OpenWRT with Raspberry Pi Temp Space Issue

Hi folks

i have a Raspberry Pi running OpenWrt with 4gbs of ram. I get an error about "0kb available on filesystem /overlay".

Usually you'd get that error with too little ram, but with 4 gigs? Is the amount of ram available to the system defined anywhere in that maybe theres only so much ram assigned? I have only really added PHP to the system and was trying to install mysql when I ran into the error

any help appreciated

tmpfs by default uses up to 50% of the RAM available to the OS.

Under 'Software (after I deleted php etc), it. tells me I have 97% free space now - but that equals 85mbs. should I have 2 gigs?

The drive is 35gb and ram is 4gb so Ihave no idea where its getting just under 100mbs storage from

The overlay should not (under normal circumstances) be tmpfs backed, as that would be lost after rebooting, but on the sdhc card. There are guides in the wiki explaining how to resize/ grow the overlay partition and its filesystem.

By default, many OpeNWrt images are sized in a way to fit onto 128 MB media (leaving some gap).


Are you using the ext4 image I assume? Like @slh said, the default root size is 128 MB. If you need more, you can set the size in the nconfig or menuconfig.

I need more so I use:


If you don't need more root partition (ie for packages) you can just create a partition using the rest of the space for your data and then mount that. Just be sure you leave some space after the partitions created by the image in case, one day, you want to expend OW's root size.

thanks for the replies - I'll try that

You're welcome. I do not know if the image builder allows for this tweak. I only even build my own images.