====== no space left ======

Trying to upgrade:
  * from: ''luci-25.12-snapshot-r32710-f4bab2d12c-ramips-mt7621-netgear_r6220-squashfs-sysupgrade.bin''
  * to: ''luci-25.12-snapshot-r32909-7014bb7ee2-ramips-mt7621-netgear_r6220-squashfs-sysupgrade.bin''

<code>
upgrade: 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
</code>

  * Reason: [[https://forum.openwrt.org/t/openwrt-25-12-1-service-release/247899/67?u=cezary]]
  * Repair: <code bash>rm /dev/null; mknod -m 666 /dev/null c 1 3</code> [[https://eko.one.pl/forum/viewtopic.php?pid=330888#p330888]]