clarification on "new member"

[redlex]

The retrospect documentation describes "new member" as follows:

 

"When Retrospect performs a New Member backup, it skips to a new member of the current Backup Set. Retrospect first looks for a member with the correct name and uses that member if it can find it. "

 

What is "the correct name"? I'm having trouble getting "new member" to cause a new tape to be used (so I can take the current tape off-site). More described in this post:

 

http://forums.dantz.com/ubbthreads/showf...&PHPSESSID=

 

thanks.

[rhwalker]

For a backup set named, for example, "BackupSet" (without the quotes), members are named:

1-BackupSet, 2-BackupSet, etc.

[redlex]

Thanks for your reply.

I know how backup members are named, but I am trying to find out what is meant by the *correct* name. i.e. which number at the front? How is it chosen?

[redlex]

The language used is just confusing. The docs say:

"When Retrospect performs a New Member backup, it skips to a new member of the current Backup Set. Retrospect first looks for a member with the correct name and uses that member if it can find it"

 

But why would a new member backup use an existing member with "the correct name"? I would image that "new member" should always create a new member in the backup set.

Example: suppose I have a backup set with the following two member:

 

1-Set A

2-Set A

 

If a "new member" backup is run, I would imagine that should always mean a new tape is created called 3-Set A. But the docs suggest that under some circumstance could such a tape already exist, but not be part of the set - how does that work? A tape can have a name but not be part of a backup set?

[redlex]

Ok, I think I've worked it out now.

It is possible to have a backup set contain more tapes than actually have data on.

For example, you can manually add as many tapes as you want to a backup set.

So I could create a set with three tapes:

 

1-Set B

2-Set B

3-Set B

 

And then do a recycle backup to 1-Set B. If my next backup was 'new member', it would look for 2-Set B (the next tape with no data on it yet), and find it in the set. Is this correct?

[rhwalker]

Quote:

---

But why would a new member backup use an existing member with "the correct name"?

...

But the docs suggest that under some circumstance could such a tape already exist, but not be part of the set - how does that work? A tape can have a name but not be part of a backup set?

 

---

Yes, let me give you an example. Sadly, a bug exists in the Macintosh version (and has for years), that was fixed years ago on the Windows version, that prevents this example from working on the Macintosh version. Even though it was fixed as a bug in the Windows version long ago, I have had an ongoing dispute with Retrospect support for a couple of years under our support contract whereby they consider it a "feature" of the Macintosh version rather than a bug, and have not fixed it. This bug makes management of a barcoded tape library impossible unless you allow the last tape to run out with no erased tapes in the autoloader, causing the last backup of the set to fail, then insert an erased tape the next time. It happens to be one of my "hot buttons", but it will serve as an example for you.

 

If you have an autoloader with barcoded tapes, management of a tape inventory is essential. Years later, when you have a pile of tapes and need to get the right one for restoring a file that was backed up 15 years ago, you need to know which barcoded tape to pull from the rack, and there MUST be a correct correspondence between bar codes and tape names. Also, when Retrospect looks at the autoloader / library, it needs to know which slot in the autoloader / library has the correct tape, and it only knows this by the barcodes.

 

To solve this problem, if you have a barcode reader in your tape autoloader / library, it is customary to barcode the tapes upon receiving them from the vendor and then "pre-erase" / "pre-name" the tapes (Retrospect > Configure > Devices). When Retrospect names the tape (which is not yet part of a backup set, even though it may have the next member name in the backup set sequence) by putting down a special header at the beginning of the tape, it associates the tape's barcode with the name. The next time it needs a new member, it will retrieve that pre-erased, pre-named barcoded tape and use it (only in the Windows version; the bug in the Macintosh version causes Retrospect to ignore the name if the tape is erased and barcoded but named, and to whimsically use whatever erased tape it wants in the autoloader). If the barcode is not found in the autoloader / library, Retrospect will ask for a tape with the proper barcode.

 

Additionally, even though your question didn't go into this part of tape naming, if you do a "new media" backup, such that Retrospect moves to a new backup in the sequence rather than adding a member to an existing one, it will append a suffix to the backup set name of monotonically increasing numbers 001, 002, etc., within brackets at the end of the backup set name.

 

Make sense now?

 

Russ