Nick,

Amanda does not, as far as I know, allow backups to write to multiple
drives concurrently. It can switch tape in a jukebox and it can swap
to a second drive unit when the first is full, but concurrent writing
isn't a feature I'm aware of.

At my site I've done something that I believe is similar to what Joshua
has done. I have an amanda server with two amanda configs, to avoid
conficts, because they run at the same time, and because I wanted to
avoid rebuilding binaries with non-standard sockets, I run one where
all DLE are local to the server and one where the amanda-clients are
all not-on-the-server. Within each config amanda does the scheduling
but I'm able to make rapid use of two drives concurrently. FYI, these
are LTO drives in 9 slot jukeboxes.



On Sat, Apr 09, 2005 at 03:13:54PM -0500, Nick Jones wrote:
> Wouldn't it still be more efficient to let AMANDA's planner take care of
> which backups go to which drives and at what times?
> 
> 
> --
> Nick 
> -----Original Message-----
> From: Joshua Baker-LePain [mailto:jlb17 AT duke DOT edu] 
> Sent: Saturday, April 09, 2005 3:06 PM
> To: Nick Jones
> Cc: amanda-users AT amanda DOT org
> Subject: RE: Large Amanda installations
> 
> On Sat, 9 Apr 2005 at 9:15am, Nick Jones wrote
> 
> > As it stands (and as far as I know) the only way to tape to multiple 
> > drives simultaneously is to use "juke" in conjunction with AMANDA.  
> > Native support for a multi-slot and multi-drive changer would be nice.
> Thanks.
> 
> That's not exactly true.  I use both drives in my changer simply by running
> two configs simultaneously.  To some extent, it's just an added level of
> parallelization.  When I had only one drive and was using 'runtapes=2', the
> backups sometimes ran well into the day.  With two drives, two configs, and
> runtapes=1, they're always done in the early AM.
> 
> As to the original question, I've got ~4.8TB of used space over 4 servers
> (out of ~5.2GB formatted space), and back it up using a 2 drive, 19 slot
> AIT3 changer.  With a new 6TB server arriving Monday, I'm looking hard at
> LTO3 changers...
> 
> --
> Joshua Baker-LePain
> Department of Biomedical Engineering
> Duke University
> 
> 
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