growdisk on RPi4 with sfdisk instead of parted (signaling kernel)

[stlachev]

We are using now sfdisk instead of parted. The SD card last partition grows till the end, but we cannot signal kernel to update the size in order tools as: df -h to see it. fdisk -l works fine Upon reboot everything is ok and all tools show the correct size. How we can signal kernel to rescan for new size. echo 1 > /sys/block/$DEVICE/device/rescan didn't work raspberry-growdisk.sh

[mikehaller]

I think the echoing to /sys is doing a device-level rescan, not a partition-table re-read.

partprobe seems to be part of the parted package, so we would not be able to use that (license).

blockdev is mentioned by sfdisk as a replacement for the legacy -R option of sfdisk. If it's the one from https://github.com/util-linux/util-linux it would be GPL-2

Unfortunately, when i run it on the shell, i get the following:

blockdev --rereadpt /dev/vda
blockdev: ioctl error on BLKRRPART: Device or resource busy

Not sure, but partx is available on the image, so you may also try something like partx --update /dev/

Ref.:

• https://www.2daygeek.com/how-to-reload-partition-table-in-linux-without-system-reboot/

[d-s-e]

fixed with https://github.com/eclipse-leda/meta-leda/commit/21d86efde707246cf3fa1deed37c49e3ce88db05