Hello all, Thanks for the replies and discussion. So following Bernd's suggestion, I tried making a big file to see how big the file system can grow. Using qemu (arm64, I think it will be the same in real machine, it was always almost the same), I tried 'dd if=/dev/zero of=test bs=1M count=768' and I see a file with size 768MB is generated. So it seems it uses the available ram (I had 1GB ram, and the initial file system size was only 19MB) (BTW, I had to do 'mknod /dev/zero c 1 5 in the init script for this) My real board doesn't have disk connected now and we'll be doing things on ram for now. Thank you. Chan Kim >-----Original Message----- >From: Nicholas Mc Guire <der.herr@xxxxxxx> >Sent: Monday, January 2, 2023 4:23 AM >To: Bernd Petrovitsch <bernd@xxxxxxxxxxxxxxxxxxx> >Cc: kernelnewbies@xxxxxxxxxxxxxxxxx >Subject: Re: How is the size of init ram disk determined when initramfs is >used? > >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. > >thx! >hofrat > >_______________________________________________ >Kernelnewbies mailing list >Kernelnewbies@xxxxxxxxxxxxxxxxx >https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
