Trying to upgrade:
luci-25.12-snapshot-r32710-f4bab2d12c-ramips-mt7621-netgear_r6220-squashfs-sysupgrade.binluci-25.12-snapshot-r32909-7014bb7ee2-ramips-mt7621-netgear_r6220-squashfs-sysupgrade.binupgrade: Commencing upgrade. Closing all shell sessions. Command failed: Connection failed Watchdog does not have CARDRESET support upgrade: Sending TERM to remaining processes ... upgrade: Sending KILL to remaining processes ... upgrade: Switching to ramdisk... [ 110.413080] UBIFS (ubi0:1): background thread "ubifs_bgt0_1" stops [ 110.442316] UBIFS (ubi0:1): un-mount UBI device 0 upgrade: Performing system upgrade... verifying sysupgrade tar file integrity tar: write error: No space left on device cat: write error: Broken pipe corrupted sysupgrade tar file sysupgrade failed umount: can't unmount /dev: Resource
rm /dev/null; mknod -m 666 /dev/null c 1 3