the service machine. Once you have logged in, you can change your password to something more memorable; this is discussed in the User Guide. Note that when you change your password on the service machine in this way, this is not reflected on the website.

Q. I've forgotten the password to my account on the service machine. How can I change it using SAFE?
A. Login to SAFE. Then:

Now the systems team will change your password. When this has been done, you will be informed by email; this means that you can come back to SAFE and pick up your new password.

Q. How can I change my SAFE password?
A. Login to SAFE. Then:

Q. I've forgotten my SAFE password. What can I do?
A. Go to https://www.hpcx.ac.uk/. Then:

SAFE will only mail to email addresses it already knows. But email is not a secure medium, so if you change your password this way, you should immediately change it again from inside the website.

Of course, anyone could go to SAFE, type your email address and request a new password by clicking "Email". If that happens you will receive an email message out of the blue saying that your password has been changed. In this case you should certainly change your password again.

Q. I'm already a user of HPCx in one project. Now I need to join another project as well. How can I do this?
A. There are two ways to do this: open a new account on the service machine to use for the new project; or, use your existing account for both projects.

To open a new account for the new project:

The PI or project manager of the new project will be asked to approve your request to join their project. After that, the systems team will be asked to create the account, and when this has been done, you will be sent an email. You can then come back to SAFE and pick up the password of your new account.

To use your old account for the new project:

The PI or project manager of the new project will be asked whether they wish to accept you. After that, the systems team will be asked to make the changes needed to join you to the new project, and when this has been done, you will be sent an email.

Note that if you use this second technique, you will now have a directory in each of the projects. When you log in, your current directory will be in your original project, so if you want to work on the second project, you must cd to your directory there. If you create a file or a directory, it will belong to the project of the directory it's created in, and will be charged against that project's quota. It's your responsibility to make sure that files are charged to the right projects.

[For those who are interested: each project has its own Unix group—in fact, more than one, if it's using project group quotas. Every directory in the file system has the set-GID bit (also called the "sticky bit") set, so that group ownership is inherited. Clearly it wouldn't be hard to subvert this system, but that would be against the Terms and Conditions.]

Q. How can I change personal details about me held by SAFE?
A. Login to SAFE. Then:

Don't forget the last step, or nothing will happen. Note that your postal address does not automatically include the name of your department and institution; if you want these in your postal address, you must type them again.

Q. How can I change my email address as known to SAFE?
A. At present, the only way to do this is to request the change by contacting the helpdesk. We would normally only do this in response to an email request which comes from the existing email address, and we would ask for a confirmation from the same address.

Q. How can I be removed from the email mailing list?
A. Login to SAFE. Then:

Don't forget the last step, or nothing will happen.

Q. How can I request higher priority for a job?
A. You can only do this when the job has already been submitted. Use the llq command to view the details of the jobs in the queues, and note the id of the job or jobs you wish to have priority. Then:

Your request will be checked by the HPCx team. Obviously we cannot give priority to every job, so you will need to make a convincing case to justify your job jumping ahead of other people's.

Q. How can I register a Globus certificate for a service machine account?
A. Login to SAFE. Then:

Q. How can I see how much time and space are available to me?
A. Login to SAFE and move down to the panel headed "You are a member of the following project groups". Here you can see how much time is left in each project group's budget. You can also see the quotas for home, work and archive space (if the project group is using these) and how much is in use.

The budget values displayed are updated every morning, and the values shown for disk and tape use are updated four times a day. For this reason, all these values may not be completely up-to-date. If there is a lot of activity in your project, the numbers shown could be significantly different from from the current ones.

Q. How can I review the use I have made of the service, or the activity of the service as a whole?
A. Login to SAFE. Then:

Q. How can I check the active queries I have submitted to the helpdesk?
A. Login to SAFE. Then:

This will show you the queries of yours that haven't yet been resolved. Note that some of the internal correspondence about a query will not be shown. You can also use SAFE to submit a query - use "Submit a new helpdesk query".

Q. How can I register my approval — or my annoyance?
A. Login to SAFE. Then:

Changes in your token level are emailed directly to the members of the Board of UoE HPCx, and to HPCx managers. They are also reported to EPSRC and appear on the website; note that your name will be published with them. Although an entry in the comment field is optional, it necessarily gives greater weight to your feelings—without it we cannot tell why you have set a token.

Q. How do I view user mailings using the SAFE?

For PIs and project managers

Q. I have received an email saying that my project has been set up. What should I do next?
A. Here are some of the things you should consider doing; not all of them will be needed for every project.

