Back up strategies

Upchurch

Papa Funkosophy
Upchurch
Joined
May 10, 2002
Messages
34,265
Location
St. Louis, MO
So, I recently suffered through the most painful crash I've ever had with the near loss of up to a month's worth of work. I got very very lucky.

I'm putting into place a back-up plan into place composed of three layers. The first layer is daily back ups to DVD-RW's (I have five labeled "Monday", "Tuesday", etc.). I'm using Window's backup system set to the "Daily" setting for this. The second layer consists of weekly full system back ups to an external hard drive, again using Window's back up system. The external drive lives off my work site. The last layer, I just zip up my critical work files and copy them to our development server. I do this after I put a sizable change into place in those files.

I know this can't be the best system. I know there must be better backing up software. I know there is something I'm not preparing for.

Tell me what I'm doing wrong.

eta: I should have added that I use a laptop as my principle machine so it travels outside of the office on nearly a daily basis.
 
Well that's more or less similar to what we do, and what we do is far far more than what most people do.

We have an incremental backup to DVD+R every night. This obviously backs up everything that's changed. We have two sets, and one set runs each night; each night anything that's changed in the last 36 hours is backed up. This means we can restore almost any version of a file that ever existed, as long as it existed overnight at some point. Woebetide the next person to create a file in the morning, delete it ten minutes later, then ask me if I can get it back from the backup.

We also backup to removeable hard drives. There are three sets of these, and overnight every night, they duplicate the entire server, which takes a couple of hours or so. As there are three sets, and they are changed every day, that means there is always one set in the backup server, one in transit, and one offsite.

We use EMC/Dantz Retrospect, and I have no complaints about it. The scripting system is a little idiosyncratic, but not complicated. That said, our system does take about ten minutes every day to swap scripts around and suchlike, but that's including the time it takes to swap discs around as well.

Oh, and the laptop is your principal machine, unless you're using it out of moral duty, or to make a point.;)

Cheers,
Rat.
 
Mac Users might want to buy a copy of this:
http://www.takecontrolbooks.com/backup-macosx.html

It covers backup stratgies that would apply to anyone, but the software recommendations are Mac only.

Also, if you tend to have broadband access with your laptop you might want to look into something like box.net. You can do small incremental type backups to them and then even if your laptop is stolen you will have access to something.

http://www.box.net/
 
Rat said:
Oh, and the laptop is your principal machine, unless you're using it out of moral duty, or to make a point.;)
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Don't think I'm NOT! When, oh when, will we break free from the tyranny of towers?!?

We shall over come....


ahem. Do you think using Windows' back up tool is sufficent, or would you recomment something else?


eta: and at this point, Upchurch reads the part about EMC/Dantz Retrospect. Ah, thanks. I'll look into it.
 
Basics of backing up (IMHO).

1) Offsite copies, covered
2) Redundancy, covered.
3) Frequency, covered.
4) Historical, not covered.
5) Testing, not covered.
6) Versioning, not covered.
A more comprehensive plan would involved dual copies every night, one offsite, one onsite, but in your case I don't think it's worth the effort.


Some people like to have a history that spans a year, or more, for example. This covers you if you delete a file, and are not aware of the fact for a year or so. That is, you back up your data every night, but if you delete a file, and aren't aware of the fact, you will not be backing it up any longer. This also gives you a history for a file that might be changed over time.

A lot depends on what you are doing, and what you are backing up. For some applications, versioning is important.

It doesn't hurt to actually test if you backups are any use. The Windows registry can be very important sometimes, for example.

Windows backup is fine for many cases, but don't have files open while you back them up.
 
Upchurch said:
ahem. Do you think using Windows' back up tool is sufficent, or would you recomment something else?
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I think Windows own backup is quite adequate. It does everything I want, anyway. It can be a bit funny to set up schedules for, but once they're done they're done. YMMV of course, but I'm not sure what another backup program could do that NTBackup doesn't (other than hit you in the wallet).

Edited to add:
a_unique_person said:
Windows backup is fine for many cases, but don't have files open while you back them up.
Click to expand...

Aha. Why not?
 
It can't back some of them up while they are open, or they might be changing while being backed up. Eg, a database. You want the database shut down while it is being backed up. Or, use the database backup tool, not Windows backup.
 
