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DavidHertzberg

Effectively enable Backup to multiple Backup Sets at the same time

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The OP in this thread in the "Product Suggestions—Mac OS X" forum proposes a modest enhancement to Retrospect that would effectively enable Backup of the same Sources to multiple Backup Sets at the same time.  Once this enhancement is in place, an administrator could overlap a single Backup script run with a Transfer Snapshots or Transfer Backup Sets script run started as little as 5 minutes afterward.  This enhancement would no doubt also be valid for Immediate operations in Retrospect Windows, although I don't mention those in the linked-to OP because Retrospect Mac converts all Immediate operations into scripts with a single-occurrence schedule.  In reading the linked-to OP, be aware of the following terminology differences: a Backup Set is termed a Media Set in Retrospect Mac, Transfer Snapshots is termed Copy Media Set in Retrospect Mac, and Transfer Backup Sets is termed Copy Backup in Retrospect Mac.

 

The enhancement makes use of the multiple-activity-thread capabilities first released in Retrospect Mac 8—and (without an announcement) also in Retrospect Windows 7.5 as multiple-execution-unit capabilities—and documented in the Retrospect Windows User 's Guide.  These capabilities are officially not available in the Desktop Edition, but in fact I did all the testing recounted in the linked-to OP on my Desktop Edition copy of Retrospect Mac 12.5.  Using Desktop Edition, you must AFAIK in the same execution of the "backup server" first go to Preferences and in Execution—General bump "Execution units" (per page 420 in the Retrospect Windows 11 UG) up from the 1 that it defaults to every time the "backup server" is started.  Then, whether you are using a Server Edition or the Desktop Edition, you must set the Execution Unit (per page 290 and many other places in the UG) to e.g. 1 for the Backup script/operation and e.g. 2 for the Transfer script/operation.  To be on the safe side, although I don't know exactly how the enhancement will be implemented by the Retrospect Inc. engineers, you should make sure the Transfer script/operation starts at least 5 minutes after the Backup script/operation.

 

You should be able to test overlapping Backup and Transfer right now, except that—as discussed in the third paragraph of the linked-to OP—only the files that are already entered in the Catalog File are copied by the Transfer.  Fixing that by forcing the Transfer of a Source drive to lag behind its Backup copying is why the proposed enhancement is necessary.

 

If you need this capability, and you want Retrospect Inc. to do the enhancement, per this thread you must indicate your need by posting or Liking in either this thread or the linked-to thread.

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One thing that is made clear in the OP in "Product Suggestions—Mac OS X" is that it turns out that overlapping a Backup script run with a Copy Media Set script run from the Backup's Destination does not appreciably slow down a Backup script run whose Source(s) are "client" hard disk drives.  I'm sorry I forgot to mention that in the OP in this thread; it should whet your appetites considerably.

 

P.S.: Why, you may well ask, did using "Media Set Blue" simultaneously—as I did on the morning of 31 December—as both a Destination for the "Sun-Fri Backup" script and a Source for the Copy Media Set (Retrospect Mac terminology for Transfer Snapshots) script not slow the backup appreciably?  The reason is that, at least when the Source for a Backup is a hard disk drive, the gating factor is primarily speed of directory traversal on the Source drive—not LAN speed or Destination drive speed (because the Destination drive is not traversing directories).  That may not hold true if the Source is an SSD, but I'm not about to spend money upgrading an Early 2011 MacBook Pro which became officially "obsolete" when the ball fell at midnight on 31 December in Times Square.

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