Other people have answered the meat of the question. Some additional commentary:
On Thu, 18 Apr 2002, at 8:01am, Rodent of Unusual Size wrote: > I basically want to be able to give an irresistable three finger salute > through the serial port if need be, to *force* a crash/reboot. If the system is well and truly hung, the Linux serial console may be toast, too, and will not help you. You may need to look into hardware or semi-hardware solutions. Many "server" machines have BIOS options which can enable pre-boot serial support, and even let you do things like force a hardware reset. If your "server" is not one of those, there are after-market cards which provide similar functionality. > 2. Provided I can get in, is there any way I can *crash* the > system so I can take a look at a dump to figure out WIH was > going on to wedge it? There is a kernel debugger available that may do what you want. It is a source patch to the kernel. On 18 Apr 2002, at 8:29am, Cole Tuininga wrote: > You have to have serial support turned on on the server obviously, do not > turn on "support for console on serial port". Believe it or not, this is > not what you want. I disagree, here; seeing the kernel boot messages can be very useful, and having the support enabled but not used certainly won't hurt. One thing I have used this for is capturing a kernel panic that was occurring before init was spawned -- kernel serial console attached to another computer, and logging in Minicom. Sure beats transcribing a stack dump by hand! On Thu, 18 Apr 2002, at 9:01am, Ben Boulanger wrote: > ... but I wonder if that kernel config option "SysRq key" would help you > here. Yah, you send a serial break signal, followed by one of the Magic keys. Sending BREAK followed by 'b' (for boot) might be useful, if the serial driver is not hung. -- Ben Scott <[EMAIL PROTECTED]> | The opinions expressed in this message are those of the author and do not | | necessarily represent the views or policy of any other person, entity or | | organization. All information is provided without warranty of any kind. | ***************************************************************** To unsubscribe from this list, send mail to [EMAIL PROTECTED] with the text 'unsubscribe gnhlug' in the message body. *****************************************************************
