Tell me if this is a good idea...

[ocaptain]

Hey Everyone...

 

We have an XServe running Retrospect, backing up to an external 1TB Firewire 800 drive.

 

I performed a full backup of the server and all our workstations onto the drive (which I named BACKUP).

 

I then took a second drive, called it BACKUP-2 and copied all the data from BACKUP to BACKUP-2

 

I ejected BACKUP and renamed BACKUP-2 to BACKUP, so now I have two drives with identical names and identical data.

 

My question: if I perform weekly rotations, i.e. every Friday swap them out and take one drive offsite, will I be getting complete backups on both drives? I assume I will since the catalog is kept on the external disk and the snapshot of current files on the machine will be compared to the snapshot of the computer on that particular drive.

 

Thanks for your input on this!

 

-Anthony

[rhwalker]

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I ejected BACKUP and renamed BACKUP-2 to BACKUP, so now I have two drives with identical names and identical data.

 

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but they have different volume IDs, so Retrospect knows that they aren't the same.

 

Also, you have not indicated whether you have done a "file" backup or a "removable disk" backup. Which? That information is important in order to be able to answer your question.

 

Russ

[CallMeDave]

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but they have different volume IDs, so Retrospect knows that they aren't the same.

 

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Actually, for locally mounted physical drives, Retrospect _can_ become confused if both drives have exactly the same amount of capacity.

 

Why name them the same? No matter which Type of Backup Set you use (File or Removable Disk) Retrospect can be configured to deal properly with Destinations with unique names.

[Mayoff]

If this is a disk backup set, you will confuse Retrospect. You can not have a single catalog file pointing to 2 different disks with the same member name. Both identically named disks will eventually become out of sync with the catalog.

 

It is ugly and a bad idea. Totally unsupported from my point of view.

[ocaptain]

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Why name them the same? No matter which Type of Backup Set you use (File or Removable Disk) Retrospect can be configured to deal properly with Destinations with unique names.

 

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Hey Dave... I named them the same so if I skipped a day or in the case of not being in on the weekend Retrospect would see the disk and back up to it without having to worry about odd or even days, etc.

 

I *am* using a FILE based backup, and what I want is to have full backups on each disk without having to worry about skip-a-day problems... Are you implying that I can setup both DISK1 and DISK2 as destinations, and both sets will have complete copies and not just partials, i.e. I would need to have both disks handy in the event of a restore? And, if I do a DISK1 and DISK2, should I have DESKTOP1 and DESKTOP2, LAPTOP1 and LAPTOP2, etc. as the actual backup sets on each disk?

 

I ask this because I don't believe it was fully clear in the manual, doing what I'm trying to do.

 

Thanks for your help!

[ocaptain]

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If this is a disk backup set, you will confuse Retrospect. You can not have a single catalog file pointing to 2 different disks with the same member name. Both identically named disks will eventually become out of sync with the catalog.

 

It is ugly and a bad idea. Totally unsupported from my point of view.

 

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Hey there!

 

There is a unique catalog file on each disk, so each local catalog refers to it's own local backup set ... obviously, one catalog can't account for two different sets of media so I don't think that'll be a problem. And, the system appears to be working, but I came here for that ever valuable second opinion :-)

 

So if you consider this "ugly and a bad idea", tell me what the "PhD in Backup" would recommend in the scenario I'm talking about.

 

Thanks!!!

 

-Anthony

[twickland]

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If this is a disk backup set...

 

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You never did answer Russ's question avove about which kind of backup set you are using: Removable Disk or File. Perhaps you just breezed past that, as well as the qualifier that Robin Mayoff preceded his answer with, which may explain your flip and obnoxious reply to him.

 

All types of backup sets except for File backup sets store their catalogs on disk media, separate from where the data is stored. It would indeed be a terrible idea to have different backup set media pointing toward the same catalog.

 

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There is a unique catalog file on each disk, so each local catalog refers to it's own local backup set.

 

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Here, I notice that you have inadvertently given us the answer to Russ's question. You are using a file backup set.

 

While you seem to be able to get by with your arrangement, I think it's still a bad idea to have two different backup sets and media with the same name. Too many opportunities for confusion at a time (such as a disastrous data loss) when you may be least able to afford it.

 

Here's what I would do: use two separate backup sets, as Retrospect is designed to do. List both sets as sources in your backup script, and write two schedulers to back up to the two different sets on alternate weeks.

 

If you wanted to be able to back up to either set, depending on which is available, you can set both schedulers to back up on the same days beginning one minute apart. The go to Preferences> Media Request and set an appropriate timeout for media. Retrospect will then back up to whichever backup set's media is available, and will time out (and log an error) for the one that's not.

[ocaptain]

Thanks, Twickland...

 

That last suggestion is probably the most reliable given what I am trying to do... I had been trying to manage a way to not have errors in the log, though we would know these are "okay" errors, but I think I'll move in that direction.

 

Have a great week, and a Merry Christmas!

 

-Anthony