SENS Computing Policies and Practices

Introduction

We subscribe to the same computing policies as are explained on UB's Information Technologies web page. Failure to comply with these policies can lead to loss of computing privileges.

As far as user information collected on this web site is concerned, we subscribe to UB's Privacy Policy.

Because Science and Engineering Node Services (SENS) is concerned about providing quality computing support, we realize that circumstances may arise that will necessitate exceptions to some of the policies described in the following sections. Please email any questions about such exceptions to nodehelp@eng.buffalo.edu or nodehelp@nsm.buffalo.edu, but be aware that exceptions are made on a case-by-case basis, and a request does not guarantee an exception.

What follows are rules that will ensure that your SENS computing experience is a positive one, as well as some good common-sense practices that can make your life easier and your time more productive.

SENS Statements and Recommendations

UNIX Personal Disk Space

As part of your SENS UNIX account, you get disk storage space that is for your personal use. Your home directory, which is where you will store most of your data, as well as system and application configuration files, will have a directory path of the form /eng/home/[UBITName] for Engineering users, and /nsm/home/[UBITName] for Natural Sciences and Mathematics users.

The following policies and guidelines apply to your home directory:

All SENS users have a disk area known as a "home directory" with a fixed usage quota of 300 MB, which cannot be increased on an individual basis (we raise the quotas of all users equally as we add new disk space). This includes personal web page space, which is stored in a directory named public_html under your home directory, but does not include your SENS email inbox space. Check your quota once in a while by using the quota command. If you suddenly find that you cannot create new files, or files are zero-length or truncated, you are probably over quota. In such a situation, you will need to either delete old files, and/or compress infrequently-used files with the compress or gzip commands.
We do not enforce quotas on email inboxes as we don't want to cause people to lose incoming email. However, we will send you a message if your inbox gets to a size that we consider too large, and expect you to delete some items to reduce the size promptly. Account deactivation can result from ignoring this request.
We value your privacy, and consider your home directory, and the files under it, to be your property. In general, we will not look in it unless we have your permission, such as if we are helping you solve a problem. On rare occasions, if there is a significant system or user problem, and we believe your directory might be part of the problem, we reserve the right to visit your home directory, but will take every effort to minimize the intrusion and protect your privacy. The same policy goes for your email inbox. However, research and class space belongs to your instructor or advisor, not you, and is subject to their permissions and privacy rights.
Additional disk space can be provided through the use of class directories, research disks, or disks on individual faculty, staff, or research computers. Contact your instructor or faculty advisor if you are in need of more disk space, and they can make a request for one of these directories if they feel the request is legitimate. These areas will have quotas that do not count against your home directory quota, but neither will they increase it.
For your convenience, we use the NFS protocol to make your disk space accessible on all UNIX and Linux systems in our Node, including our timeshare pool. We also use the Samba program to simulate a Microsoft Windows server, so that you can access your data from personal computers in our Node, including the Citrix servers.
Users are encouraged to run the use update command once a month, and to not make changes to their personal login files, as described on this page.
Your data is backed up according to the policies and procedures listed later in this document.

UNIX Temporary Directories

These policies apply to the UNIX temporary directories /tmp and /var/tmp:

Temporary directories are not backed up. Ever. If a file is deleted from a temporary directory, it's gone forever. Really.
Any files in temporary directories on the public lab UNIX systems will be deleted as part of their nightly cleanup/reboot process.
Any files in temporary directories on the SENS timeshare systems that have not been used within the last three (3) days are deleted on a nightly basis. Use these areas only for short-term work, and not as a storage area. Also, we will not tolerate the use of touch or similar commands as a means to make these files look like they've been recently accessed.
In emergency circumstances, such as the temporary directory filling to capacity, we reserve the right to delete all files in the temporary directories without warning.
Do not use the temporary directories on the SENS timeshare systems as "dumping grounds" for large amounts of data.
Please clean up temporary files when done. For example, scripts that create temporary files should delete them at the end of the script.

SENS Unix Labs

The following policies apply to the systems in the SENS UNIX labs:

All public workstation labs are either open 24 hours or have access via swipe card readers, except when undergoing maintenance (usually during intersession gaps).
All UNIX systems in public labs are rebooted nightly between 3:00 and 3:30 a.m. Users who are logged in will be given a warning message at 3:00 a.m., and are encouraged to log out promptly to avoid loss of work. The actual reboot time is staggered over a half-hour interval among the lab systems to avoid excessive network traffic.
Eating or drinking in public labs is strongly discouraged.
Users should not remote log in or run remote network commands to other public lab systems.
Users who lock the screens on lab system consoles will have their processes killed without warning by the system administrator.
Persons committing acts of vandalism or theft in public labs will be prosecuted.

Failure to comply with these policies can lead to account deactivation.

Timeshare Systems, including Unix, Linux, and Citrix

The following policies apply to our timeshare systems, including the Solaris and Linux timeshare pools and our Citrix environment:

Please run only one CPU intensive job on a particular timeshare.
Do not "hog" system resources, such as using multiple CPUs, running jobs at a high priority level, or performing excessive disk I/O in temporary directories. We have many users trying to use the same resources; courtesy and cooperation are essential.
If you have a need for large computing resources, please send email to nodehelp@eng.buffalo.edu or nodehelp@nsm.buffalo.edu and we will try to accommodate your needs.
We reserve the right to terminate processes that we feel are having an adverse effect on the system. In such cases, we will attempt to contact the user prior to terminating the process.
Direct connections from off-campus are not permitted. Preferred methods of accessing our timeshares are via on-campus systems, using a VPN link, via the UBUnix timeshares, or by dialing in to the UB PPP modem pool, as described in more detail on this page.

Failure to comply with these policies can lead to account deactivation.

Unix Backup Policies

Backups are performed primarily for purposes of disaster recovery. We are able to use them to recover data that has been accidentally deleted or corrupted, but this capability should not be abused.
We do not guarantee that we will be able to recover your data; however, we will make every reasonable effort to do so.
Based on when your file was created and deleted, we may not be able to recover it; for example, a file on a system must exist overnight, as that is when backups are performed.
We are not always able to recover the most recent version of a file.
We will try to restore your data in a timely matter, and can usually do so within one working day; however, system emergencies take priority, so on rare occasions you may have to wait up to several days for your data to be recovered.

Backups are performed every night. Once per month, a "full" (or complete) backup is performed on every system. Once per week, an "incremental" (or partial) backup is performed, backing up files that have changed since the last monthly backup. Every night during the week, incremental backups relative to the previous weekly or monthly backups are performed. Daily backups are retained for 10 days, and weekly and monthly backups are retained for six months. The granularity of these backups are nightly for 10 days, and weekly after that, as described above.

If you need to have a file restored, click here to submit a request for this service.

University at Buffalo - State University of New York

Science & Engineering Node Services (SENS)

Quick Links