I've just installed CentOS 4.2 on a brand-new PC. It appears to be working fine except for one thing: When the system is first powered on, the boot sequence hangs after Starting udev: Initializing hardware ... storage network audio If I then hit the reset button, it reboots and successfully proceeds. Looking at rc.sysinit and the output of kmodule, it would appear that the problem is with loading the pciehp module. In dmesg after the successful boot I can see a bunch of errors from that module (cut'n'paste appended at the end of this message), but everything appears to be working correctly -- graphical boot was fine, gdm starts up and I have a functional X session when I log in. Any clues? Google found some Debian bug reports regarding hotplug and USB drives ... hmm, now that I think of it, I do have a USB mouse plugged in at boot time, next chance I have I'll try it without that. Adding "redhat" or "centos" to the search didn't turn up anything conclusive. Other details: System installed from CentOS 4.0 ISOs, then upgraded to 4.2 with yum Motherboard is ASUS P5N32-SLI, using onboard sound Radeon X300SE PCI-E graphics card Power-on boot from the install CD also hung, at "running /sbin/loader" but rebooted correctly into the installer after the reset button was pressed. Error dump from dmesg: Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist Evaluate _OSC Set fails. Status = 0x0005 ACPI-1133: *** Error: Method execution failed [\_SB_.LSTA] (Node f7f5ff00), AE_AML_OPERAND_TYPE ACPI-1133: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE ACPI-0158: *** Error: Method execution failed [\_SB_.LATA._STA] (Node f7f001e0), AE_AML_OPERAND_TYPE pciehp: Both _OSC and OSHP methods do not exist