Serial connection hangs when 2 DL140 starts at the same time

[Fourrier]

Hello,

I have to DL140 mirror servers, they are linked using a serial cable between them so I can take the control of the other using serial console over SSH (thru minicom -> Debian).

But when the two servers reboot at the same time, informations is transmited/received during BIOS boot time thru this cable making the startup hangs on both server...

The only solution is too delay the boot between servers...

This is not an OS problem since it occurs BEFORE the Bootloader ever appears (GRUB)

Is there an option I missed somewhere in my bios ??

Here is the bios remote access configuration (identical on both servers) :

Remote Access [Enabled]
Serial Port Mode [57600 8,n,1]
Flow Control [Hardware]
Redirection After BIOS POST [Boot Loader]
Terminal Type [VT100]
VT-UTF8 Combo Key Support [Disabled]

The Bios in the latest on date : Nov 2004

i did not used the max speed (115200) because it makes GRUB hangs... (weird but that's another problem)

Thanks for your help