Bug 676923

Summary: no /dev/rtc until after udev starts
Product: Red Hat Enterprise MRG Reporter: Guy Streeter <streeter>
Component: realtime-kernelAssignee: John Kacur <jkacur>
Status: CLOSED CURRENTRELEASE QA Contact: David Sommerseth <davids>
Severity: medium Docs Contact:
Priority: high    
Version: 1.3CC: bhu, jkacur, juergen.schilp, lgoncalv, nobody, ovasik
Target Milestone: ---Keywords: Reopened
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2012-02-08 19:01:53 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Flags
console log showing the error none

Description Guy Streeter 2011-02-11 21:08:07 UTC 
There was a patch in the 2.6.24 RT kernel to create a /dev/rtc device so that the hwclock command would work during system startup. It appears to be missing from the 2.6.33 kernel.
Without the patch, this error occurs:

		Welcome to Red Hat Enterprise Linux Client
		Press 'I' to enter interactive startup.
Cannot access the Hardware Clock via any known method.
Use the --debug option to see the details of our search for an access method.

After the system boots and the udev rule created the link from /dev/rtc0 to /dev/rtc, the hwclock command works correctly.
Comment 1 Guy Streeter 2011-02-11 21:33:05 UTC 
Created attachment 478318 [details]
console log showing the error
Comment 3 David Sommerseth 2011-03-03 14:51:10 UTC 
Verified by code review and checking boot log.

Found bz465837-rtc-compat-rhel5.patch-ported-to-V2.patch applied to the kernel-rt-2.6.33.7-rt29.53.src.rpm.

When booting kernel-rt-2.6.33.7-rt29.47, this message is shown during the boot process:
-----------------------------------------------------------------
Cannot access the Hardware Clock via any known method.
Use the --debug option to see the details of our search for an access method.
-----------------------------------------------------------------

This error is not happening when booting kernel-rt-2.6.33.7-rt29.53.