Bacula-users

Re: [Bacula-users] Speed of backups

2011-04-28 12:44:14
Subject: Re: [Bacula-users] Speed of backups
From: John Drescher <drescherjm AT gmail DOT com>
To: Jason Voorhees <jvoorhees1 AT gmail DOT com>
Date: Thu, 28 Apr 2011 12:41:57 -0400
> How can I know where's the bottleneck? I'm using an ext4 filesystem.
> Are these tests useful?
>
> [root@qsrpsbk1 ~]# hdparm -t /dev/sda
>
> /dev/sda:
>  Timing buffered disk reads:  370 MB in  3.01 seconds = 122.89 MB/sec
> [root@qsrpsbk1 ~]# hdparm -tT /dev/sda
>
> /dev/sda:
>  Timing cached reads:   3770 MB in  2.00 seconds = 1885.16 MB/sec
>  Timing buffered disk reads:  370 MB in  3.00 seconds = 123.20 MB/sec
>

That is expected for a hard drive purchased in 2010 or newer.

>
> First I disabled 'signature=SHA1' at my Jobs and I gained little speed
> of my backup (between 79 and 83 MB/s). Then I enabled Data Spooling
> (so attribute spooling also is enabled) and my backups became slower
> (between 36 and 45 MB/s).
>

Your benchmark does not measure random or small file performance
(smaller than a few MB). Any mechanical hard drive will not have > 100
MB/s for this. SSDs or raid will but not a regular hard drive.

John

------------------------------------------------------------------------------
WhatsUp Gold - Download Free Network Management Software
The most intuitive, comprehensive, and cost-effective network 
management toolset available today.  Delivers lowest initial 
acquisition cost and overall TCO of any competing solution.
http://p.sf.net/sfu/whatsupgold-sd
_______________________________________________
Bacula-users mailing list
Bacula-users AT lists.sourceforge DOT net
https://lists.sourceforge.net/lists/listinfo/bacula-users