slarm64 (unofficial slackware) Quartz64 RK3566 (aarch64)

[CounterPillow]

if i try this

Code:

   sudo zstdcat slackware-current-*-server-*-build-*.img.zst > /dev/mmcblk0

i get "permission denied"

Because in the latter example, you're only running the cat as root, not the shell redirect. Don't use sudo here, do sudo -i first to get a root shell.