Re: [gentoo-user] My first initramfs

[Tanstaafl <tanstaafl@libertytrek.org>]

On 2013-11-12 5:50 PM, Canek Peláez Valdés <caneko@gmail.com> wrote:
> You*MUST*  add the necessary modules/tools to mount root and/or /usr.
> So if you have an XFS partition on a LVM volume on top of an mdraid,
> and the partition is encrypted, then you need the kernel modules for
> xfs, lvm, mdraid and crypt, and the corresponding userspace tools,
> including fsck.xfs.

Ok, re-reading these messages, this explanation is probably the most 
significant - thanks Canek - but I still have a few questions...

Maybe part of my confusion stems from use of the word 'modules' above? 
Remember, the system I am talking about has always had kernel module 
support completely disabled (everything is built into the kernel).

So, my /usr is reiserfs (built into the kernel - and please no 
filesystem flame-war comments, it is what it is) on LVM (built into the 
kernel) on hardware RAID (driver built into the kernel), with no 
encryption involved.

So, am I correct that I don't need ANY 'modules' (never have, and don't 
want them), leaving only the userspace tools for lvm and reiserfsck?

If so then the only other question is, how to build an initramfs with 
just these...

> I strongly recommend dracut; the modules listed in DRACUT_MODULES are
> usually self explanatory, and it Just Works™.

Ok, well, emerge -pvuDN dracut gives:

> [ebuild  N    ~] sys-kernel/dracut-034-r1  USE="-debug -device-mapper -net (-selinux)" DRACUT_MODULES="-biosdevname -bootchart -btrfs -caps -cifs -crypt -crypt-gpg -crypt-loop -dash -dmraid -dmsquash-live -gensplash -iscsi -livenet -lvm -mdraid -multipath -nbd -nfs -plymouth -ssh-client -syslog -systemd" 272 kB

First question: I don't see reference to reiserfs there anywhere, so how 
do I get reiserfsck (and is that all I need?) support into the initrams?

Second question: I guess I'd need to enable the device-mapper USE flag 
for dracut, but, since I do not use ANY kernel modules, can I ignore all 
of the 'DRACUT_MODULES'? Or do 'DRACUT_MODULES' have nothing to do with 
kernel modules?

Thanks to all for your patience...