Revised Backup Strategy Scheduling

[jtaylor]

I have recently inherited responsibility for my company's backup solution. We are currently running Retrospect Workgroup Backup 5.0.238 on Mac OS X Server 10.2, using an Ecrix VXA-1 drive. The primary question I have concerns the automated job scripting and scheduling.

 

My previous backup experience is with a different vendor's backup product, running on Windows 2000. The terminology and scheduling options were somewhat different, so please forgive me if I'm unclear as to some of the functional details of Retrospect. Also, for simplicity I'm omitting less relevant information here, e.g. details about our off-site storage rotation.

 

The previous backup administrator used the following backup strategy. Using a total of 8 tapes (WEEK 1 through WEEK 8), every week a tape is swapped on Friday and a recycle backup is performed at night. For each of the subsequent six days of the week (Sa-Th) the same tape is used and normal backups are performed. (Each single tape has the capacity to hold a full week's backup.) There are eight backup sets, one for each week, and eight backup jobs, one for each week. Each of the 8 backup jobs has 7 schedules, to run the appropriate job on a given day of the week, every 8 weeks (using the repeating interval scheduler). The scheduling aspect in particular seems unnecessarily complicated to me, and I would like to simplify if possible.

 

Here are the goals for the improved strategy. Prefer to minimize the administrative complexity of having eight backup sets and 56 schedules (8 jobs times 7 schedules). Must ensure maximum reliability and safety of data, specifically concerned here with prevention of overwriting previous week tapes. Prefer to continue to swap tapes weekly rather than daily. Must continue to backup 7 days/week, and preferably be able to recover from any day during the previous 2 months.

 

This is my proposed strategy. Create one backup set to include all eight tapes. Create one backup job with two schedules. The first schedule will run a recycle backup every Friday. The second schedule will run a normal backup every other day of the week (Sa-Th). It seems to me that the biggest concern with this strategy is the possibility of overwriting a previous week's tape by forgetting to swap the tapes on Friday. The previous Windows backup software I used had a media overwrite protection period to address this problem so that, for example, a tape could not be "recycled" (Retrospect terminology here) within a given number of days. How should I best handle this in Retrospect?

 

Are there any other factors or considerations which I should take into account with my proposed strategy? I'm open to input from anyone here regarding modified or alternative strategies which meet the criteria outlined above. Thanks in advance for your time and feedback!

 

Jeremy Taylor

 

--

 

There are only 10 types of people in this world...

those who understand binary and those who don't.

[AmyJ]

Quote:

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Each of the 8 backup jobs has 7 schedules, to run the appropriate job on a given day of the week, every 8 weeks (using the repeating interval scheduler). The scheduling aspect in particular seems unnecessarily complicated to me, and I would like to simplify if possible.

 

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Each week will only require 3 schedules - not 7. A Retrospect calendar week starts on Sunday - so the schedule needs to accomodate the split week. An example for one of the backup sets:

 

Every 8 weeks on Friday, Recycle Backup to Backup Set 1, starting Friday, 4/11/2003

Every 8 weeks on Saturday, Normal Backup to Backup Set 1, starting Saturday, 4/12/2003

Every 8 weeks on Sunday-Thursday, Normal Backup to Backup Set 1, starting Sunday, 4/13

 

The next backup set starts with...

Every 8 weeks on Friday, Recycle Backup to Backup Set 2, starting Friday, 4/18/2003

 

Quote:

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This is my proposed strategy. Create one backup set to include all eight tapes. Create one backup job with two schedules. The first schedule will run a recycle backup every Friday. The second schedule will run a normal backup every other day of the week (Sa-Th). It seems to me that the biggest concern with this strategy is the possibility of overwriting a previous week's tape by forgetting to swap the tapes on Friday.

 

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Actually, the biggest concern is that you'll only use 1 backup set -- rather then 8. You should always rotate at least 2 backup sets, if only to keep a complete set off site. Another consideration is that tapes fail, break, wear out, etc. - with more then one backup set you have the security of knowing that another backup set is availabe should one fail.

 

Retrospect will not automatically overwrite (erase) just any tape in the drive - it must be the exact tape that Retrospect is asking for.

 

If an 8 week rotation is overkill for you, consider making a shorter interval, such as a 4 week rotation. This will give you 4 complete sets of data. With 4 remaining tapes, you can use them for replacements when tapes start to fail or you could have 4 month-end tapes which recycle themselves every 4 months.