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View Full Version : Where's a good site for Linux tweaks?



Stef
06-17-00, 01:59 AM
I just got Linux Mandrake up and running up on my system, got LILO to dual-boot between Windows 98 and Linux. Now I just want to start tweaking this Open source stuff :-) Where are some good places to visit on the web for info on Linux?

n2drums
06-17-00, 11:31 PM
Originally posted by Stef:
I just got Linux Mandrake up and running up on my system, got LILO to dual-boot between Windows 98 and Linux. Now I just want to start tweaking this Open source stuff :-) Where are some good places to visit on the web for info on Linux?


I have the same situation here ... Madrake 7.1, win 98 se dual boot..

besides the usual suspects (linux.com, linux.org, slashdot, etc...)
a good place to start might be: http://www.pcquest.com/linux/guide.asp
but i haven't checked it out yet

hope this helps! Let me know if that site is any good

Matt

Stef
06-18-00, 01:41 AM
Thanks for the post :-)

That site was good, but I am looking for a site that detailed kinda like those HOWTO sites but written so that normal people ( and NEwbies ) can understand the concepts behind the tweaks.

Bouncer
06-20-00, 06:22 PM
Here ya go...seems more like a clearing house, but, it's a start!
http://www.linuxnewbie.org/

Regards,
-Bouncer-

------------------
"Yeah Baby, YEAH!!!"

quickfoot
12-10-00, 05:53 PM
The first thing I would do would be optimize it for broadband.

There is a misconception that Linux comes optimized for broadband, while it is more optimized than windows it still doesn't perform like it can.

I went from 100 KB/s down to 300-400 KB/s down after changing the default tcp windows.
http://www.psc.edu/networking/perf_tune.html#Linux

I set my window to the size in the windows 2000 patch.

------------------
Microsoft Certified Systems Engineer

FreeBSD - The Power To Serve (http://www.freebsd.org)

Stef
12-10-00, 10:34 PM
Originally posted by quickfoot:
I went from 100 KB/s down to 300-400 KB/s down after changing the default tcp windows.


Thats cool, I've done a lot of research concerning Linux and broadband. I've found some cool tips and tweaks too http://www.speedguide.net/ubb/biggrin.gif

This is what I've added to my rc.local script, these are the settings which I feel give me the best TCP/IP performance.

# Enable always defragging protection
echo "1" > /proc/sys/net/ipv4/ip_always_defrag
# Set TCP FYN packet timeout value to 30ms
echo "30" > /proc/sys/net/ipv4/tcp_fin_timeout
# set TCP socket keepalive time to 1800ms
echo "1800" > /proc/sys/net/ipv4/tcp_keepalive_time
# Enable TCP window scaling
echo "1" > /proc/sys/net/ipv4/tcp_window_scaling
# Enable TCP selective acknowlegments
echo "1" > /proc/sys/net/ipv4/tcp_sack
# Enable TCP timestamps
echo "1" > /proc/sys/net/ipv4/tcp_timestamps
# Set default receive window to 64KB
echo "65535" > /proc/sys/net/core/rmem_default
# Set max receive window to 64KB
echo "65535" > /proc/sys/net/core/rmem_max
# Set default send window to 32KB
echo "32767" > /proc/sys/net/core/wmem_default
# Set max send window to 32KB
echo "32767" > /proc/sys/net/core/wmem_max


From the documentation I've read over at the Pitsburg Supercomputer Center the Linux TCP/IP stack is limited to a 64KB receive window. You also need to enable TCP window scaling in order to use a receive window over 32KB. I find the settings above to work best with my DSL line.

Since I'm not running a server I only need small receive window to streamline the uploading process. I also reduced my transmit queue of my NIC by using ifconfig eth0 txqueuelen 70 to further the streamline action.

My maximum transmition unit is already set at 1500 bytes by default. So I use the route utility to set my maximum segment size (defaulted at 536 bytes) and receive window to my internet gateway. I do this by using the following syntax with the route command.

route add default gw [gateway IP] dev [internet interface] window 65535 mss 1460

You can use route -ee to view your complete routing table information. I've also found a few internet server routing tweaks over at Linux.com, ask if interrested http://www.speedguide.net/ubb/biggrin.gif

I use all of those tweaks along with a few extra module options for my Vortex card to enable full duplex and set the amount of processes per interrupt.

I've only been using Linux for about 5 months now. I used to be one of those guys who spent hours on end researching advanced Microsoft Windows tunning. I always tried as hard as possible to get Windows to interreact fully with my hardware. After all, human code is the bottleneck in computers today, thats why we need to optimize it!!

I've found that in Windows you are limited at what you can do as far as optimization and performance is concerned. However, in Linux you have to ability to define every bit that passes through your hardware.

Stef

quickfoot
12-11-00, 04:22 PM
Thanks,

I believe if you define your windows at compile time rather than run time you can achieve a size greater than 64.

Mine are set to the windows 2000 patch size which is much greater than 64.

------------------
Microsoft Certified Systems Engineer

FreeBSD - The Power To Serve (http://www.freebsd.org)

[This message has been edited by quickfoot (edited 12-11-2000).]

Stef
12-11-00, 08:14 PM
Well, if you want an reveice window larger then 64KB your gonna have to recompile the linux kernel. The Linux TCP stack only uses 15bits of a TCP window field, I dont beleive that I have the solution to this, or that I could even compile my own kernel just yet http://www.speedguide.net/ubb/biggrin.gif