-------- Original Message --------
Subject: Re: [Networker] Faster Cloning. By saveset or volume?
Date: Fri, 26 Sep 2003 15:54:40 -0400
From: George Sinclair <george.sinclair AT noaa DOT gov>
Reply-To: george.sinclair AT noaa DOT gov
To: "Novello, Guy" <GNovello AT phcs DOT com>
References: <8E621BA187DA3B4499DE50AEAB85421B01E9833F AT walexc01.phcs DOT com>

Davina was correct. There really is no such thing as cloning a volume
because NetWorker will insist on wanting to clone all the savesets even
if they carry over from or onto other volumes. If it was "true" that you
could "truly" clone a volume then the unfortunate side effect would be
that you'd end up with some incomplete savesets, most likely the first
and last ones written to the tape that you were cloning.

The magic question now is whether or not the two commands to clone the
savesets on the tape:

nsrclone -s server -b pool volname
nsrclone -s server -b pool -S -f file

are equivalent in speed. I think you will find that they are because
NetWorker will optimize the order as Davina pointed out, but personally,
if I want to clone all the savesets on a tape, I find it easier to just
clone using the volname rather than creating a list of the ssids and
using the -S -f file name technique.

George

"Novello, Guy" wrote:
>
> George,
>
> Thanks making my thoughts clear. Currently, I clone using  nsrclone -s server 
> -b pool -S -f file
> My question was, would it be faster to clone with  nsrclone -s server -b pool 
> volname
>
> I think I will just try it and see.
>
> Regards,
> Guy
>
> -----Original Message-----
> From: George Sinclair [mailto:George.Sinclair AT noaa DOT gov]
> Sent: Friday, September 26, 2003 2:39 PM
> To: Legato NetWorker discussion; Novello, Guy
> Subject: Re: [Networker] Faster Cloning. By saveset or volume?
>
> I seem to recall that this got into this issue of de-multiplexing versus
> maintaining the multi-plexing. Then again, that may be have been the
> difference between running the nsrclone command with a list of saveset
> ids (on the command line with -S or via an input file as -S -f file)
> versus iterating over the list one at a time. I think if you iterate it,
> the savesets would have to be un-multiplexed, but if you don't iterate
> it one at a time then the multi-plexing is preserved. If that's true,
> then it seems to me that cloning the entire volume would have to be
> faster because it would not have to de-multiplex anything, but if you
> did it by saveset, one at a time, then it would, unless you ran it using
> an input file with all the savesets in there.
>
> So, my question would be: is running nsrclone with an input file that
> contains all the savesets tantamount to cloning the whole volume in
> terms of over all time. In other words, which of the following is
> faster:
>
> nsrclone -s server -b pool volname
> nsrclone -s server -b pool -S -f file
>
> where file contains all the saveset ids on the volume.
>
> I mean, both operations should amount to the same thing, but I'm
> thinking that cloning the volume using the first command is easier and
> could not be slower than the second.
>
> George
>
> "Novello, Guy" wrote:
> >
> > Hello Everyone,
> >
> > I seem to remember a discussion over which was the faster way to clone. I 
> > am currently
> > using the ssid, but I am thinking it may be faster cloning the volumes.
> >
> > Has anyone tested this?
> >
> > Thanks in Advance!
> >
> > Guy
> >
> > --
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