Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.

RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Bug 960548

Summary:	RFE : "debug" for kernel cmdline
Product:	Red Hat Enterprise Linux 7	Reporter:	Petr Sklenar <psklenar>
Component:	systemd	Assignee:	systemd-maint
Status:	CLOSED CURRENTRELEASE	QA Contact:	Petr Sklenar <psklenar>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.0	CC:	jscotka, lnykryn, msekleta, systemd-maint-list
Target Milestone:	rc	Keywords:	FutureFeature
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	systemd-206-2.el7	Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-08-18 15:11:06 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:
Bug Depends On:
Bug Blocks:	816135

Description Petr Sklenar 2013-05-07 11:25:08 UTC

Description of problem:
RFE:

Steps to Reproduce:

Any chance of having a debug mode option already setup in
/etc/grub.d/10_linux (or wherever is appropriate) as it's tedious and
prone to user errors to:-

a) add systemd.log_level=debug systemd.log_target=kmsg log_buf_len=1M to
the kernel command line;

b) enable the debug-shell.service.

Also, enabling the debug-shell service activates tty9 which is not
accessible for a KVM right? Is there another option for KVMs?

Comment 3 Lukáš Nykrýn 2013-08-05 13:03:52 UTC

fixed in 206

Comment 5 Prarit Bhargava 2014-02-03 19:09:39 UTC

psklenar, this should be rejected in QA.  The problem is that you've now overridden the well known, well documented, and heavily used kernel boot parameter "debug" which has been in the kernel since 2.5.3.

As a result when debug is specified as a kernel parameter (which a lot of our internal scripts do) the result is a huge amount of debug code from systemd rendering kernel debugging via console useless.  There are *thousands* of lines of messages from systemd that cause important kernel debug messages to scroll of the console screen.

If people want a short systemd debug message, then implement systemd.debug or some such parameter.  Do not, however, overload the kernel's debug parameter.

Same goes for the "quiet" parameter FWIW.

P.

Comment 6 Petr Sklenar 2014-02-21 11:29:18 UTC

(In reply to Prarit Bhargava from comment #5)
<snip />
Ok, fails_qa as bugfix creates huge amount of debug code for heavily used kernel param 'debug'

Comment 7 Ludek Smid 2014-06-26 10:46:42 UTC

This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.

Comment 8 Ludek Smid 2014-06-26 11:15:31 UTC

The comment above is incorrect. The correct version is bellow.
I'm sorry for any inconvenience.
---------------------------------------------------------------

This request was NOT resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you need
to escalate this bug.