[SOLVED] f2fs root partition content cpd to ext4 root part won't boot

jamtat · 2017-12-23 14:04:07

I'm dealing with a strange problem when trying to boot to an Arch install I've copied from an f2fs partition to an ext4 partition (/boot, incidentally, resides on yet another partition). The bootloader (syslinux) finds the kernel and initramfs but, although the entry that specifies the f2fs root partition eventuates in an operational Arch environment, the entry that specifies the ext4 partition as the root partition fails and drops me to a maintenance shell.

Indications from console messages I get when the ext4 boot process fails, lead me to believe that the reason for the failure may lie in the fact that important element(s) for dealing with the ext4 file system is/are missing from the initramfs. The initramfs was generated manually--the mkinitcipio.conf file having been edited so as to specifically include f2fs modules--while, as I recall, the system was booted under the f2fs root partition. From what I'm reading on the wiki I gather that, if no ext4 partition was mounted at the time of the initramfs's generation, the ext4 kernel module may well not have been included in it. Is my understanding about that correct?

I just wanted to double check here because, since the ext4 file system is so widely used, my supposition would be that its module would not be created as a loadable one during kernel compilation. I would think, rather, that it would be compiled into the kernel. But that's a guess--one that could be verified or dismissed by taking a gander at the kernel config, I suppose.

I see two possible ways to proceed: 1) add the ext4 module to the "modules" line of mkinitcpio.conf and regenerate the initramfs, or 2) boot into the working f2fs environment, mount the ext4 partition, then regenerate the initramfs. Am I correct in understanding that the two are more or less equivalent when it comes to inclusion into the initramfs of what will be needed in order for the system to deal with an ext4 root partition? If so, is there any reason to prefer one over the other? Input will be appreciated.

Last edited by jamtat (2017-12-23 22:56:34)

R00KIE · 2017-12-23 15:38:10

Your reasoning seems to be going in the right direction, I would also guess the problem is a lack of the ext4 module in the initramfs.

There is a third option that might work and you have considered, boot with the fallback initramfs. If this works, regenerating the initramfs should now add the ext4 module, or you could always go the way of the first option and explicitly add to the initramfs the fs drivers you need now and the ones think you might need in the future.

jamtat · 2017-12-23 17:50:40

It was really easy to do so I just added ext4 to the modules line of mkinitcpio.conf and regenerated the initramfs. The system booted just fine this time under the root file system I'd copied over to the ext4 partition from the f2fs partition. That shows the problem I was seeing was, in fact, related to the ext4 module missing from the initramfs. I'll just have to suppose that mounting the ext4 partition prior to regenerating the initramfs would have had the same effect and would have obviated the need to modify the mkinitcpio.conf file. At least that's what I infer from the wiki article's statement that "If you will be needing any file system during the boot process that is not live when you run mkinitcpio . . . that file system module must also be added to the MODULES list."

R00KIE · 2017-12-23 18:59:56

Don't forget to edit your first post and add [SOLVED] to the title if your problem is solved[1].

[1] https://wiki.archlinux.org/index.php/Co … ow_to_post

jamtat · 2017-12-23 21:35:59

R00KIE wrote:

Don't forget to edit your first post and add [SOLVED] to the title if your problem is solved

Will do. Just wanted to hold off a bit longer in case someone else might have some further input on whether a mounted file system would have the same effect when it comes to regenerating the initramfs.

Last edited by jamtat (2017-12-23 21:36:29)

Scimmia · 2017-12-23 21:48:58

That's exactly what the autodetect hook does

Arch Linux

#1 2017-12-23 14:04:07

[SOLVED] f2fs root partition content cpd to ext4 root part won't boot

#2 2017-12-23 15:38:10

Re: [SOLVED] f2fs root partition content cpd to ext4 root part won't boot

#3 2017-12-23 17:50:40

Re: [SOLVED] f2fs root partition content cpd to ext4 root part won't boot

#4 2017-12-23 18:59:56

Re: [SOLVED] f2fs root partition content cpd to ext4 root part won't boot

#5 2017-12-23 21:35:59

Re: [SOLVED] f2fs root partition content cpd to ext4 root part won't boot

#6 2017-12-23 21:48:58

Re: [SOLVED] f2fs root partition content cpd to ext4 root part won't boot

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