Re: [Qemu-devel] alpha platform is missing files after initrd load

[Laszlo Ersek <lersek@redhat.com>]

On 11/07/16 15:38, Dennis Luehring wrote:
> Am 07.11.2016 um 15:12 schrieb Laszlo Ersek:
>> The second error message is incorrect in its own right (it's just
>> another symptom of running out of memory;
> there a two cpios
> 
> big(~370MB) initrd.cpio + 1GB ram gives only this message: "Initramfs
> unpacking failed: write error"
> small(~14MB) initrd.cpio + 1GB ram gives only this message: "Initramfs
> unpacking failed: junk in compressed archive"
> 
> so the second one couldn't be a problem with running out of memory - and
> its not alpha related same error happens with ppc64,sparc64,mips64...

The second one *is* related to running out of memory. Initrd
decompression takes unintuitive amounts of memory. And, in practice,
exactly the second error message was seen with the aarch64 target, until
Rich Jones raised the guest RAM size that libguestfs passed to QEMU.

You can try it for yourself: stick with the small (14MB) initrd, and,
say, quadruple the guest RAM size. I'm pretty sure it will succeed.

The difference between the error messages (and the initrd sizes) is that
the initrd decompression runs out of memory at different stages. With
the huge initrd, unpacking likely fails in one of the early stages. With
the smaller one, unpacking likely fails later. I never bothered to
figure out where exactly.

Thanks
Laszlo