ntbackup help please :S

[techyphil]

Im trying to schedule an incremental backup. Thanks to advice from other posts about incremental rather then FULL im determined to go down that route.

Now, im going through the wizard and ive selected incremental > next >

now it says "If the medium you are using to back up your data already contains backups, choose one of the following options...

Append this backup to the existing backups

Replace the existing backups"

Btw: Using TAPES.

Now, I assume its Append as replacing it wouldnt then increment as there isnt a file there to do so, therefore taking just as long as a FULL backup.

Which should I choose? I dont have time to test either of them out atm as we have no backup in place. Thanks very much for any advice!

Cheers

[Andi]

Append will add the backup onto the end of the tape until there is no longer any room.

An incremental backup will backup any files that have changed since the last full backup.

The two aren't related in any more ways than that.

Unless I've misunderstood the question.

[Andi]

My advice would be:
Run a weekly full backup on it's own tape.

Then set daily incrementals to append to another tape. The incremental backups will naturally be smaller, therefore you are more likely to fit them on one tape.

This may well change depending on the capacity of your tapes and the amount of data you are backing up.

If you have no backup done then do a full as soon as you can until you have worked out a backup plan.

[NetworkGeezer]

Then set daily incrementals to append to another tape. The incremental backups will naturally be smaller, therefore you are more likely to fit them on one tape.

It's better to have them on different tapes so that a problem during one backup doesn't take out the other.

There's nothing about incremental backups which says you have to append to end of existing backup. This should only be the case if you can't get hold of any more tapes of the right capacity.

These days incrementals are done more for time considerations than cost of media

[techyphil]

Thanks Andi,

So Incremental only backups the differences and sticks that in a seperate file. So restoring backups...

Does it ask for the full backup tape then ask for the additional tapes with the changes on it?

[Andi]

It won't ask for them, but yes that's the basic idea for a standard file restore.

Restore the full backup first, then the each individual incremental since.

[mrforgetful]

Then set daily incrementals to append to another tape. The incremental backups will naturally be smaller, therefore you are more likely to fit them on one tape.

It's better to have them on different tapes so that a problem during one backup doesn't take out the other.

There's nothing about incremental backups which says you have to append to end of existing backup. This should only be the case if you can't get hold of any more tapes of the right capacity.

These days incrementals are done more for time considerations than cost of media

I was under the impressions that's what was bad with Incremental Backups? That if one was broken then none worked.

[DMcCoy]

Do not use incremental. Use differential. You only need two tapes to work then, the last full backup and the latest differential. Incremental relies on too many media.

[techyphil]

Thanks DMcCoy and everyone,

I google "ntbackup tutorial" etc etc "ntbackup differencial" and it always come up with the microsoft help page on setting up full backups.

I wish there was a tutorial on this sorta thing. Prehaps edugeek could house something in the future to help other memebers with reguards to backing up.

Thanks again, your advice is much appreciated. I shall see what I can do

[ChrisH]

Best advice I can give is stay away from the GUI its a complete pain in the arse. I run all my backups from a script and run the backup from the cmd line. The only thing I use the GUI for is to do the file selections.

[petectid]

Append will add the backup onto the end of the tape until there is no longer any room.

An incremental backup will backup any files that have changed since the last full backup.

The two aren't related in any more ways than that.

Unless I've misunderstood the question.

An incremental backup will backup files since the last incremental or full backup. The backup type you describe is a differential backup.

As D McCoy explains it is easier to use a full backup followed by differential as you only need the full backup and the last differential to restore your files this is much easier than using 5+ tapes to restore your data.

[techyphil]

Thanks petectid...

Those scripts look a tad complex but im sure I could figure it out after some time spent looking into it.

I think the cmdline method maybe easier. I shall see how this goes first.

Cheers

[NetworkGeezer]

I was under the impressions that's what was bad with Incremental Backups? That if one was broken then none worked.

Not quite. It is prefereable to have all incremental tapes availible for a complete restore but for a partial restore it isn't necessary.

If say you Tuesday incremental backup got corrupted you could still restore files from other days of the week.

[NetworkGeezer]

As D McCoy explains it is easier to use a full backup followed by differential as you only need the full backup and the last differential to restore your files this is much easier than using 5+ tapes to restore your data.

The problem of doing it this way is that the further you get from the normal full backup then the more files you have to backup.
This means on Wednesday or more likely Thursday you could loose much of the time advantage that was originally sort. Media capacity could be a worry if you have a very limited budget.

[petectid]

Network Geezer, its swings and roundabouts really, we seem to manage well here and test our data restore on a bi-monthly basis. The difference between our last full backup and the Thursday differential backup takes about 1.5 to 2hrs to complete so it’s not an issue. We have different tapes for all backups and do not append data. As long as a system works for you it’s adequate but they do need to be tested occasionally.