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Bug 960548 - RFE : "debug" for kernel cmdline
Summary: RFE : "debug" for kernel cmdline
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: systemd
Version: 7.0
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: ---
Assignee: systemd-maint
QA Contact: Petr Sklenar
URL:
Whiteboard:
Depends On:
Blocks: 816135
TreeView+ depends on / blocked
 
Reported: 2013-05-07 11:25 UTC by Petr Sklenar
Modified: 2014-08-18 15:11 UTC (History)
4 users (show)

Fixed In Version: systemd-206-2.el7
Doc Type: Enhancement
Doc Text:
Clone Of:
Environment:
Last Closed: 2014-08-18 15:11:06 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)

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.

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