| View previous topic :: View next topic |
| Author |
Message |
hrnick
Guru
Joined: 31 Aug 2002
Posts: 425
Location: Sweden
|
 Posted: Mon Feb 05, 2024 11:52 am Post subject: How do I know initramfs is working? |
 |
|
I have tried to set up initramfs according to the Gentoo Wiki using genkernel after reading that Separate /usr now requires an initramfs. From what I understand any workarounds will no longer be supported and will be decommissioned, starting today. The question is; how do I know that I have set up initramfs correctly and that it's working?
There is something related to initramfs in /boot...
| Code: | $ find /boot/ -iname *initr*
/boot/initramfs-6.6.10-gentoo-x86_64.img.old
/boot/initramfs-6.7.1-gentoo-r1-x86_64.img |
...and something is being unpacked when booting...
| Code: | $ dmesg | grep initr
[ 0.436268] Unpacking initramfs...
[ 1.149086] Freeing initrd memory: 9192K |
Is this enough to feel comfortable that my system will be able to boot once all the workarounds have been decommissioned or is there any other way of telling? Any help would be appreciated! |
|
| Back to top |
|
 |
NeddySeagoon
Administrator
Joined: 05 Jul 2003
Posts: 54263
Location: 56N 3W
|
| Posted: Mon Feb 05, 2024 1:18 pm Post subject: |
|
|
hrnick,
In theory, an initrd will only be required on systems that have /usr on a separate filesystem to / (root)
Until the separate /usr workarounds have been removed. there is no way to test.
My setup does not currently need an initrd and I have both /usr and /var on their own logical volumes.
I've made and tested an initrd and I shall be testing weekly to see if its required or not.
I also do lots of other not recommend things, partly because I can and partly because I don't like automation I don't understand.
The intent is that both root and /usr must be available before localmount runs as bits of /usr will be required before then.
-- edit --
I suppose you could edit the localmount script to run when it starts and finishes.
That will only show that the initrd met the intent of the change.
_________________
Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
|
| Back to top |
|
|
hrnick
Guru
Joined: 31 Aug 2002
Posts: 425
Location: Sweden
|
| Posted: Mon Feb 05, 2024 8:40 pm Post subject: |
|
|
| NeddySeagoon wrote: | | In theory, an initrd will only be required on systems that have /usr on a separate filesystem to / (root) |
This is the setup I have, that's why I have been eager to set this up correctly...
| Quote: | Until the separate /usr workarounds have been removed. there is no way to test.
My setup does not currently need an initrd and I have both /usr and /var on their own logical volumes. |
So there will be exciting times ahead then, I'll make sure to have my bootable Gentoo USB stick ready. 
| Quote: | I suppose you could edit the localmount script to run when it starts and finishes.
That will only show that the initrd met the intent of the change. |
So both / and /usr are mounted before mount -at is run by /etc/init.d/localmount, I guess that's the sign I am looking for then? |
|
| Back to top |
|
|
NeddySeagoon
Administrator
Joined: 05 Jul 2003
Posts: 54263
Location: 56N 3W
|
| Posted: Mon Feb 05, 2024 9:05 pm Post subject: |
|
|
hrnick,
Yes, correct. That's as good as it gets today.
Now we can wait for the breakage. :)
_________________
Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
|
| Back to top |
|
|
hrnick
Guru
Joined: 31 Aug 2002
Posts: 425
Location: Sweden
|
| Posted: Mon Feb 05, 2024 9:08 pm Post subject: |
|
|
| Thanks for your help! I'll start making popcorn and keep that USB stick ready. |
|
| Back to top |
|
|
GDH-gentoo
Veteran
Joined: 20 Jul 2019
Posts: 1541
Location: South America
|
| Posted: Mon Feb 05, 2024 9:16 pm Post subject: |
|
|
| NeddySeagoon wrote: | | My setup does not currently need an initrd and I have both /usr and /var on their own logical volumes. |
Same. The rootfs is an ext4 partition, the kernel has all needed support for mounting it built-in, /usr is an LVM logical volume, everything needed by OpenRC (and an s6-based init system) before filesystems in /etc/fstab are mounted lives in /bin, /lib64 and /sbin, including vgchange, so all is good.
Well, except for (the soon to become EWONTFIX, I suppose) bug 902829, which forces me to make a copy of libcrypto in /lib64 each time I see dev-libs/openssl scheduled for update, but that's life I guess 
| hrnick wrote: | | So both / and /usr are mounted before mount -at is run by /etc/init.d/localmount, I guess that's the sign I am looking for then? |
/usr would be mounted before even OpenRC starts running, yeah. I don't know how an initramfs created by dracut or Genkernel manages running the udev daemon in a way that doesn't conflict with the service manager later, though.
