Backup to disk, then tape

[mfilby]

I have Retrospect 5.0.x for OS X, an internal, 400 GB RAID 0 array, and an external Ecrix VXA 15 tape auto-loader. I backup over 15 servers with 300 GB of data nightly. The drive array is new, and was purchased with the thought of running monthly full backups and daily incrementals to disk, then weekly full backups and daily incrementals to tape of the disk-based backups. This is relatively common practice anymore with the price of hard drives. I've found in my experience, however, that Retrospect is incapable of reading the catalog of a disk-based backup file while writing the incremental changes to tape. Is there any way to do what I'm asking?

 

Put in another way, I want to do disk-based backups for greater reliablity, speed and accessibility. I want to create tape backups from the disk-based backups for off-site storage. Simple, right?

 

-Marc Filby

[mcswgn]

Quote:

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Marc Filby said:

I've found in my experience, however, that Retrospect is incapable of reading the catalog of a disk-based backup file while writing the incremental changes to tape.

 

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I don't know what you mean by this. If you mean that Retrospect won't do incremental backups of the file backup set, you are correct. If one bit in any file changes, the entire file is backed up again. So when the file backup set has a small incremental backup "appended" to it, the subsequent tape backup will rewrite the entire file backup set to the tape, not just the "changes". In this scenario it really doesn't make sense to ever use anything other than a recycle backup when you are writing to the tape.

 

This is something I really wish Dantz would add--the ability to intelligently use a disk as a "staging area" for tape backups when client connections are slow. Like having a large on-disk buffer that could be filled first from the slow sources and then sent to the tape via a fast local connection.

 

If you wanted to play around some you could try an Internet Backup Set. I've never used them, but they store their data in "segments" rather than a single file. If you set the "remote" ftp server as the loopback address 127.0.0.1, then you should be able to trick Retrospect into writing those segments to the local disk. In theory then the tape backup would only write the new segments when it did an incremental backup. You would want to look at the efficiency of the backup done this way as compared to a more typical file backup set and you would also want to think long and hard about exactly how a restore would work with such a system before relying on it.

[natew]

Hi

 

 

 

This is a pure hack but it will get you what you are after. Do your initial backup to an FTP server (on the internal lan) using the "Internet" backup set type. Then do your incremental backups of that data. FTP backups are kept in much smaller files so you will get the incremental dump to tape you are looking for -

 

Nate

[mcswgn]

Quote:

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mcswgn said:

If you set the "remote" ftp server as the loopback address 127.0.0.1, then you should be able to trick Retrospect into writing those segments to the local disk.

 

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Someone on the Retro-Talk mailing list (and the email is not in front of me so I'm afraid I can't say who) just posted saying the loopback address won't work, but that the actual IP address will. I don't know why and it's a pity as it's less efficient not using the loopback address.

 

[rcfinders]

I thought Marc was asking a question about something I would like to do also . . .

 

I started my backup on a hard disk. At some point I would like to declare that hard disk full (skip) and switch my incremental backups to DVD -- without starting all over again with a full backup that would take up 30 DVD's. However, I don't see a way to do that. When using Skip Retrospect only offers a choice of other hard disks. If you try to change the backup set of an existing backup it wants to start all over again with a full backup. True? Or am I as confused about this as with most things about Retrospect?

 

Dave

[natew]

Hi

 

Retrospect has to handle the data differently for every backup media type. As a result you can't mix and match that way. Unfortunately If you want your backup on DVD, you need to start with DVD.

 

Nate

[icmb]

So if Retrospect cannot mix and match media, can I choose to do incremental backups to disk

 

I backup 60 machines to a non-robot DLT, but would like to do the same thing to RAID

 

My RAID works without any problems but only adds full backups for every machine every time (even after checking through the catalogue of past backups!), while the DLT does incremental additions automatically. So my gain in speed is lost by the increased traffic of full backups

 

Ian

 

[natew]

Hi

 

The matching criteria and matching process are identical no matter what backup set type you use. Are you backing up all of your machines via file sharing or Retrospect client when you backup to the RAID? This can happen when you backup via filesharing.

Is the RAID local to the backup machine?

 

I think we should try to quantify this a bit more clearly. Create a file backup set and save it on your RAID. Then set up a script to do a normal backup of 1 client machine 3 times in one night. The following morning check the session contents and verify that the entire machine was backed up every time.

 

Nate