How is the size of init ram disk determined when initramfs is used?
Nicholas Mc Guire
der.herr at hofr.at
Sun Jan 1 14:23:23 EST 2023
On Sun, Jan 01, 2023 at 06:32:55PM +0100, Bernd Petrovitsch wrote:
> Hi all!
> On 07/10/2022 04:32, Chan Kim wrote:
> >I'm using initramfs.cpio.gz for initial file system image.
> >I embed it in the kernel Image file.
> >After linux boots, when I'm in the shell, I can create files.
> >But I'm curious how much the file system can grow.
> Why not just try it once;-)
ramdisks are static - so if you mount ram0 and ramdisk_size=8192
then your ramdisk is occupying 8MB and that will be the hard limit
at least on some architectures (x86, I think also arm).
> >I remember somewhere reading that the initramdisk is made and the initramfs
> >archive is extracted in the ramdisk.
On some architectures you can pass the size as kernel parameter
ramdisk_size=#kb and that will then set the size of the ramdisk
when you mount it (at boot or during normaal operations).
As I did not find what archtiecture you are refering to this might
help - grep for ramdisk_size in Documentations and you should have
it. E.g. for arm it is marked as obsolete (arm/boot.rst) but still
seems to be supported with CONFIG_DEPRECATED_PARAM_STRUCT set.
Wonder what it is being replaced by.
More information about the Kernelnewbies