Hmm, that never occurred to me. I presume that's a problem for all backup programs, though? You can either skip open files or copy them regardless and hope that they're in some sort of sensible state when you try to restore them. (Or have some cunning strategy like ARCHIVELOG mode)
 
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It doesn't hurt to actually test if you backups are any use. The Windows registry can be very important sometimes, for example.
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This can't be emphasised enough. I worked at a place that did regular daily and weekly backups. One day the accounting software screwed up its data and the backups didn't work.

Major oops. The IT guy looked pretty stupid. I couldn't believe he didn't test his backups.

Question: Isn't the deal with not backing up open files mostly to do with the way the Windows OS works? I know that trying to open a single file on multiple machines usually results in an error that the file is in use.
 
No, the problem with open files is true on all file systems. A file that is open is in a state of transistion, backing it up will most likely miss some data being written to the file and most likely will get an incomplete file that will register as corrupt.

File locking on network drives is important on all OS's. If a file is not locked properly while someone is working on it, then when another person opens the file whoever saves last will overwrite the others work.

locking is also important in multi-user databases. Look at issues with page and row-level locking in databases.
 
a_unique_person said:
It can't back some of them up while they are open, or they might be changing while being backed up. Eg, a database. You want the database shut down while it is being backed up. Or, use the database backup tool, not Windows backup.
Click to expand...
Mine (XP Pro SP2) has a feature called Shadowfile or something similar, that allows you to back up a copy of files in use. It may not be up to date to the second of back up, but I think it's supposed to be close.
 
Upchurch said:
Mine (XP Pro SP2) has a feature called Shadowfile or something similar, that allows you to back up a copy of files in use. It may not be up to date to the second of back up, but I think it's supposed to be close.
Click to expand...

Note if there isn't room for the shadow copy on the system backup will run in standard mode and skip open files. Also the read-only copy of the open file may still be in a transistional phase, meaning the backup version will be seen as corrupt (many files open late at night, typical backup time, were left open by users -- they aren't changing. In this situation shadow copies works great.)

This requires SP2 or Windows 2003.

http://technet2.microsoft.com/Windo...b07e-4996-b611-c75a59b976c21033.mspx?mfr=true
http://technet2.microsoft.com/Windo...d224-47ee-8f6e-65103fb63e231033.mspx?mfr=true
http://support.microsoft.com/kb/104169/
 
kevin said:
Note if there isn't room for the shadow copy on the system backup will run in standard mode and skip open files. Also the read-only copy of the open file may still be in a transistional phase, meaning the backup version will be seen as corrupt (many files open late at night, typical backup time, were left open by users -- they aren't changing. In this situation shadow copies works great.)
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Good to know. Generally speaking, I shut down everything but my browser and IM while doing daily back up. I shut everything down for the full system back up (or I will make sure that I do now).
 
Kind of off the subject, I have a funny backup story. A few years ago I went to a big barn sale, part of the contents of which were the remains of a business that did computer consulting, and other computerized record keeping. Lots of old software, books, etc. There also were piles and piles of old 5 1/4 inch floppy disks from the XT and AT era, containing important backups of data and programs. Remember, these folks were doing this for a living. So of course they backed up frequently. So how did they do it? They used Microsoft backup on 360K DD disks, and occasionally even on single sided disks, formatted as 1.2 megabyte HD, to save money. I picked up a pile of the disks free. None of them worked, or course. So much for backing up.
 
I don't use a laptop, I just use a RAID configuration on my computer. 2 hard drives, one backs up the other automatically, nothing simpler than that.
 
WildCat said:
I don't use a laptop, I just use a RAID configuration on my computer. 2 hard drives, one backs up the other automatically, nothing simpler than that.
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This isn't really considered backup, it's considered fault tolerance. Traditionally backups allow you to recover historical files. I.e. if I backup to new media each night I can do a restore from previous nights.

If you have a program that writes a corrupt file, the redundant drive will also contain a corrupt file. You'll lose the data. That isn't a backup.

You're protected against drive failure, not application failure or user error.

Also it isn't unheard of to lose two drives. House catches on fire you have no backup of your data (this is why offsite versions are a good idea.)
 
I usually check the rearview mirrors and the street on both sides of my driveway and backup slow.
 
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