We have an embedded system running 2.4, we need to quickly (within 5 secs) stop all disk access and go into single user mode to run the fail safe app.
The problem is that killing all processes will take too long before doing umounts. But it seems that doing a 'init 1' will quickly suspend all process without killing them which is fast (true?) But I can't umount so I'm afraid that the drive would still be accessed.
Is there someway to suspend drive access, like shutting down the ide driver?
I'm sure you will probably be asking why, so here's a brief
Our system needs to run certain applications when the hard drive fails. We know the hd will fail under certain tempertures, so when we hit that temperture, we need to stop drive access and run apps from CF. If the hd is accessed during this time, the system locks (probably because of seek errors, or ide driver failing - we don't know). So we need to prevent hd access during the failed temp ranges.