id = 1754
title = "QEMU wrongly requires SD card sizes to be a power of two"
state = "opened"
created_at = "2023-07-07T22:08:46.264Z"
closed_at = "n/a"
labels = []
url = "https://gitlab.com/qemu-project/qemu/-/issues/1754"
host-os = "Linux"
host-arch = "x86"
qemu-version = "8.0.50"
guest-os = "Raspberry Pi OS"
guest-arch = "ARM"
description = """QEMU arbitrarily requires SD card sizes to be a power of 2. However, this behavior does not match the real world, and I am unable to pass a *physical* SD card into the guest operating system.
```
$ sudo qemu-system-aarch64 -M raspi2b -drive file=/dev/mmcblk0,if=sd,format=raw
qemu-system-aarch64: Invalid SD card size: 29.7 GiB
SD card size has to be a power of 2, e.g. 32 GiB.
You can resize disk images with 'qemu-img resize <imagefile> <new-size>'
(note that this will lose data if you make the image smaller than it currently is).
```"""
reproduce = """1. Insert a physical SD card into your host system and make a note of its device name. It will be something like `/dev/mmcblk0`
2. Attempt to start a guest OS with the SD card attached. See the command above.
3. You will get an error saying that the card size is not a power of two."""
additional = """"""