[CentOS] Disable window scaling during kickstart

[Plant, Dean]

Ray Van Dolson wrote:
> On Thu, May 10, 2007 at 06:34:54PM +0100, Plant, Dean wrote:
>> Hello List,
>> 
>> Due to a problem with CentOS 5 and one of our firewalls I am having
>> to disable tcp window scaling to stop network connections grinding
>> to a halt. I am also trying to Kickstart CentOS 5 machines through
>> the firewall so need to disable window scaling at install time.
>> 
>> I have added to the kickstart file
>> 
>> %pre
>> echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
>> 
>> But the install still hangs while transferring the stage2.img
>> 
>> Should the above %pre work or do I need to do something else to
>> disable window scaling during the install.
>> 
>> In case anyone's interested CentOS 5 is the first time we have
>> suffered this problem both CentOS 3&4 worked without issue.
> 
> Weird issue.  Haven't seen anyone else have it (at least on this
> list). 
> 
> Can you switch over to your shell console when the hang happens and
> examine the value of tcp_window_scaling to see if maybe it gets reset
> somehow?  I believe %pre should work....
> 

Weird... Tell me about it, I spent a lot of time head scratching trying
to figure out why network connections would just mysteriously hang.
Eventually found reference to a problem with tcp_window_scaling and
firewalls and after disabling tcp_window_scaling on my test CentOS 5
box, everything started working.

The install does not get far enough for the shell console to be
available, it hangs at the transferring stage2.img.

Dean