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Table of Contents
Overview
Only servers and faculty and staff computers (profiles and D: drives) are backed up at SILS. If your files are not in one of these locations, you must choose other options for backing up and protecting your data. All public machines in SILS are completely erased three times a year and replaced with a clean build of the OS and software. Any files saved only on these machines, such as files in the "My Documents" folder or on the Desktop, will be deleted without backup when this happens! It is imperative that users follow at least one method of backup.
You can back your files up to a server (such as Duck or Isis ) or to removeable media (such as a USB data key , External Hard Drive , or CDs or DVDs ). Plan a backup strategy for your files. It might help to see an example of a backup strategy for a hypothetical user.
Server Backup
If you save files to your folder on Duck (the H: drive on the SILS Lab machines), your files will be backed up every night. You can put your files on Duck by mapping to your folder as a drive (this is done automatically when you log into a SILS Lab machine as yourself, or you can [ http://sils.unc.edu/itrc/its/faq.php?id=4701 ] map a drive on your laptop ) or by connecting to Duck via [ http://sils.unc.edu/itrc/its/faq.php?id=4627 ] FTP and transferring the files that way. You can use your Duck space for file backup, but please keep your total space used below 200MB . (In other words, you will probably not be able to back up all of your data on Duck.)
If you ever lose or accidentally delete a file from Duck, it can be restored from backup. To get a file restored from backup, contact the Help Desk (962-8188). Backup tapes are only saved for two weeks , so if you lose a file, contact the Help Desk as soon as possible so that your backup is not overwritten. Your file will be restored to Duck.
If you save files to Isis (your AFS space or ITS H: drive), your files will be backed up. You can put your files on Isis by connecting to Isis via [ http://sils.unc.edu/itrc/its/faq.php?id=4629 ] FTP and transferring the files that way. You also have a space quota on Isis (an amount of disk storage that you can't exceed). To check how much space you have, go to [ https://onyen.unc.edu/ ] onyen.unc.edu and click "check disk space usage" in the lefthand column.
If you lose or accidentally delete a file from Isis, it can be restored from backup. To get a file restored, you must [ http://help.unc.edu/?id=3663 ] contact ITS, but contact them right away; they don't save backups for very long!
External drives can hold between 5GB and 500GB of data, depending on the size of the disk and the drive you're using, so they are very useful for backups. Like regular hard drives, external drives can fail, so never save your only copy of a file on a drive. Use the drive for backup by making a copy of a file that is also on your Duck folder, Isis space, laptop, etc. When an external drive is attached to your computer, it appears as a drive on your computer and can be used in the same way as your primary hard drive.
USB data keys are small drives stored in a plastic case that hold anywhere from 128MB to 16GB of data (and perhaps more by the time you're reading this; as a new technology, they are evolving quickly). They are sold at the [ http://www.store.unc.edu/ram/hardware/ ] RAM Shop and work with any notebook or desktop system with a functional USB port. When you insert them into the USB port of the computer, they appear as a drive on the computer, and you can move files to and from them just as you would to a physical drive in the machine. These are a good choice for backing up files that change frequently, because you can overwrite old versions without having to waste media, as you would with a CD-R.
CDs and DVDs are more stable media than diskettes or external hard drives, and they hold a large amount of data, so they may be a better choice for backing up files that are not likely to change, such as music or photos. (On the other hand, they can only be used once, whereas USB keys and external hard drives can be reused.) Even CDs sometimes fail, and of course they can get scratched, broken, lost, etc. So if you want to archive a file (make a copy and take it off of your server space or laptop), it's a good idea to burn two CDs of the file, just to be safe.
For more information, please see our page on [ http://sils.unc.edu/itrc/its/faq.php?id=4592 ] burning CDs .
Backup Strategies
Remember that if you back up a file, then delete the original, you don't have a backup anymore!
To develop a backup strategy for your data, ask yourself some key questions about your various files. As you'll see from the suggested strategies, not all files need to be backed up the same way. You will probably come up with a combination of different strategies for different types of files.
|
Question |
Answer |
Suggested Strategy |
|
1. Can I afford to lose these files? |
a. Yes. |
You don't need to back these files up. If they are ever lost, you can just recreate them or do without them. Think carefully about whether this is really true. |
|
b. No. |
You'll need to make sure they're backed up. See question 2. |
|
|
2. Where are my files? |
a. On my laptop. |
You need to back these files up yourself. See question 3. |
|
b. On Isis or Duck. |
These files are already being backed up. You don't need to back them up yourself, but see question 4, answer c. |
|
|
c. On an external drive or other removeable media. |
Be sure that you have more than one copy of the file, especially if it is on an external hard drive or a USB key. |
|
|
3. How often do these files change? |
a. Never or almost never (like music or work from past semesters). |
CDs or DVDs are a good choice for backup. While they're not reusable, these files don't change much, so you just need to make one backup, and you won't waste media. Periodically check your backup CDs to be sure they are still okay. Making two sets of CDs is not a bad idea. |
|
b. Every week or so. |
Servers, external hard drives, or USB data keys (and/or rewriteable CDs) are a good choice for backup. They're reusable, so when your files have changed, you can overwrite the old versions without wasting space or media. |
|
|
c. Constantly-every day. |
Again, servers, external hard drives, and/or USB keys are a good choice, but servers may be the better choice because they are backed up daily. See question 4, answer c. |
|
|
4. How much work can I afford to lose? |
a. A few days' worth to a week's worth. |
Back up your files once or twice a week. If you lose data, you can go back a few days to your last backup, restore your files, and pick up from where you left off without too much trouble. |
|
b. A day's worth. |
Back up your files every day. If these files are on your laptop, backing them up to a server is one good method; an external hard drive is another. If your files are on a server, they will be backed up daily. |
|
|
c. None! (It's my master's paper!) |
If you are making a lot of updates to a critical file on a frequent or daily basis, it's not a bad idea to keep a copy on a server and on an external hard drive, USB key, your laptop, etc. You may spend a little more time doing this, but if something catastrophic happened, you wouldn't be sad that you had a little extra security for your file. |
Example Backup Strategy
Joanne does most of her school work on the computers in the SILS Lab. She has a Web site on Isis that she works on regularly. She has a set of personal projects on her laptop that she works on every two months or so. She has a music collection of about 20GB. She's working on her master's paper.
Joanne decides that she can't afford to lose any of her files. She could replace her music collection from the source if she had to, but it would be time-consuming.
Joanne's backup strategy:
-
She doesn't need to worry about backing up her school work, because she saves that in her Duck folder (her H: drive) when she's in the SILS Lab, and Duck is backed up nightly.
-
She doesn't need to worry about backing up her Isis Web site, because that's already being backed up, too.
-
The personal projects on her laptop don't change very often, so she decides to back these up to her external hard drive. Every time she works on her personal projects, she updates the contents of the drive so that she doesn't lose her work.
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Her music collection may have files added, but the files themselves aren't being edited. She burns copies of the mp3 files to data DVDs. Every six months, she sorts her music folder by date and burns the newest files to DVD.
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Finally, Joanne decides that she can't afford to lose a single keystroke of work on her master's paper. She works on this in the SILS Lab and saves the work to Duck, but she also makes an extra copy of the paper on a USB data key every time she works on it. This way, even if her Duck copy were to be lost or damaged before the next backup, she would have a backup of her most recent work.