[SOLVED] Stop first 20 boot messages clearing

Colanco · 2013-08-10 21:33:32

How to stop the first 20 or so, boot messages clearing? Petty sure this happened after a previous systemd update.
I know about changing TTYVTDisallocate to no - https://wiki.archlinux.org/index.php/Sy … er_boot.3F - but this only keeps the remaining messages on screen.

Last edited by Colanco (2013-08-12 07:58:49)

redstar · 2013-08-10 21:39:36

Similar, but perhaps this will work: https://wiki.archlinux.org/index.php/Di … ot_Message

karol · 2013-08-10 22:01:58

Can't you scroll back with Shift + PgUp?

Colanco · 2013-08-10 22:33:54

No, cannot scroll up at all. All boot messages are shown on boot, but soon disappear leaving only the last few showing.

cfr · 2013-08-10 22:38:10

karol wrote:

Can't you scroll back with Shift + PgUp?

Does that really work for you? I always assumed it was normal for it not to work for the boot messages.

karol · 2013-08-10 22:39:38

Just to be sure (because I can scroll them up): press and hold Shift and press PgUp.

cfr · 2013-08-11 01:36:35

Hmm... Wonder why it doesn't work for me. That is, it works in VTs otherwise but it never works for the boot messages.

karol · 2013-08-11 01:47:32

I've tested it on nvidia-equipped computer i.e. no KMS (I'll test it on Intel with KMS later).
By boot messages I mean my syslinux menu and systemd messages.

cfr · 2013-08-11 02:10:53

I meant the systemd messages after I've booted the kernel from grub which is loaded by rEFInd. Just because the grub menu disappears I think so I don't expect to find that. But I can only see the last screenful of systemd messages on the CLI. Everything else scrolls away irreversibly (that I've found).

This is intel with early kms.

I wonder if it it because I boot into X - even though X starts on a different VT.

Last edited by cfr (2013-08-11 02:11:08)

Colanco · 2013-08-11 10:20:05

OK, with kms disabled in syslinux.cfg with the nomodeset kernel parameter, all boot messages are shown and available with scroll up (Shift + PageUp)

It would seem when kms kicks in, boot messages that went before are cleared (scroll buffer cleared?) and thus not available to be shown.

My setup is ATI drivers with the default late start KMS.

Last edited by Colanco (2013-08-11 10:21:05)

karol · 2013-08-11 15:33:32

https://bugs.archlinux.org/task/32207
(see last comment)

falconindy wrote:

if you use a driver like i915 (one that uses KMS), then your console is reset when the module is loaded.

I can scroll back with KMS enabled to the line which was topmost when the consolefont changed.

It may also be the case of https://wiki.archlinux.org/index.php/Scrollback_buffer

Edit: Enlarging the scrollback buffer still doesn't let me scroll past before KMS kicked in.

If systemd has an option to set the boot messages verbosity, it can help too.

Last edited by karol (2013-08-11 15:44:54)

cfr · 2013-08-11 15:52:44

Hmm... I'm using early KMS so I'm not sure if that applies in my case or not...

Colanco · 2013-08-12 07:57:50

Solved this on my particular setup by doing the following:

1. Enabled 'early KMS start' by adding radeon to MODULES line in /etc/mkinitcpio.conf:
https://wiki.archlinux.org/index.php/KM … _KMS_start

This was needed to stop console is being reset by the graphics module in Late KMS Start (default) thus clearing boot messages before module was loaded.

2. Change TTYVTDisallocate to no in getty@tty1.service to stop boot message clearing:
https://wiki.archlinux.org/index.php/Di … t_Messages

3. Increased scrollback for console by adding fbcon=scrollback:300k to /boot/syslinux/syslinux.cfg.
https://wiki.archlinux.org/index.php/Scrollback_buffer

This allows all boot messages to be accessed straight after boot via Shift + PageUp. No clearing of screen is performed.

Also a (bug?) with the default Late Start KMS means the console font in vconsole.conf is ignored. With the Early KMS start method, the font is used correctly, so consequently the console font is now different than before. I changed the font to match the default (non-used) font:

KEYMAP=uk
FONT=ter-216b

terminus-font can be found in Community.

Last edited by Colanco (2013-08-12 08:14:46)

karol · 2013-08-12 11:52:51

https://bugs.archlinux.org/task/32207 ?

cfr · 2013-08-12 23:33:21

Colanco wrote:

Solved this on my particular setup by doing the following:

Thanks for posting this - really appreciate it.

