Networker

Re: [Networker] Undesirable speed backing up to adv_file device.

2004-01-16 19:34:07
Subject: Re: [Networker] Undesirable speed backing up to adv_file device.
From: Byron Servies <bservies AT PACANG DOT COM>
To: NETWORKER AT LISTMAIL.TEMPLE DOT EDU
Date: Fri, 16 Jan 2004 16:34:00 -0800
On Jan 16, 2004, at 2:38 PM, Ungaro, Matt wrote:

 We have a Linux (Redhat 9) system running Networker 7. The hardware
is an Aberdeen (http://www.aberdeeninc.com) systems Backup Monster
with 8
120GB hard disks in a RAID 5.

<snip>

RAID 5 isn't the fastest RAID, though it is the safest.  Is your
partition spread across all 8 drives?  Are the drives on separate
controllers and/or PCI busses?

When backing up clients on the internal network, I am
maxing out writing to the disk device at 11MB/s. For the DMZ,
sometimes I
reach 8MB/s.

<snip>

The system itself is a P4 with 512 MB RAM.

<snip>

I doubt the system is swapping, but 64 sessions is a few and you might
want to max out your ram to increase the linux cache.

I am also allowing 64 simultaneous target sessions to the adv_file
device. Any tips on increasing speed would be greatly appreciated.
Thanks in advance!

The first thing you need to do is figure out how fast your disks can
write 64 different files.  You can do this by running 64 concurrent
'dd' commands at the same time, say:  "dd if=/dev/zero of=/path/file1
count=5000" (but 64 of them at the same time to different files). Time
how long each one takes to estimate throughput.  Or use 64 concurrent
'bonnie' sessions (a streaming disk performance tool available for
linux) and look at the output.

Once you know how fast your disks are capable of writing, then it is
time to look at how fast you are getting data from your network and
whether there are any bottlenecks there.  Start with the disks, though.

HTH,

Byron

--
Note: To sign off this list, send a "signoff networker" command via email
to listserv AT listmail.temple DOT edu or visit the list's Web site at
http://listmail.temple.edu/archives/networker.html where you can
also view and post messages to the list.
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=