Curious df output

[oliv]

Hi,
I just started with OpenWRT and I found curious the output of df:

root@OpenWrt:/# df -Th
Filesystem           Type            Size      Used Available Use% Mounted on
/dev/root            squashfs        4.5M      4.5M         0 100% /rom
tmpfs                tmpfs          60.7M    340.0K     60.4M   1% /tmp
/dev/mtdblock9       jffs2           9.0M      5.0M      4.0M  56% /overlay
overlayfs:/overlay   overlay         9.0M      5.0M      4.0M  56% /
tmpfs                tmpfs         512.0K         0    512.0K   0% /dev

It says the total size for / is 9.0M however I have placed myself a 10.4M folder in it and there is still some space available (4.0M). Is df the recommended tool to check storage in OpenWRT?

root@OpenWrt:/apps# pwd
/apps
root@OpenWrt:/apps# du -sh
10.4M	.

[frollic]

It's compressing the content

How to check real available storage space in LEDE (wrt1900acs)

Hi I would like to get the real available storage space in my router. When I use df -h I get the following: root@LEDE:~# df -h Filesystem Size Used Available Use% Mounted on /dev/root 2.8M 2.8M 0 100% /rom tmpfs 250.8M 1.1M 249.7M 0% /tmp /dev/ubi0_1 23.5M 56.0K 22.2M 0% /overlay overlayfs:/overlay 23.5M 56.0K 22.2M 0% / ubi1:syscfg 29.6M 252.0K 27.8M 1% /tm…

[oliv]

oh I see. That must explain why I thought writing files to it was a bit slower compared to /tmp. Also is df output referring to uncompressed size?

[frollic]

I would assume it shows the worst case scenario, if something that's uncompressable, like a ZIP, would be put there.

My 2nd guess would be based on current compression ratio.