1. Enabled 'early KMS start' by adding radeon to MODULES line in /etc/mkinitcpio.conf:
https://wiki.archlinux.org/index.php/KM … _KMS_start
This was needed to stop console is being reset by the graphics module in Late KMS Start (default) thus clearing boot messages before module was loaded.

OK. So I guess early KMS is not my problem .

2. Change TTYVTDisallocate to no in getty@tty1.service to stop boot message clearing:
https://wiki.archlinux.org/index.php/Di … t_Messages

This does not seem like the right way to do this but I'm not entirely sure what is. I think that what is in that directory should be just a symlink.

The recommended way to edit unit files is at https://wiki.archlinux.org/index.php/Sy … unit_files. However, I'm not clear quite how to apply that in this case. What I'm currently trying is

$ cat /etc/systemd/system/getty@.service.d/TTYVTDisallocate-BLOCK.conf 
[Service]
TTYVTDisallocate=no

However this will affect all VTs generated from the template. Does anybody know if it is bad to have TTYVTDisallocate set to false for tty{2,3,...}?

EDIT: Or are the other VTs generated from something else? It makes no sense to me they'd be generated from the template in /usr/lib/systemd/system since surely TTYVTDisallocate is inappropriate for the other ttys? Doesn't disallocating it make it unavailable for login etc.? Or have I misunderstood?

3. Increased scrollback for console by adding fbcon=scrollback:300k to /boot/syslinux/syslinux.cfg.
https://wiki.archlinux.org/index.php/Scrollback_buffer

Did you also append xxxfb as the wiki says? If so, what did you use? I'm confused because it mentions the name of your video driver but I'm not sure what that is since this is not concerned with X.

Last edited by cfr (2013-08-12 23:35:57)

karol · 2013-08-12 23:37:20

cfr wrote:

Did you also append xxxfb as the wiki says? If so, what did you use? I'm confused because it mentions the name of your video driver but I'm not sure what that is since this is not concerned with X.

If you want to know what name to use, try

$ cat /proc/fb

cfr · 2013-08-12 23:42:18

Ah, thanks karol. I guess if I need to append it, that'd be inteldrmfb in my case. I wonder if it is necessary, though? I am pretty sure that gets used by default anyway as now I've seen it listed there, I realise it gets mentioned a lot in the boot logs. That is, I didn't connect it with the wiki page because I didn't really realise what it was but now I know that's it, I do know I'm already using it without specifying it at all.

karol · 2013-08-12 23:56:57

Yup, seems to work w/o inteldrmfb on the APPEND line. Do you think the wiki should be edited?

cfr · 2013-08-13 00:09:26

karol wrote:

Yup, seems to work w/o inteldrmfb on the APPEND line. Do you think the wiki should be edited?

I'm not sure since the wiki is general - is it not necessary at all? Not necessary for intel cards? Not necessary for intel cards using early KMS?

karol · 2013-08-13 00:16:41

cfr wrote:

I'm not sure since the wiki is general - is it not necessary at all? Not necessary for intel cards? Not necessary for intel cards using early KMS?

Good question ;P (yeah, I used your words as mine, I'm a bad bad person)

I don't want to run OT with this, so I suggest a new thread or the wiki talk page.

cfr · 2013-08-13 21:21:48

Hmm... This solution doesn't work for me. I can scroll on tty1 but there is so little to scroll it is hardly worth it.

Just to check I didn't miss anything:

$ cat /etc/systemd/system/getty\@.service.d/TTYVTDisallocate-BLOCK.conf 
[Service]
TTYVTDisallocate=no

I would assume this was the problem except it clearly is effective: tty1 is available for log in and shift + pgup works - there just isn't much to scroll.

Using early kms (i915 is in the MODULES array of mkinitcpio.conf).

Added

fbcon=scrollback:200k

to kernel command line and confirmed it is actually used in /proc/cmdline. Although the OP specified 300k, I'm assuming 200k should get me more scrollback than the approximately 2 lines I get preserved right now. Moreover, now that I go back to tty1 to check, I can't scroll back at all. Do I need to log in on tty1?

karol · 2013-08-13 21:32:42

If you have 'quiet' on the APPEND line there won't be much output.
KMS means native resolution, which in turn means small font, so most of the messages may be visible to you anyway.

Have you tried interrupting boot with Ctrl-S? https://bbs.archlinux.org/viewtopic.php … 1#p1282511

cfr · 2013-08-16 23:55:00

I don't have 'quiet' and I see many messages scroll by. I just can't access them after boot.