Q. How can I get an account on the service machine for myself?
A. If you are not going to work on the machine yourself, you do not need to do this. You can administer your project through the admin website alone. But if you want a service machine account:

You will get an acknowledgment screen, from which you can return to your main page. Now (as PI) you have to accept your own request for an account - see the next question.

Q. How can I get my users registered?
A. In order to get an account, a potential user needs to know two things: your project code, and your project password. These are included in the email which SAFE sends to you, as PI, when your project is set up. The project password is not the same as your personal SAFE password; it is used only by new users when getting their accounts.

If you now accept the user, they will get an account. This is the last chance to stop someone who shouldn't be there! Take a few seconds to check the user's details, especially their email address, to make sure that they are who they say they are. Please check their nationality as well: it's your responsibility to make sure this is right.

When you accept a user, the systems team is automatically requested to create the account on the service machine. When this has been done, the user is emailed; allow a working day for this. The user can then login to SAFE and pick up their password on the service machine.

Q. How can I know when someone has registered, so that I can go and approve their registration? I don't want to have to check my SAFE account every day.
A. Login to SAFE. Then:

Don't forget the last step, or nothing will happen.

Q. How can I change the project password?
A. Login to SAFE. Then:

Don't forget the last step, or nothing will happen.

Q. How can I designate a user as a project manager?
A. A project manager can do everything in a project that a PI can do, except designate another project manager. You can designate as many project managers as you wish.

Q. How can I set up project groups within my project?
A. Project groups can be used to administer time and other resources within your project. See the discussions about the ways that projects and resources are organised.

To add users to the new project group, see the next question. A user can belong to more than one project group.

Q. How can I add users to an existing project group?
A. Login to SAFE. Then:

If the project group is using disk or tape quotas, this operation is carried out by a human, so there may be a short delay. Otherwise, it happens at once.

A user can belong to more than one project group.

Q. How can I remove a user from a project group?
A. Login to SAFE. Then:

If the project group is using disk or tape quotas, this operation is carried out by a human, so there may be a short delay. Otherwise, it happens at once.

Q. How can I administer time within my project?
A. Time is measured in allocation units (AUs), and is held in budgets. Every project group has its own budget. There are always at least two project groups in your project:

Initially, all your time is in the general group's budget. If you are happy with all your users using the same budget, you can leave things as they are.

If you wish to divide the time up between groups, you can create a project group for each group. In this case you will probably want to move all the time out the general group, since this can be used by everyone.

You may wish to give time just to a single user. This is a special case of a project group: one with only one member.

The reserve budget is provided so that if you wish you can control the use of time by your project members: you can keep most of the time in your reserve budget, and move it to the other budgets as required. We recommend that you should do this, even if you don't need to create other project groups.

Q. How can I move time between budgets?
A. Login to SAFE, and then:

Don't forget the last step, or nothing will happen.

Q. How can I allocate time to a single user?
A. As all the time in a project group is shared by all its members, the only way to reserve some time for a single user is to create a project group for that user alone.

Remember that time in the general group's budget is accessible to all, so you will probably want to move all of the project's time away from there.

Q. How can I administer disk and tape store space?
A. Start by reading the discussion of the administration of time, as the administration of disk and tape space is related to this, and is also done using project groups. The two project groups which exist in each project can also be used for administering space.

Homespace, workspace and tape archive space are administered separately. A project has an overall limit for each of these. Within that limit, every portion of space must belong to one or other of the project group quotas. Thus, to start with, all the homespace (for example) allocated to a project is either in the general homespace quota or the reserve homespace quota. Space never belongs to more than one group quota. [The reserve quota is not a real quota, in fact. It has no existence on the service machine—just in the database.]

Beyond the general and reserve quotas, you can also have quotas for the project groups which you create. But this is not compulsory. If you're thinking about using project group quotas, you need to be aware that they are implemented using Unix groups, which are only just adequate for the task.

Let's use homespace as an example—workspace and the tape archive are similar. Suppose you are project t01. To start with, one Unix group will be assigned to this project. The homespace directories for all users will be in directory /hpcx/home/t01/t01/ —this is where the general group is held. User john, for example, will have directory /hpcx/home/t01/t01/john/ as his homespace directory. (In fact, if this is the first project he joined, that's where he will log in.) Any file created in any of the directories under /hpcx/home/t01/t01/ will belong to the Unix group for project t01.

