Most recent kernel where this bug did not occur: Not before (new machine, can only install Linux Version higher than 2.6.18) Distribution: Fedora Core 7 (F-7-x86_64-DVD.iso, download from FC official website) Hardware Environment: CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 5000+ Mother board: ASUS M2N6 (Video card, Sound card and Attansic L1 Gigabyte network interface integreted) Hard Drive: 160G SATA Memory: 4 GB Monitor, keyboard and mouse: through KVM Software Environment: System default. Services: ssh, ftp (firewall and SElinux are disabled) Problem Description and Steps to reproduce: 1. At first, I installed a test version of RH AS5 (kernel 2.6.18). The kernel did not contain the driver of the network interface (Attansic L1), so I installed a third-party driver. However, the system frequently halted under such conditions: (1). Memory usage exceed 3.5GB (by command 'top'); (2). kill running mpi jobs (i.e. killall vasp); (3). upload large files (larger than 1GB) when a ssh (putty) window or a VNC window is open. (4). for sometimes, no any interfere, died itself. Mention that once the system halted (without any error information), there will be no any response unless I press the reset button. So I shifted to Fedora Core 7 after 1 month's pain... but problem is still there. 2. Error triger: (1). uploading large files (an iso file, larger than 1GB). The system will freeze randomly during the transfer period; (2) If fortunately, I can finish up the transfer, I mount the iso file and them excute a install script, the system freezes. Both these two trigers will let a Putty window give error messages like: [blade@fc05 test]$ Message from syslogd@ at Tue Oct 2 23:31:06 2007 ... fc05 kernel: Oops: 0000 [1] SMP Message from syslogd@ at Tue Oct 2 23:31:06 2007 ... fc05 kernel: CR2: fffffffffab23e78 Message from syslogd@ at Tue Oct 2 23:33:00 2007 ... fc05 kernel: general protection fault: 0000 [2] SMP ------------------- I am not sure if this is a kernel bug BUT I cannot find anywhere for help. I hope somebody can give me advices.