---------- Forwarded message ---------- From: Sean Clark <smcl...@tamu.edu> Date: Thu, Jan 20, 2011 at 10:41 AM Subject: Re: [Bacula-users] Very low performance with compression and encryption ! To: John Drescher <dresche...@gmail.com>
On 01/20/2011 09:00 AM, John Drescher wrote: > This is normal. If you want fast compression do not use software > compression and use a tape drive with HW compression like LTO drives. > > John Not really an option for file/disk devices though. I've been tempted to experiment with BTRFS using LZO or standard zlib compression for storing the volumes and see how the performance compares to having bacula-fd do the compression before sending - I have a suspicion the former might be better.. For the original question though - not only is this normal, this is normal for programs other than bacula. I see the same thing happen when using compression with scp/ssh (and even "tar -cf - | gzip | nc" ) as well, for example. The latency introduced by pausing to compress the data into each packet unavoidably slows things down, and compression is really only useful over very slow links (or in bacula's case, only if you're more worried about disk space than backup speed.) LZO is a faster, apparently much less cpu-intensive algorithm (though it does not compress as well as zlib) - it might be that if bacula-fd had an LZO compression option better throughput might be possible while still getting some space savings. Even so, looking into some method of storage-side compression is likely to give you better performance in my experience. -- John M. Drescher ------------------------------------------------------------------------------ Protect Your Site and Customers from Malware Attacks Learn about various malware tactics and how to avoid them. Understand malware threats, the impact they can have on your business, and how you can protect your company and customers by using code signing. http://p.sf.net/sfu/oracle-sfdevnl _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
