Yet another backup question

[WapleSpunK]

I thought I had it figured out. I was going to use Migo and do a Mirror of my source drive E: to my backup USB drive F:

However, I did a test with a temp directory to see what happened. I first did a mirror backup and it copied the data over like I thought. When I deleted some of the files from E: it deleted them from F: which is to be expected. However, I'm now thinking this isn't the best way to do a backup because what if I accidentally deleted a file, the backup runs, it deletes it from my backup drive and now the file is gone forever. Same if a file becomes corrupt, it'll save the corrupt file to the mirrored drive.

So is mirroring not a good way to back up my data? Would doing the regular compressed incremental backups avoid that situation or could the same thing happen? the main reason I'm wanting to not do that sort of backup anymore with my current Nero software is because that backup gets bigger and bigger and my drive becomes full every 3 or 4 months and I need to empty it again and start over.

This is just confusing the crap out of me.

[onstill]

Ive run into that issue before as well. My recommendation is a program like http://www.karenware.com/powertools/ptreplicator.asp and when you configure it there is a setting to not have it delete files on the destination drive. if you do a 2 drive rotation and clear one of the drives every month or so (whenever it starts to get too full) youll beat both birds with one stone.

[WapleSpunK]

What about cases where you rename files? Will it leave the old ones there?

I guess mirroring isn't a bad thing because there are times where you'll actually want to delete files, and I guess there's no way for your PC to know if you did so accidentally or on purpose.

Maybe I should just have it mirror weekly and not daily and do manual ones when I know I put new stuff out.

[ThaMan]

The way I would handle the situation is, I would go and rename the folder you are backing up to (mirroring to) once a week. That way, you have a snapshot in time on that day. Then the next time you mirror the drive, the software will recreate the directory structure from scratch.

YOu have to make sure you have enough space to hold the backups.

Also, onstill's idea of having two external drives is an excellent one.

We use a tape backup at work, but it uses the same principals as using external drives. In our backup scheme, I do Differencial backups daily on Monday, Tuesday, Wednesday and Thursday. Each with a different tape. You could do these in different folders, or rename the folder each morning before you start work. (A differencial backup is the data that is chanced since the last FULL backup, not the last backup. In my case, that is any file that has been changed since the last Friday)

Then on Friday, I do a full Data backup. I keep 4 separate tapes for Full Data Backups. One for each friday of the month.

Then once a month, I do a monthly full Data Backup. I have three of those tapes.

If you were to take these practices and adapt them to your external drive, you would do a diff backup on Mon, Tues, Wed, and Thurs. Say your backup folder on the external drive is called DIFF_Backup. When I came into work on Tuesday morning, the Monday Diff Backup would be complete. The files in the Diff_Backup folder would be current files from Monday's work. I would rename the Diff_Backup folder to Diff_2009-02-08 (the date of the backup). Then create a new Diff_Backup folder. (I believe it will create the new folder automatically if it doesn't exist, but you need to check for sure).

Do the same thing each morning until Friday. On Friday, the backup routine would backup into a folder called Full_Backup. On Monday morning, I would rename that folder to FULL_2009-02-09. Then create the FULL_Backup folder.

The Monthly backup I would do in a folder called MONTHLY_Backup, and rename to MONTHLY_2009-02-28.

What you have to decide when you are doing backups is how much time can you afford to lose. Because, anything between your last backup and NOW is what you will lose if you have a system failure. We have decided at work, that one day's work is expendable in the worst case scenereo. Backing up more frequently than that is too costly to justify at this time. Now, that may not be the case as servers come down in price, and our productivity increases. Soon we may decide to mirror servers, which would put us at the minutes of work lost point.

All in all, I have 13 tapes in our rotation.

[ThaMan]

Oh, and I only do a full SYSTEM backup when I add software or do a change to the server. It takes more than one tape, so it is a major pain in the ass. I also have annual tapes, but we won't go beyond that.

[Kheldin]

SyncToy has an option to copy data and leave files when deleted.

Check it out.. it might work for ya.

http://www.microsoft.com/downloads/details.aspx?FamilyID=c26efa36-98e0-4ee9-a7c5-98d0592d8c52&DisplayLang=en