On Fri, 2 Mar 2007, Bill Moran wrote:

> That "400G with compression" is just an average.  There's no guarantee
> that you'll get 2x compression.  Personally, I find it false advertising,
> but nobody's listening to me.

I tend to agree, especially now some makers are advertising based on 3:1 
backup ratios..


I find that some LTO-2 tapes with only system and incremental backups 
(mostly logfiles, configfiles, sources and binaries, highly compressable) 
can get up to 700GB. IIRC one even topped 950GB (which I assumed must be 
wrong, but subsequent checks verified there really was that much on it), 
at which point I implemented "volume use duration" of 7 days.

On the other hand, various data partition backups full of compressed files 
regularly only manage 205GB on the same 200GB LTO-2 tapes.


It really does matter what you're trying to backup.

If in doubt: ' tar - /path/to/root | gzip | wc ' vs
              ' tar - /path/to/root | wc '


-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Bacula-users mailing list
Bacula-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bacula-users

Reply via email to