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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Hi Brad,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> Thanks for your valuable inputs, Is
there any way you achieved these figures 4.3 GHz, 1 GB RAM, 80 GB SATA-I hard drive?
For 25K clients with 24 hour lease time.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Regards<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Mani<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
dhcp-users-bounce@isc.org [mailto:dhcp-users-bounce@isc.org] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Brad Dameron<br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, October 17, 2008
1:52 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">dhcp-users@isc.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: Guidelines for Sever
dimensioning</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div id=idOWAReplyText48423>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>We are a large ISP and have several
hardware configurations. I can tell you the following configuration and what it
is doing in production right now.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Pentium 4 3Ghz, 1 GB RAM, 80Gb SATA-I hard drive.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>It is currently handling a little over 25,000 clients with
a 24 hour lease time. This is a mixed OS type of client.</span></font><o:p></o:p></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>In our lab we did many tests and with a AMD X2 6000+ with
4GB of DDR2 800 and a Gigabyte i-RAM ramdisk with 4GB on it we were able
to handle upwards of 350k clients. This was using Nominum's dhcperf test too
with a 24 hour lease time. 200k customers was achievable with a 250GB SATA-II
Seagate enterprise drive.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>We also had modified the source code slightly to adjust a
hash setting. You can find that in the list email. Just search for my name.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The AMD processor was ultimately the best for handling DHCP.
This is due to how it handles memory. </span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Also one huge performance enhancement on our linux servers
was due to the dhcp logging itself. If you use syslogd you need to look at
putting a hypen in front of the path/filename like:</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'># DHCP message into seperate file<br>
local6.*
-/var/log/dhcpd.log</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Or if you don't log to a specific file and log to messages:<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>*.info;mail.none;news.none;authpriv.none;cron.none;
-/var/log/messages<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>If you use syslog-ng then in the conf change:<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>options {<br>
sync (0);<br>
<o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>TO:<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>options {<br>
sync (20);<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>What this does is to only write 20 lines to the log at a
time. Instead of writing every line individually. This saves on a lot of disk
activity and heavily increases DHCP performance.<o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><br>
<o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Brad Dameron<o:p></o:p></span></font></p>
</div>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Clearw're<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Senior Systems Engineer<o:p></o:p></span></font></p>
</div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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face="Times New Roman"><span style='font-size:12.0pt'>
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<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
dhcp-users-bounce@isc.org on behalf of T Manikandan-Q3926C<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thu 10/16/2008 11:24 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">dhcp-users@isc.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> Guidelines for Sever
dimensioning</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi,</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Can anybody help me in dimensioning the DHCP server?</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I Have X number of clients to be supported by the server.
How will I obtain the CPU, RAM and Hard disk calculations?</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Say for X number of clients each client takes 4 transactions
to get the IP from the DHCP server, considering each packet of size 576 octects,
takes 576*4= 2304 octects</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>For X clients considering 100% client attached during busy
hour it will be ( 2304 * X ) octects, or (2304 * X *8/3600) bytes per second,
which is the bandwidth but, </span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>How should the dimension be for the CPU, RAM and Harddisk. (
Taking account for OS , especially for RHEL),</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Regards</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Mani</span></font><o:p></o:p></p>
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