cc: cloud@, server@ fpo
Hi,
When troubleshooting early boot issues with a console, e.g. virsh console, or the virt-manager console, or even a server's remote management console providing a kind of virtual serial console... the boot scroll is completely wiped. This is a new behavior in the last, I'm not sure, 6-12 months? Everything before about 3 seconds is cleared as if the console reset command was used, as in it wipes my local scrollback.
I captured this with the script command, and when I cat this 76K file, it even wipes the local console again. So there is some kind of control character that's ordering my local console to do this. The file itself contains the full kernel messages. I just can't cat it. I have to open it in a text editor that ignores this embedded console reset command.
With the help of @glb, we discovered that this is almost certainly Plymouth. When I boot with parameter plymouth.enable=0 the problem doesn't happen. And hence the higher level question if we really even need Plymouth in Server or Cloud editions?
I suppose ideally we'd track down the problem and fix plymouth, so that existing installations get fixed. Whereas if we remove plymouth, we have to ponder whether and how to remove plymouth from existing installations. Unless we flat out aren't using it at all.
Any ideas?
Plymouth is in the @core group in fedora-comps, so pretty much everything gets it. https://pagure.io/fedora-comps/blob/main/f/comps-f37.xml.in#_635
-- Chris Murphy
On Tue, Aug 9, 2022 at 11:10 AM Chris Murphy lists@colorremedies.com wrote:
cc: cloud@, server@ fpo
Hi,
When troubleshooting early boot issues with a console, e.g. virsh console, or the virt-manager console, or even a server's remote management console providing a kind of virtual serial console... the boot scroll is completely wiped. This is a new behavior in the last, I'm not sure, 6-12 months? Everything before about 3 seconds is cleared as if the console reset command was used, as in it wipes my local scrollback.
I captured this with the script command, and when I cat this 76K file, it even wipes the local console again. So there is some kind of control character that's ordering my local console to do this. The file itself contains the full kernel messages. I just can't cat it. I have to open it in a text editor that ignores this embedded console reset command.
With the help of @glb, we discovered that this is almost certainly Plymouth. When I boot with parameter plymouth.enable=0 the problem doesn't happen. And hence the higher level question if we really even need Plymouth in Server or Cloud editions?
I suppose ideally we'd track down the problem and fix plymouth, so that existing installations get fixed. Whereas if we remove plymouth, we have to ponder whether and how to remove plymouth from existing installations. Unless we flat out aren't using it at all.
Any ideas?
Plymouth is in the @core group in fedora-comps, so pretty much everything gets it. https://pagure.io/fedora-comps/blob/main/f/comps-f37.xml.in#_635
Plymouth is used to provide the interface for decrypting disks and presenting information about software/firmware updates, so I'd be loath to remove it.
That said, it should all be captured in systemd journal logs though.
On Tue, Aug 9, 2022, at 11:29 AM, Neal Gompa wrote:
Plymouth is used to provide the interface for decrypting disks and presenting information about software/firmware updates, so I'd be loath to remove it.
On desktops yes, but I think we can modify systemd-ask-password-plymouth.service so that it omits --plymouth from systemd-tty-ask-password-agent?
On Tue, 2022-08-09 at 11:29 -0400, Neal Gompa wrote:
Plymouth is used to provide the interface for decrypting disks and presenting information about software/firmware updates, so I'd be loath to remove it.
IIRC we found that this prompting does actually still work if plymouth isn't installed, but the prompt can get kinda buried in a flood of other text.
On Tue, 2022-08-09 at 11:09 -0400, Chris Murphy wrote:
cc: cloud@, server@ fpo
Hi,
When troubleshooting early boot issues with a console, e.g. virsh console, or the virt-manager console, or even a server's remote management console providing a kind of virtual serial console... the boot scroll is completely wiped. This is a new behavior in the last, I'm not sure, 6-12 months? Everything before about 3 seconds is cleared as if the console reset command was used, as in it wipes my local scrollback.
I captured this with the script command, and when I cat this 76K file, it even wipes the local console again. So there is some kind of control character that's ordering my local console to do this. The file itself contains the full kernel messages. I just can't cat it. I have to open it in a text editor that ignores this embedded console reset command.
With the help of @glb, we discovered that this is almost certainly Plymouth. When I boot with parameter plymouth.enable=0 the problem doesn't happen. And hence the higher level question if we really even need Plymouth in Server or Cloud editions?
I suppose ideally we'd track down the problem and fix plymouth, so that existing installations get fixed. Whereas if we remove plymouth, we have to ponder whether and how to remove plymouth from existing installations. Unless we flat out aren't using it at all.
Any ideas?
Plymouth is in the @core group in fedora-comps, so pretty much everything gets it. https://pagure.io/fedora-comps/blob/main/f/comps-f37.xml.in#_635
We actually took it out briefly not so long ago, but put it back mostly because of this bug: https://bugzilla.redhat.com/show_bug.cgi?id=1940163 AFAIK that bug is still around, at least nobody has claimed it's fixed.
See https://pagure.io/fedora-comps/pull-request/642 and https://bugzilla.redhat.com/show_bug.cgi?id=1933378 for more context.
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Adam Williamson -
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Neal Gompa