Because this didn't work, I actually tried to switch back to the default getty@1 service (i.e. including the disallocation) but for some reason, I am now getting messages completely cleared when boot is complete and tty1 is not disallocated. So now I'm really confused.

I haven't tried the ctrl+s thing but I'll try to remember to try next time I boot. (Just rebooted for glibc again so won't try this immediately.)

Last edited by cfr (2013-08-16 23:55:22)

karol · 2013-08-17 00:23:26

cfr wrote:

I haven't tried the ctrl+s thing

I did - works for me.
Use Ctrl+Q to unpause.

estan · 2015-04-29 09:54:10

I know this is marked as SOLVED, but I would just like to ask: Has anyone with intel graphics gotten this to work without disabling KMS completely (like Colanco did)? I would like to use KMS modesetting but still be able to scroll.

What I did:

1. Enable early boot KMS:

[estan@pyret ~]$ egrep "^MODULES" /etc/mkinitcpio.conf 
MODULES="i915"

2. Disabled clearing of messages:

[estan@pyret ~]$ cat /etc/systemd/system/getty\@tty1.service.d/noclear.conf 
[Service]
TTYVTDisallocate=no

3. Increased the scrollback buffer:

[estan@pyret ~]$ egrep "^GRUB_CMDLINE_LINUX_DEFAULT" /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="fbcon=scrollback:512k"
[estan@pyret ~]$

But still I cannot scroll using Shift+PgUp on tty1.

Any ideas?

UPDATE: And just to be clear. I'm not using the quiet kernel parameter, so I am seeing the startup messages ("[ OK ] ..." et.c.) go past during boot. But I end up with just the last half page of them, without being able to scroll

Last edited by estan (2015-04-29 09:56:06)

Arch Linux

#1 2013-08-10 21:33:32

[SOLVED] Stop first 20 boot messages clearing

#2 2013-08-10 21:39:36

Re: [SOLVED] Stop first 20 boot messages clearing

#3 2013-08-10 22:01:58

Re: [SOLVED] Stop first 20 boot messages clearing

#4 2013-08-10 22:33:54

Re: [SOLVED] Stop first 20 boot messages clearing

#5 2013-08-10 22:38:10

Re: [SOLVED] Stop first 20 boot messages clearing

#6 2013-08-10 22:39:38

Re: [SOLVED] Stop first 20 boot messages clearing

#7 2013-08-11 01:36:35

Re: [SOLVED] Stop first 20 boot messages clearing

#8 2013-08-11 01:47:32

Re: [SOLVED] Stop first 20 boot messages clearing

#9 2013-08-11 02:10:53

Re: [SOLVED] Stop first 20 boot messages clearing

#10 2013-08-11 10:20:05

Re: [SOLVED] Stop first 20 boot messages clearing

#11 2013-08-11 15:33:32

Re: [SOLVED] Stop first 20 boot messages clearing

#12 2013-08-11 15:52:44

Re: [SOLVED] Stop first 20 boot messages clearing

#13 2013-08-12 07:57:50

Re: [SOLVED] Stop first 20 boot messages clearing

#14 2013-08-12 11:52:51

Re: [SOLVED] Stop first 20 boot messages clearing

#15 2013-08-12 23:33:21

Re: [SOLVED] Stop first 20 boot messages clearing

#16 2013-08-12 23:37:20

Re: [SOLVED] Stop first 20 boot messages clearing

#17 2013-08-12 23:42:18

Re: [SOLVED] Stop first 20 boot messages clearing

#18 2013-08-12 23:56:57

Re: [SOLVED] Stop first 20 boot messages clearing

#19 2013-08-13 00:09:26

Re: [SOLVED] Stop first 20 boot messages clearing

#20 2013-08-13 00:16:41

Re: [SOLVED] Stop first 20 boot messages clearing

#21 2013-08-13 21:21:48

Re: [SOLVED] Stop first 20 boot messages clearing

#22 2013-08-13 21:32:42

Re: [SOLVED] Stop first 20 boot messages clearing

#23 2013-08-16 23:55:00

Re: [SOLVED] Stop first 20 boot messages clearing

#24 2013-08-17 00:23:26

Re: [SOLVED] Stop first 20 boot messages clearing

#25 2015-04-29 09:54:10

Re: [SOLVED] Stop first 20 boot messages clearing

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