Re: [Networker] 2 Part Question

2007-05-15 12:46:43
Subject: Re: [Networker] 2 Part Question
From: Darren Dunham <ddunham AT TAOS DOT COM>
Date: Tue, 15 May 2007 09:37:34 -0700
>> Can someone explain the cloning process to me as to why it would be
>> more efficient to do a restore from a clone pool tape, and why this
>> would be a good idea to use the cloned tapes at a disaster recovery
>> test site to speed up things?

> If you clone on a saveset-by-saveset basis, you demultiplex that
> saveset and create a single chunk of data to read, leading to improved
> restore performance (think of it as defragmenting your tape backups).
> However, there's been recent discussion on this list which suggests
> that there are ways in which the clone backup isn't demultiplexed, in
> which case there would be little benefit apart from redundancy and
> confirmed reliability.

Non-demultiplexed cloning happens if you pass multiple savesets into
nsrclone (instead of running them one at a time), and the savesets are
relatively multiplexed.  Demultiplexing the savesets takes more time
than straight cloning, so the time requirements may not allow you to do

Darren Dunham                                           ddunham AT taos DOT com
Senior Technical Consultant         TAOS  
Got some Dr Pepper?                           San Francisco, CA bay area
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