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Recommend a Backup Rotation

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I'm running an SBS with Retrospect 7.5.251, backing up roughly 300GB of data to HP Ultrium 200gb/400gb cartridges using the HP StorageWorks Ultrium 448 drive.

 

Most of my data is non-compressible, so it takes up two tapes. Here's my current backup scenario, which I think could be improved:

 

2 backup sets, alternating weeks

6 tapes per backup set

On Monday, I recycle to 1-Backup A, which takes two tapes Tues - Friday I do a new member backup to [3-6] - Backup A, which backs up changes since Monday Following Monday, the recycle starts over again with a new backup set

 

Looking at the disaster recovery planning, it says I should create a new disaster recovery CD whenever I recycle the backup. It sounds like I'm recycling the backup too often. Does anyone have any suggestions on how to improve my backup routine? The main goal of the backup is off-site protection. Thanks in advance.

 

-Scott C

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Hi Scott,

 

Technically the most efficient way to backup your data would be to run normal backups nightly after the recycle, saving data to a single tape until it is full. However, this would not allow you to take tapes offsite daily, which may be what you're going for.

 

You have outlined a solid rotation, except I'm a little unclear on your last bullet; "Following Monday, the recycle starts over again with a new backup set." You said you're only using two backup sets, so you mean you'll just be swapping back and forth between A and B on a weekly basis, correct?

 

Regarding your disaster recovery question, the recommendation in the book is encouraged to prevent discrepencies from arising between the system state information on the DR disc and system state information in the backup set. You could get by with recreating the DR discs less frequently, perhaps once a month, but you do want to keep them reasonably up to date.

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Hi Foster,

 

Thanks for the response. I figured that it would be more efficient to use only one tape, but I'm willing to sacrifice and use multiple tapes for offsite purposes.

 

Your assumption is correct. I have two sets of tapes, and I rotate them weekly. Will I need a DR disc for each backup set?

 

Thanks for your help, I didnt want to find out the hard way that I haven't been backing up correctly!

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I'm back with another question about setting up a backup rotation.

 

I'll quickly restate how I want the backup to work: Every Monday I want to make a complete backup of my data, which will take two tapes. Tues - Friday, I want to do an incremental backup, using a new tape each day to be moved off site. Until my data grows, I should be using 6 tapes in this rotation. I'd also like to rotate backup sets, so I have two sets of 6.

 

I've attached a screenshot of my backup schedule. What's happening is that my backups are taking two tapes on Monday AND two tapes on Tuesday, and then they're incremental from Wed - Friday. There's nothing that goes on during the day Monday that would require two tapes vs. the rest of the week. The rest of the week takes up no more than 45GB of a 200 GB tape.

 

Can I delete the two scheduled "Recycle" backups? If I do new member backups for a week on set A, and then switch to set B the following week, will the first backup be a complete backup?

 

Thanks in advance for the help!

 

backupschedule.jpg

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Hi,

 

If you switch the Monday backups from Recycle to New Member, then Retrospect is going to ask for a new tape to continue backing up to incrementally on Mondays. You would essentially have a backup set that never ends, and wants a new tape every day. Unless you run a Recycle backup, or backup to a new backup set, Retrospect is going to increment new data into the backup set specified.

 

If a new member backup takes two tapes I would expect there to be a large number of errors in the operations log - likely compare errors. Or perhaps 'miscompared' flags for files backed up again in the original session.

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"Unless you run a Recycle backup, or backup to a new backup set..."

 

What about the fact that I'm switching my backup set every week? Every Monday I rotate backup sets. If I just had two lines above, "New Member backup to Backup A" Mon - Fri every other week, and "New Member backup to Backup B" Mon - Fri every other week, would the first backup of that week be a full backup? Because that's what seems to be happening now, the first backup of the New Member backup is a full backup.

 

There are the same amount of errors in Tuesday's operations log as there are for Monday...a handful of sharing violations for C:\System Volume Information. I dont see any compare errors.

 

Thanks so much for your help!

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Hi,

 

No, it would not be a full backup. Your Monday backups are 'full' now because of the Recycle. If you were to delete the Recycles and set both Mondays to New Member, then on Monday Retrospect would prompt you for a new tape to which it would append the files that had been changed since Friday two weeks before.

 

So if you only run New Member backups:

Week 1: Start with an empty backup set. Backup Set A runs New Member (incremental to

a new tape) every day this week.

Week 2: Start with an empty backup set. Backup Set B runs New Member (incremental to

a new tape) every day

Week 3: Backup Set A wants a new tape to add incremental data to the existing data still

in the backup set from Week 1.

 

If you run a backup to the same backup set Retrospect will only add any new and changed data. It will always compare the source data against data that is already stored in the backup. So the only way to get a 'full' backup is to have an empty backup set. This can be achieved by running a recycle backup or backing up to a new backup set that does not contain any backup data from that particular source.

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Sorry to be a bother, but I'm still here.

 

The first four days of this week, my backups have taken 2 disks each day. Each set of two disks is roughly the same size, making them appear to each be full backups.

 

My error log contains about 100 different sharing violation errors, and 99% of them look similar to the following:

 

File "E:\System Volume Information\{674d909f-0338-11db-9cd4-0016353d162a}{3808876b-c176-4e48-b7ae-04046e6cc752}": can't read, error -1020 (sharing violation)

 

This has been happening since day 1. The number of errors slowly increases as our data grows. Something that stuck out to me in the error logs for Thursday night was that one of the errors was a file not found, referring to a file that I deleted. However, I was here late Thursday night and it's possible that I deleted this file shortly after the backup started.

 

At this point, I'm debating whether to purchase a support incident to straighten this issue out. My only concern is making sure that the problem is fixed if I get approval to purchase a support incident.

 

Any suggestions or insight are most welcome.

 

*EDIT*

 

Ok, I went into the sessions tab for my current backup, and found something very interesting. I click on my E drive session for Thursday night, and it contains 109,804 files. Clicking the properties of any file I checked shows a Miscompared flag. (You called this earlier Foster, I thought that this would be in my error logs though).

 

So, what causes a miscompare? Is there a way to fix it? Most of the files we're talking about are .PSD's, .FLA's, .jpeg's or php/css text files.

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Hi Scott,

 

The files in your System Volume Information directory are likely going to be related to antivirus or similar applications. Typically the contents of that directory and be excluded from backup without any problems, but you should verify what those files are before relying on that assumption.

 

As for the miscompare flag, I believe that is a bug. I do not know what causes it, but I have several things you could try out to see if we can narrow it down.

 

Try backing up to a disk backup set rather than tape

backup with different verification methods - thorough vs. media

backup with security information disabled - (Script)> Options >More Choices> Security

 

Some combination of these settings might get around the miscompare flag being set on these files.

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I'm knocking on wood as I make this post, but my backup rotation is going smoothly through the first three days of this week.

 

I changed my verification method to thorough (from media verification), and everything appears to be working as expected. My Monday backup took two tapes, and asked for each tape back when the backup was done, as the documentation indicates.

 

Tuesday and Wednesday's backup took one tape, and roughly an hour to backup 70-80GB of data, which is expected.

 

Foster, I truly appreciate your patience and advice in helping me get everything straightened out. Thanks so much!

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