PXE boot crash

[Kenneth]

Hi,

I have a Windows 2008 with WDS installed, and trying to install CentOS 7 from there.

When I select CentOS 7, it just hangs with loading vmlinuz.

Settings:
LABEL CentOS 7.0
MENU LABEL CentOS 7.0
KERNEL Images/CentOS_7.0_x64/vmlinuz
APPEND initrd=Images/CentOS_7.0_x64/initrd.img ksdevice=eth0 ip=dhcp

It never tries to load initrd.img, so first step is to get vmlinuz load. It does not show any error messages or anything.

Anyone with some ideas to try out?

I have been trying vmlinuz from RHEL7, and that makes it continue to initrd.img from CentOS 7. But when this loads, it stops with this warning:
Warning: /dev/root does not exist

CentOS 6 booting fine from this setup.

I have been going through a lot of the topics, but none of them were able to help me out.

[aks]

So seemingly you boot (vmlinuz is started) but the initrd (to get the drivers etc. and to mount /) is not loaded? Yeah this kind of troubleshooting sucks (like a sucking thing on sucking day) as there's nothing to tell you what's going on.

Personally I'd take a packet dump from the PXE/TFTP server and/or hub out on the network path, then analyze with a good analyser (like Wireshark). Also logs on your TFTP server might help. Sorry I can't give more information (like type this magic command) as I'm not a windows person.

[Kenneth]

Thanks for you answer.

I don't think it starts loading initrd, I think it stops before. It doesn't show me the loading initrd.img message.

I will try your suggestion with Wireshark.

[Kenneth]

No luck with Wireshark. Seems to be downloading vmlinuz.

I have tried with vmlinuz from RHEL7, and this makes initrd.img from CentOS7 load. But it fails with there details:
dracut-initqueue[556]: Warning: Could not boot.
dracut-initqueue[556]: Warning: /dev/root does not exist

Any ideas?

[TrevorH]

This looks like https://bugs.centos.org/view.php?id=7341 where it seems the common factor in most case is the use of a Windows server as a tftp server.

[paulmuk]

I have a similar problem when trying to PXE install Centos 7 from a Linux TFTP server.

I've tried with and without a kickstart file, but each time the install fails at the dracut-initqueue step saying Could not boot, /dev/root does not exist.

I've downloaded the latest vmlinuz and initrd.img files to my TFTP server, and here are the relevant lines from my pxelinux.cfg/default file:

LABEL Centos-7.0-x86_64
MENU LABEL Install CentOS 7.0 x86_64
KERNEL images/centos/7.0/x86_64/vmlinuz
APPEND initrd=images/centos/7.0/x86_64/initrd.img ramdisk_size=100000 ksdevice=eth0 ip=dhcp url --url http://centos.serverspace.co.uk/centos/7/os/x86_64

It would appear that the vmlinuz and initrd files are loading fine, this failure occurs later in the boot process (I even get the Centos 7 progress bars if I switch terminals).

[TrevorH]

This is what I have that is working:

Code: Select all

LABEL CentOS 7 x86_64
        MENU LABEL CentOS 7.0 x86_64
        KERNEL images/centos/x86_64/7.0/vmlinuz
        APPEND initrd=images/centos/x86_64/7.0/initrd.img ramdisk_size=100000 ip=dhcp repo=http://192.168.1.7/mirrors/CentOS-7-x86_64/

[aks]

Yeah maybe do as Trevor suggests and use a repo that's in your LAN and not out on the Internet, who knows what happens out there!

[TrevorH]

I'm also not entirely sure that url --url works with CentOS 7...

[Kenneth]

Thanks for all of your answers!

Have been trying what TrevorH suggests, and which works for him.

It seems like a local mirror makes me come a bit further. It takes a lot longer time, seems like it's loading something. But the cursor is just blinking. And then after some time (~5 minutes), I get error you can see in the attachment.