Also, OpenRC's localmount creates a /run/openrc/usr_premounted file if it finds that /usr is already mounted, you can check that for a clue.
_________________
| NeddySeagoon wrote: | | I'm not a witch, I'm a retired electronics engineer |
| Ionen wrote: | | As a packager I just don't want things to get messier with weird build systems and multiple toolchains requirements though |
Last edited by GDH-gentoo on Mon Feb 05, 2024 9:57 pm; edited 1 time in total |
|
| Back to top |
|
|
NeddySeagoon
Administrator
Joined: 05 Jul 2003
Posts: 54263
Location: 56N 3W
|
| Posted: Mon Feb 05, 2024 9:26 pm Post subject: |
|
|
GDH-gentoo,
| Quote: | | Also, OpenRC's localmount creates a /run/openrc/usr_premounted ... |
Openrc used to shout at me about /usr already mounted until I set it noauto in fstab..
I noticed that was missing.
_________________
Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
|
| Back to top |
|
|
GDH-gentoo
Veteran
Joined: 20 Jul 2019
Posts: 1541
Location: South America
|
| Posted: Mon Feb 05, 2024 9:38 pm Post subject: |
|
|
| NeddySeagoon wrote: | Openrc used to shout at me about /usr already mounted until I set it noauto in fstab..
I noticed that was missing. |
Are you still on OpenRC 0.17?
_________________
| NeddySeagoon wrote: | | I'm not a witch, I'm a retired electronics engineer |
| Ionen wrote: | | As a packager I just don't want things to get messier with weird build systems and multiple toolchains requirements though |
|
|
| Back to top |
|
|
NeddySeagoon
Administrator
Joined: 05 Jul 2003
Posts: 54263
Location: 56N 3W
|
| Posted: Mon Feb 05, 2024 9:40 pm Post subject: |
|
|
GDH-gentoo.
Yep.
_________________
Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
|
| Back to top |
|
|
GDH-gentoo
Veteran
Joined: 20 Jul 2019
Posts: 1541
Location: South America
|
| Posted: Mon Feb 05, 2024 9:53 pm Post subject: |
|
|
Then there's your answer 
_________________
| NeddySeagoon wrote: | | I'm not a witch, I'm a retired electronics engineer |
| Ionen wrote: | | As a packager I just don't want things to get messier with weird build systems and multiple toolchains requirements though |
|
|
| Back to top |
|
|
sublogic
Apprentice
Joined: 21 Mar 2022
Posts: 222
Location: Pennsylvania, USA
|
| Posted: Mon Feb 05, 2024 11:42 pm Post subject: |
|
|
| hrnick wrote: | | I have tried to set up initramfs according to the Gentoo Wiki using genkernel [...] |
Genkernel handles /usr on a separate partition out of the box. It installs a file /etc/initramfs.mounts that you can edit as needed.
The /init in the initramfs finds the root device, mounts it on /newroot, checks /newroot/etc/initramfs.mounts and mounts what you specified, taking parameters from /newroot/etc/fstab . In fact, mounting /usr seems to be enabled by default. I don't have a separate /usr, never customized for one, and sure enough, my /run/initramfs/init.log has a harmless note: | Code: | | Failed (1): 'mountpoint -q /newroot/usr' |
because it tried anyway.
| hrnick wrote: | | The question is; how do I know that I have set up initramfs correctly and that it's working? |
To test, boot with a debug option (how to do that depends on your bootloader). The /init will pause three times to a rescue shell:- Before starting udev;
- before setting up the root filesystem;
- before switch_root.
Type exit twice to get past the first two. At the third, look at /newroot/usr . If it's populated, you are ready. Exit again to switch_root and finish booting. |
|
| Back to top |
|
|
hrnick
Guru
Joined: 31 Aug 2002
Posts: 425
Location: Sweden
|
| Posted: Tue Feb 06, 2024 7:38 am Post subject: |
|
|
| GDH-gentoo wrote: | | Also, OpenRC's localmount creates a /run/openrc/usr_premounted file if it finds that /usr is already mounted, you can check that for a clue. |
| sublogic wrote: | | Genkernel handles /usr on a separate partition out of the box. It installs a file /etc/initramfs.mounts that you can edit as needed. |
/run/openrc/usr_premounted exists and /etc/initramfs.mounts seems to be set up to mount /usr already so those are other good signs. Thanks guys!
| sublogic wrote: | To test, boot with a debug option (how to do that depends on your bootloader). The /init will pause three times to a rescue shell:- Before starting udev;
- before setting up the root filesystem;
- before switch_root.
Type exit twice to get past the first two. At the third, look at /newroot/usr . If it's populated, you are ready. Exit again to switch_root and finish booting. |
So this would probably be a next step to feel more comfortable that everything is set up correctly. Thanks! |
|
| Back to top |
|
|
|
Kernel & Hardware
