Ezt adja a df -h és a mount:
root@OpenWrt:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 3.3M 3.3M 0 100% /rom
tmpfs 28.6M 236.0K 28.3M 1% /tmp
tmpfs 28.6M 84.0K 28.5M 0% /tmp/root
overlayfs:/tmp/root 28.6M 84.0K 28.5M 0% /
tmpfs 512.0K 0 512.0K 0% /dev
/dev/mtdblock4 2.7M 2.7M 0 100% /rom/overlay
root@OpenWrt:~# mount
/dev/root on /rom type squashfs (ro,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,noatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,noatime)
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelega te)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noatime)
tmpfs on /tmp/root type tmpfs (rw,noatime,mode=755)
overlayfs:/tmp/root on / type overlay (rw,noatime,lowerdir=/,upperdir=/tmp/root/ upper,workdir=/tmp/root/work)
tmpfs on /dev type tmpfs (rw,nosuid,relatime,size=512k,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,mode=600,ptmxmode=000)
debugfs on /sys/kernel/debug type debugfs (rw,noatime)
none on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,noatime,mode=700)
/dev/mtdblock4 on /rom/overlay type jffs2 (rw,noatime)

Extroot megoldhatja esetleg? Semmilyen csomagot nem telepítettem rá, a luci is azt írja, hogy 99% szabad hely van rajta.