daily backup: 5 scripts or 1?

[blair]

We're going to backup to two 120 GB external Firewire drives, rotating them off-site. I'm not sure about the best way to set this up. Would appreciate general feedback about my strategy (see below), as well as responses to my specific question.

 

 

 

SPECIFIC QUESTION:

 

 

 

We want to do daily normal backups. I'm trying to think about running 5 weekly scripts (Monday, Tuesday...) vs. 1 script that runs daily. If we do 5 separate scripts -- rather, one script to five different destinations (each destination a separate file backup onto the hard drive, right?), then there will be five almost identical copies of the backup, right? That is, each new media, recycle or initial backup will yield five identical copies, plus new/changed files over the five days of the week. Is this right? If we run one normal/incremental script daily, we get just one copy of each file.

 

 

 

Is there any advantage to the 5 separate destinations? Obviously it will occupy much more disk space than one daily incremental script/destination.

 

 

 

HERE'S THE GENERAL STRATEGY:

 

 

 

Assume we'll rotate the two hard drives weekly, with script schedules offset by one week. Otherwise, each hard drive setup is "identical." Right so far?

 

 

 

I figure/hope that each drive will hold three or four "copies" of our backup, that is, we can use the drive as an archive. So, suppose each month I set up a new destination, then increment to that destination for a month. That way, we can go back three or four months if necessary, with a fifo (first in first out) strategy to clear up space each month for the next month's backups. Does this make sense?

 

 

 

Am I right that keeping the previous month as an archive means I'll actually have to creat a new destination each month? (Not that this is a big deal timewise....) Can I just do a new media backup with file backup sets? (I've never backed up to hard drives before. We're doing backup rather than duplicate.) Or does this just mean going into the script, creating a new destination on the hard drive (e.g. "October 2002")?

 

 

 

I'm not sure about the rate at which we create new data to backup (or old files get changed), thus, how quickly our backup sets will grow. I suppose it's possible that I'll have to do a recycle backup every other week rather than just increment for the whole month; or that I'll only be able to keep one or two rather than two or three past months as archives.

 

 

 

Does anyone see any problems with organizing things this way, or anything I'll need to look out for as I set this up?

 

 

 

Thanks for the feedback!

 

 

 

Blair

[AmyJ]

In reply to:

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Is there any advantage to the 5 separate destinations? Obviously it will occupy much more disk space than one daily incremental script/destination.

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Yes, having multiple, redundant backup sets provides an extra measure of security should one of the sets go bad (become corrupt).

 

 

 

In reply to:

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Assume we'll rotate the two hard drives weekly, with script schedules offset by one week. Otherwise, each hard drive setup is "identical." Right so far?

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Yes - also assuming you have different backup sets for each hard drive.

 

 

 

I figure/hope that each drive will hold three or four "copies" of our backup, that is, we can use the drive as an archive. So, suppose each month I set up a new destination, then increment to that destination for a month. That way, we can go back three or four months if necessary, with a fifo (first in first out) strategy to clear up space each month for the next month's backups. Does this make sense?

 

In reply to:

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Redundant backups are always the way to go.

 

 

 

In reply to:

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Can I just do a new media backup with file backup sets? (I've never backed up to hard drives before.

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Yes, you can schedule a New Media backup for once a month. However, Retrospect will give them names automatically based on the original set name. For example, Backup Set A would produce, Backup Set A [001], then Backup Set A [002] and so on for each New Media backup.

 

 

 

In reply to:

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I suppose it's possible that I'll have to do a recycle backup every other week rather than just increment for the whole month; or that I'll only be able to keep one or two rather than two or three past months as archives.

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There's no way to know until you start running your backups.