If you create a project group t01-a with no homespace quota, this will not change. But the moment you give a homespace quota to this project group, a Unix group will be assigned to it and a directory will be created for it: /hpcx/home/t01/t01-a/. If user john is a member of this project group, he will have a directory /hpcx/home/t01/t01-a/john/. Any files he creates under that directory will belong to t01-a and will be counted against its quota.

Of course, john is still a member of the general project group, so he can still create files there. If he belongs to other project groups which have quotas, he'll have directories for these as well. He can only create files in the project groups he is a member of, since he can't access the directories of the other groups. It's up to him to make sure that he creates his files in the right places, so that they get charged to the right project groups.

That's the theory, but unfortunately there are ways for users to get round this system (by mistake and on purpose), and there's nothing we can do about this, apart from changing the group IDs of files when we notice it happening. We are at the limit of what the operating system's technology can do.

You should also note that once you have instituted project group quotas, there's no easy way back. Removing them and reassigning all the files to other groups is a complex job and will require special arrangement with the system team—send a request to the helpdesk if you need to do this.

Most projects in fact use their project groups only for administering time, and allow their users to have access to all their space. You could if you wish make use of user quotas to stop individual users from taking too much space.

[Note that the above points do not apply to the reserve quotas, since they don't exist on the service machine. They're just a book-keeping fiction, and using them is cost free. We recommend this to any project which is concerned about running out of space.]

Q. How can I create a quota for a project group, or move space between quotas?
A. First, read the discussion of space administration. If you are still determined to use project group quotas, this is how.

Don't forget the final step, or nothing will happen. The act of moving quota space to a project group which has no quota set converts that project group to one with a group quota, administered by a Unix group, as discussed earlier.

Quota changes are actually carried out by a human being. Once this has been done, you will receive an email informing you. If you ask for the quota to be reduced below the current size of the files in the project group, the human will reject your request, and you will get an email saying this.

Q. How can I set a quota for a single user?
A. User disk quotas are completely separate from project group quotas. A user quota simply places a limit on the amount of space which a particular user can occupy in workspace or homespace (user quotas are not available on the tape archive). There's nothing to stop you setting user quotas which add up to more (or less) than the total space. To set a quota for a user or users:

Once again, these quota changes are carried out by a human. Once they have finished, you will receive an email.

Q. How can I see the current state of my project's time and space?
A. Login to SAFE. Then:

If a project group's use of a quota is getting close to the maximum, it is highlighted in pink.

The budget values displayed are updated every morning, and the values shown for disk and tape use are updated four times a day. For this reason, these values may not all be completely up-to-date. If there is a lot of activity in your project, the numbers shown could be significantly different from the current ones.

Q. How can I track what my project's users and project groups are doing?
A. This can be done using the Report Generator.

Q. How can I see how much space my project's users are occupying?
A. Use the Report Generator (see the previous question), and select "User disk use". The Report Generator displays the history of disk use—to see the current use, make sure that the reporting period includes the present moment. The disk and tape usage values known to the database are updated four times a day, so if there is a lot of activity in your project, the numbers shown could be significantly different from the current ones.

There's an unresolvable problem with this: if a user has an account which belongs to more than one project, the disk usage shown for that account will be the total that the account is using in all those projects combined.

Q. My project needs more space or time. How can I get it?
A. If you need more home or work space, or more tapes on the archive, contact the helpdesk. We will always receive such requests sympathetically, and it is likely that we will be able to allocate some more to your project.

If you need extra time, you should contact the research council which is funding your project. HPCx can't allocate time without authorisation from them.

Q. How can I delete a project group?
A. You can only delete a project group if it has no resources or members. You must remove all its members and all its time. Also, if it has disk or tape quotas set, it cannot be deleted; they will have to be removed first. Then:

Deleting a group involves removing its various directories. A human has to do this, so there will be a short delay.

Q. Can I temporarily stop a user from using any time in my project?
A. Yes. This is called deactivating a user. A user who has been deactivated cannot use any of your budgets. This means that they can't do any work, in effect, so we recommend that you use this facility with care.

To reactivate the users, do the same, but click "Activate" instead.

Q. How can I remove a user (or users) from my project?
A. Before doing this, bear in mind that it will result in all their files in your project being deleted. Are you sure that this is what you want? If so:

SAFE will now ask you to confirm your action. If you do, all the files and directories in your project which belong to the users will be deleted, and the users will be removed from any of your project groups, so that they won't be able to use your time. In addition, if a user does not belong to any other project, their account on the service machine will be closed.

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