Re: Can the grub2.02 improve the limit of initrd size in 64-bit system?

[Chris Murphy]

On Wed, Jul 31, 2019 at 2:18 PM Vladimir 'phcoder' Serbinenko
<address@hidden> wrote:
>
> > So 32 bit arm requires kernel + initrd less than 512MB, 64 bit
> > arm requires kernel + inirrd less than 32GB.  If I read the code
> > correctly, booting x86 in efi mode the max initrd file allocation is 1GB
> > (0x3fffffff).  Seems the code is shared for 32 and 64 bit EFI and doesn't
> > allow anything more on 64 bit than 32 bit.  Of course no normal system
> > would ever need more so no point implementing it.
> >
> > A 1GB ramdisk would be plenty to start a system that could then load more
> > ramdisks if it really wanted to.  Could any sensible use case exist for
> > loading an initrd that large?
>
> I agree. I don't think that implementing support of > 1GiB ramdisk
> makes sense unless we have a usecase in mind.
>
> Original reporter: can you please ellaborate why you need such a large
> ramdisk and why you can't let kernel mount additional images?

And also for such a large file, is there sufficient I/O support for
quickly reading it? I vaguely recall some work had to be done in the
kernel to get it to support faster storage devices such as NVMe.

A possible use case would be resuming from a hibernation image.

-- 
Chris Murphy