CoreOS 835 PXE boot hang after device-mapper at Cisco UCS C200 M2

[叶朝敏]

Hi there,

I'm now trying CoreOS with PXE (via Cobbler and PXELinux actually) on a Cisco UCS C200 M2, however, CoreOS seems to hang at PXE booting, as can be seen from the screen capture below: (I don't know how to capture the text from the UCS's KVM window, if you know please tell me, sorry for this :().

This issue happens occasionally, sometimes it can boot successfully, and the device is able to got the cloud-config from the URL I specified on the kernel line, some times it failed without any reason. Since it failed to boot I cannot continue to get system boot log via journalctl or so. 

Here's my PXELinux configuration for CoreOS:

在此输入代码...

default linux

prompt 0

timeout 1

label linux

        kernel /images/coreos-stable-835/vmlinuz

        ipappend 2

        append initrd=/images/coreos-stable-835/cpio.gz rootflags=loop root=/coreos_stable_835.iso coreos.autologin console=tty0 console=ttyS0 rootfstype=tmpfs udev.event-timeout=60 cloud-config-url=http://192.168.1.10/cloud-configs/cloud-config-e0:2f:6d:bc:08:bc.yml

[叶朝敏]

I googled a lot but were not lucky enough to find similar problems. Anyone ran into same issue? Or if you have any clue to troubleshoot this, I'd appreciate your kind help. Thanks in advance!

在 2016年4月18日星期一 UTC+8下午5:48:35，叶朝敏写道：

[lukasz....@intel.com]

In https://github.com/coreos/bugs/issues/152 you might be able to find workaround.

[Brandon Philips]

There is a documentation problem that we need to fix: https://github.com/coreos/docs/issues/793

You shouldn't be specifying the "iso" stuff in root= for example.

[Philip Ye]

Thanks lukasz, seems that that issue happens when running coreos-install, while my issue occur during PXE boot, *before* coreos-install actually.  

[Philip Ye]

Thanks Michael, let me give it a try.

[Philip Ye]

Thank you Michael, removing these two options for root, i.e. rootflags=loop root=/coreos_stable_835.iso, CoreOS can successfully PXE now. 

[V Benincosa]

Didn't use Cobbler but using regular IPXE I updated a guide for UCS and CoreOS.  I tested on UCS M2, M3, & M4.  Seemed to work great.  

https://ciscoucs.github.io/os/2017/04/06/coreos