Bug 830881

Summary:	dracut udev is not creating block devices
Product:	[Fedora] Fedora	Reporter:	Russ <admin>
Component:	dracut	Assignee:	dracut-maint
Status:	CLOSED NOTABUG	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	17	CC:	dracut-maint, harald, jonathan
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-07-03 08:37:08 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Russ 2012-06-11 15:00:06 UTC

Description of problem:
the udev block devices are missing - preventing dracut from booting the system 

Version-Release number of selected component (if applicable):
dracut-*.fc17

How reproducible:
always

Steps to Reproduce:
1. create initramfs using dracut
2. reboot system using new initramfs

  
Actual results:
Using dracut 017-019 the system is unable to locate the root device and will not boot. It is unable to drop to a dracut shell for troubleshooting.

Using dracut-013-100.git20111021.fc17 the system is unable to locate the root device and drops to a dracut shell.


Expected results:
System boot as expected.

Additional info:
The dracut-013 shell shows no block devices were created by udev. Dmesg output shows that the kernel sees the storage devices. The block devices appear in the
sysfs.

Bug initially reported in https://bugzilla.redhat.com/show_bug.cgi?id=811003 and https://bugzilla.redhat.com/show_bug.cgi?id=827019.

Comment 1 Harald Hoyer 2012-06-12 13:15:32 UTC

does your kernel have CONFIG_DEVTMPFS ?

quick check:

$ mount |fgrep devtmpfs
devtmpfs on /dev type devtmpfs (rw,nosuid,size=1959264k,nr_inodes=489816,mode=755)

or try to mount it:

# mount -t devtmpfs -o mode=0755,nosuid,strictatime devtmpfs /dev

Comment 2 Russ 2012-06-12 19:50:12 UTC

(In reply to comment #1)
> does your kernel have CONFIG_DEVTMPFS ?
> 
No, it did not...

Thank you Harald. That solved the problem!

So it seems there was not really a bug regarding this issue, but that my kernel config was not compatible with the new dracut. I did not know about devtmpfs. It would have been helpful if there had been something posted somewhere on the need for it. Arch has something on their wiki about the need for it with custom kernels. But I did not find anything regarding the need for it in Fedora.

As I noted in https://bugzilla.redhat.com/show_bug.cgi?id=811003, I initially thought it could be a kernel configuration issue. So I tried making a new initramfs from the last F17 kernel:

dracut -v -H -f initramfs-3.3.7-1.fc17.x86_64-test.img 3.3.7-1.fc17.x86_64

That still resulted in the same udev issue. So then I assumed that it was not the kernel config.

This time, after your post, I tried using the kernel config from 3.4.0-1.fc17.x86_64. It worked this time. So it seems my issue is resolved.

Thank you for your patience, Harald.