Resources
Data Backup on Department Systems
The University of Arizona Computer Science Department provides computing systems for CS faculty, staff, and students. Operating systems supported include Linux, Windows and Mac OS X. The variety and number of computing platforms that exist in the department necessitate different backup schemes. Users should familiarize themselves with the following information in order to ensure that all important data files are protected against loss.
Don't assume that all directories on all systems are backed up. The person ultimately responsible for your data is you. If your data is extremely important, please discuss your situation with Lab staff personnel. When in doubt, e-mail lab.
Backups are currently retained for two months--but retention may be shortened if storage resources are not available to meet demand.
See our help page on restoring files from snapshots for detailed instructions on how to restore your own lost or mistakenly deleted files.
Student Instructional Systems
Students enrolled in any CS course will receive an account for use on Lectura (the department's main instructional Linux server) and the instructional Linux systems (located in GS 228 and GS 930). Our file server Titan serves the files for all student home directories. Your home directory will be mounted automatically when you log in to lectura or any of the instructional machines.
Titan is mirrored*** daily to a remote system for disaster recovery purposes.
The primary file recovery mechanism is a feature called a snapshot. The snapshot allows students to restore their own lost files. Student files may also be restored from remote storage (in extraordinary cases).
Students using lectura and the instructional lab workstations should access and store their user files in their home directories (rather than local directories on the workstation). Files in local directories on the lab workstations (i.e., /tmp) are not backed up and may not be protected from access by other users.
Faculty Assigned Office Systems
Faculty in the CSc Department receive accounts on the main instructional server (Lectura) and many other Linux systems within the department including their office workstations. Our file server Zuni serves the files in all faculty home directories as well as cvs and project directories.
Zuni is mirrored*** daily to a remote system for disaster recovery purposes.
The primary file recovery mechanism is a feature called a snapshot. This feature allows faculty to restore their own lost files. Files may also be restored from remote storage in unusual cases. However, this procedure is time consuming and should only be requested if absolutely necessary.
Faculty using departmental supplied workstations should access and store files in /home or /cs/project areas. Under Linux, your home directory will be mounted automatically when you log in. Under Windows you will see your home directory as the H: drive.
Files stored on local Windows drives are backed up nightly upon the request of the user. The user's workstation must remain powered on and booted into Windows overnight at least one day per week, in order for backups to complete properly. Special arrangements can be made to do a backup during working hours**. Backups, particularly from a laptop using wireless, may take several hours to complete.
Our Windows backup software, Retrospect, commonly keeps backups for every day of the last week, one for each week in the last month, and one backup for each month after that--as long as there is room for storage. Retention may be shortened if storage resources are not available to meet demand. Do not count on any backups being retained for longer than one year.
Files stored locally on a Faculty Linux workstations or research machines can also be backed up nightly on request. For a backup of local files to execute, the system must be running Linux at the scheduled time. A user may exclude files from backup by placing them in subdirectories of a directory named do.not.backup. Additional exclusions may exist for files such as .mp3 or .mp2 and vmware image files.
Certain key infrastructure machines such web servers are also backed up.
RA/TA Assigned office Systems
RAs and TAs in the CSc Department receive accounts on the main instructional server (Lectura) and many other Linux systems within the department including their office workstations. Accounts in the CSC Windows domain are only created if research projects require it. Our file server Titan serves the files in student home directories, while the file server Zuni serves the files in all cvs and project directories.
Titan and Zuni are mirrored*** daily to remote disk for disaster recovery purposes.
The primary file recovery mechanism is a feature called snapshots. This feature allows students to restore their own lost files. Files may be restored from remote storage in extraordinary cases. However, this procedure is time consuming and should only be requested if absolutely necessary.
RAs and TAs using department workstations should access and store their user files in their home directories (rather than local directories on the workstation). For those with Windows accounts in the CSC domain, the home directory appears at the H: drive.
Files in local directories on the department workstations (i.e., /tmp or /scratch ) are not backed up and may not be protected from access by other users.
Windows files stored locally on a workstation are not backed up.
RAs and TAs frequently change office locations. Office changes usually entail a change to a new desk with a new computer, while old computers are reassigned.
Data left on the /scratch partition of any desktop machine is not guaranteed to be available after the move and should not be used for storage of important data. The same goes for data on the local drives under Windows.
Data files on local drives are subject to deletion during the cleanup of the machine in preparation for assigning it to a new user.
It is not acceptable to store your data on the /scratch partition of someone else's machine, even if that machine used to be yours. If the user currently assigned to this machine needs the space, the lab staff will delete your files to make space available for the current "owner" of the machine.
Data is absolutely the most precious commodity we possess. If you lose your data, not only are you hurt, but your research, and therefore your research advisor, may be impacted. The person ultimately responsible for your data is you. When in doubt, e-mail lab.
Staff Assigned Office Systems
Staff in the CSc Department receive accounts on the main instructional server (Lectura) and other Linux systems within the department including their office workstations. Our centralized file server, Zuni serves the files in all staff home directories.
Zuni is mirrored*** daily to remote disk for disaster recovery purposes.
The primary file recovery mechanism is a feature called snapshot. This feature allows staff to restore their own lost files. Files may be restored from remote storage in extraordinary cases. However, this procedure is time consuming and should only be requested if absolutely necessary.
It is recommended that staff access and store files on the central file server. Under Linux, your home directory will be mounted automatically when you log in. Under Windows you will see your home directory as the H: drive.
All staff PC's are backed up nightly*. Staff should know where their Windows applications store any critical data files in order to expedite file restore requests**. Please feel free to contact lab for assistance in this matter.
Our backup software, Retrospect, (primairly used for Windows and MacOS backups), keeps backups for every day of the last week, one for each week in the last month, and one backup for each month after that--as long as there is room for storage. Do not count on any backups being retained for longer than one year.
Miscellaneous Systems within the Department
Users of various research systems within the Department should note that these systems are not backed up. Users are expected to store important files in their home directories (which are backed up) and move these to the appropriate research systems for use.
Linux machines in the CS labs (as opposed to office assigned workstations) are not backed up. Data that is saved to local directories on lab machines will be periodically deleted by administrators.
Notes
* Nightly backups for individual Windows and Mac OS machines are performed Monday through Friday. Weekends are reserved for backing up central servers.
**Requests for file restores require that the user provide the file name, file location, and last time that the file was known to exist.
***Mirror means that when a file is deleted on the source machine it will soon be removed from the mirror system. This means that the mirror is not a good recovery method for file deletions.
Last updated October 18, 2012
by John Luiten
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