Proposed F19 Feature: Dracut HostOnly

[Lennart Poettering]

On Tue, 29.01.13 14:17, Adam Williamson (awilliam at redhat.com) wrote:

> On Tue, 2013-01-29 at 14:06 -0700, Chris Murphy wrote:
> > Am 29.01.2013 16:55, schrieb Bryn M. Reeves:
> > > Again, unless you have very different storage controllers this will not break.
> > > 
> > > I really don't want or need every FC HBA kernel module, firmware bin file or other junk in my laptop initramfs
> > > "just in case" I happen to swap the disk to a laptop with built-in fibre-channel :-)
> 
> > The proposal not seem to be a significant performance enhancer.
> 
> <snip>
> 
> This is just what I was going to ask for: numbers. I don't see how we
> can make a reasoned decision on a feature whose primary stated basis is
> 'performance', when said feature provides zero data on the claimed
> performance improvement.
> 
> Per Lennart's mail it seems Chris' attempt is flawed, but at least he
> made an attempt. Perhaps the feature proposers could take the time to
> provide some numbers, taking Lennart's feedback into account? The onus
> would appear to be on them.

Full disclosure: I am actually really hoping for Harald's feature to
include something that's not on the feature page right now: and that is
the strongest form of host-only initrd support -- when the root disk is
on a file system and storage that is accessible with compiled-in
drivers, then dracut would skip generation of an initrd entirely.

I have been running Linux regularly with and without initrd in the
F15-F17 cycles (simply since we needed to support both cases with
systemd). Then, booting without initrd usually cut off about 20% of
the boot time.

(I can't give you any up-to-date numbers for that however, since after I
reinstalled my machine in the F18 development cycle I chose btrfs as
root fs. btrfs is currently compiled as module, which means I cannot
boot without initrd. I have now filed this bug so
that I can start testing initrd-less boots again:
https://bugzilla.redhat.com/show_bug.cgi?id=905611 )

Hey, Harald, any chance we can get the non-initrd-where-not-necessary
trick, too? That would be too cool ;-)

Lennart

-- 
Lennart Poettering - Red Hat, Inc.