[SOLVED]Linksys WRT32X - Where is free space of flash memory?

[oslyak]

By tech specs WRT32X has 256Mb of flash memory.

# /bin/df -h
Filesystem                Size      Used Available Use% Mounted on
/dev/root                 3.0M      3.0M         0 100% /rom
tmpfs                   250.0M      1.3M    248.7M   1% /tmp
/dev/ubi0_1              97.9M     21.4M     71.7M  23% /overlay
overlayfs:/overlay       97.9M     21.4M     71.7M  23% /
tmpfs                   512.0K         0    512.0K   0% /dev

Mounted only /dev/ubi0_1 with 97.9Mb
In dev there is /dev/ubi0_0
But I could not mount it

# mount /dev/ubi0_0 /mnt
mount: mounting /dev/ubi0_0 on /mnt failed: Block device required

Where is 150Mb of free space flash?

[trendy]

Maybe this schematic will help.
Keep in mind that it can host 2 OSs.

[oslyak]

Understood, thank you.