You don’t have to be a fan of Sex in the City to know that it’s important to backup your data. If you have not seen this wonderful vignette, take a moment to see what can happen if your intellectual property is not well protected.
Princeton uses a software application called Tivoli Storage Manager or TSM to back up campus computers. During the current academic year, TSM has backed up 600,000,000,000,000 bytes of stored data on 10,849 campus client accounts using 16 STK/Sun T10000 encrypted tape drives in two silos as well as eight TSM servers in two computer rooms.
The primary goal of this important TSM backup service is to protect the personal work of members of the University community from loss owing to hardware failure or inadvertent deletion.
There is a version of the TSM software for most of the computer operating systems on campus. You should take note of the fact that a new version of the TSM client software that has just been released (version 18.104.22.168) and the TSM web pages are being changed this month to reflect the new software and its installation.
You can obtain the software from the TSM web page. There, you will be able to obtain client software for: Windows XP, 2003, Vista; Mac OS X (for Macs); Mac OS X (for Intel Macs); Linux x86; and Solaris.
You are eligible to use the service if you have a Princeton netid and meet the other requirements listed at the TSM web site. There is a limited, or personal, account that is free of charge. A complete backup account is included with DeSC computers or with an account number.
The personal work documents stored on faculty, staff and graduate student workstations is backed up at no charge and with no limit on size. The definition of personal documents is based on the location of the documents (for example, the “My Documents” and “usr” folders on a Windows NT or Windows 2000 systems).
Undergraduates are provided with 250 MB of shared network disk storage that protects their data with two different backup/restore capabilities. Self-service recovery of individual files that have been deleted or damaged will be provided by the shared storage server using a “snapshot” technology, which maintains copies of changed or deleted files in a special storage area on disk. TSM backup will be used to guard against catastrophic failure of the entire shared storage system.
For those campus systems that need backup service beyond the personal documents directories, a complete backup option is available for a fee of $5.00 per month. This complete backup service encompasses all directories on all disk volumes, with the exception of a few such as Temporary Internet Files and other similarly temporary directories. A $5.00 fee applies for any system whose total TSM occupancy is less than 150GB. Since data is compressed before it is stored on TSM’s tapes, the 150 GB limit represents a much larger occupancy on a user’s disks. Usage above the 150 GB limit will be charged at $.50/GB month in addition to the $5.00 charge for complete backup. Owing to their special standardized software, campus computers participating in DeSC (Desktop Systems Council) will continue to receive their regular backups at no charge.
Some departments store their users’ personal work on a central server, and therefore do not backup individual workstations. To accommodate such departments, OIT has defined a special mechanism. If you are interested, contact OIT for further information.
What does TSM do and why does it matter?
In its most elemental function, TSM simply sends a copy of the files on your computer to a server for safekeeping. TSM compresses the data with a proprietary algorithm on your computer before forwarding it to the TSM servers. A separate TSM password for your data, different from anything else you use, also helps to ensure that your data is safe during the transmission process. Further protection comes from storing the data on servers that are kept in computer rooms with secure limited access and environmental controls.
Most backups occur automatically, using TSM’s scheduler. This is a service or daemon, depending on your operating system, that wakes up every twelve hours and communicates with the TSM server. Most desktop computers have a backup window that runs from 6:30 pm to 6:30 am, with the bulk of the backup initiations occurring in the first half of this window. This is a startup window only. Some backups may run into the morning hours after 6:30 am. Laptops are not usually left on overnight, so their backup window is during the day, typically over lunch.
In order to use TSM effectively, it’s necessary to understand how the backup process operates. TSM is a true incremental process; it doesn’t need to run a ‘full’ or base backup every month or week. If a file has been backed up once, TSM will not back it up again – it’s already on the server.
If you make frequent changes to a file, it is important to know that TSM will store the final version as well as the last three versions. If you need to restore an older version, TSM will not have it unless you gave the file a different name.
Know that all of the inactive versions will be removed from the TSM server’s storage (30 days by policy). The active versions will NEVER, EVER be deleted. In other words, if a computer is not backed up for 30 days or more, the backup in storage will contain all of the files that the client computer had on it when it was last backed up. The files will remain there indefinitely unless you email email@example.com and have them removed.
It may be important for you to know that the data on machines that are now inactive (surplused or even destroyed) but were backed up by TSM can still be restored. Indeed, a backup program wouldn’t be of much good if it weren’t able to restore data from a computer that no longer existed. You can have that data removed by sending e-mail to firstname.lastname@example.org.
How are files restored from the TSM backup service?
The key, of course, is backing up, because otherwise restoring files will be impossible. If you are experiencing a crisis, please call the OIT Help Desk (8-HELP) or e-mail email@example.com. The actual procedure for restoring files is well documented in the OIT KnowledgeBase.