Hi, I am getting the following error message as part of stack trace. I have a system with > 4G mem with RHEL4 x86_64. I installed the OS and when I did the reboot, the system failed with a stack trace with errors as follows: Intializing hardware..... kernel BUG at pageattr:107 Invalid operand:0000 [1] SMP Modules linked in: hw_random tg3 floppy sd_mod aic79xx(U) scsi_mod dm_snapshot dm_zero dm_mirror ext3 jbd dm_mod pid: 1217,comm:modprobe.... .............. ................ ............... RIP ...{__change_page_attr+1039} /etc/rc.d/rc.sysinit: line 167: 1217 Segmentation fault modprobe $1 >/dev/null 2>&1 I wanted to know if aic79xx driver is having some problems or is it kernel/scsi subsystem. I don't see the stack trace pointing to aic79xx driver at all. Also, the above issue is only for > 4G mem. Thanks in advance for the help. with regards, Anil - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html