GL-AR750 disk space / layout


I just got my GL-AR750, and trying to set it up like I’ve done before with the AR_300m. However, the disklayout on my new AR750 is much different:

root@GL-AR750:/etc# df -kh
Filesystem Size Used Available Use% Mounted on
/dev/root 8.3M 8.3M 0 100% /rom
tmpfs 61.1M 1.2M 59.9M 2% /tmp
/dev/mtdblock6 6.1M 1.6M 4.5M 27% /overlay
overlayfs:/overlay 6.1M 1.6M 4.5M 27% /
tmpfs 512.0K 0 512.0K 0% /dev

This seems to leave only ~4MB for /etc. This is not nearly enough to keep my rather large OpenVPN configuration set, which currently is a total of 33MB. Where is all the disk space going? Or is the disk on this device this much smaller compared to the AR300 ?

I know I can install an external disk, so I’ll obviously look into that (hints welcome how to do this right). But curious if there’s something I’m doing wrong here first?


– Leif

The device of GL-AR750 with 16MB nor flash, and the total size of the firmware about 11MB, so it leaves ~4MB, that’s normal. As you say, AR300M with 128MB nand flash, it is enough for you to keep your large OpenVPN configuration files.

Ah, ok. Are there any details on how what packages are needed to mount an external micro SD card? And perhaps even some details on how I’d make e.g. /etc mounted on that card? I can probably figure it out myself, but if there are details already documented, I figure it might save me some hassles and potential for “bricking” :-).


– Leif

You may want to try extroot. It allows you to mount the entire filesystem on an external SD card. I’m currently using it on my AR750 with a 64GB Samsung MicroSD card and it works perfect :grinning:

Great! I was looking at that, but wasn’t sure if it applied to our system :). I’ll give it a shot, worst case I’ll recover with a firmware reset presumably? :-). Did you just follow the instructions as outlined in that Wiki page, or did you have to do anything special? What FS did you use, ext4?

I’ve just ordered a 32GB Samsung Micro SD, which I think will be plenty big.


– leif

If it doesn’t work and your router gets bricked, you can always restore the firmware using the Uboot utility (make sure you have a firmware.bin file downloaded before you try extroot!) with the steps here. I am using ext4 on the partition on my SD card holding the OS, but I also added a 512MB swap partition (you can do this if you want but it’s not strictly necessary).

The only thing I had to do that isn’t in the wiki page is edit the mountpoints, the guide uses /mnt as the mountpoint of the SD card but I had to mount the SD card in a subdirectory of /mnt (if you don’t mount your SD card at /mnt make sure you replace all instances of /mnt with your mountpoint, especially on the step where you copy the contents of the NOR flash to the SD card, otherwise you will probably brick your router).

The exroot procedure worked great for me. Thanks to you that suggested it and main of all to who documented it!
I used this memory:
The router (GL-AR750) performs very well and I’ve a lot of space to use for add-ons and VPN configurations.
Bye. LP

overall great idea, but have to ask -
what do you do when a new firmware is released? what would be the migration/upgrade method?

Hi AnonyOne
Honestly, it’s the first time I bought a GL-iNet router and so I’m not so experienced in advanced management. My router was already updated with the latest available firmware; so I actually don’t know what will happen when a new firmware release will be available and installed.
I hope the upgrade will be ‘transparent’. In any case, I regularly take a backup of the configuration and I keep a log of additional plugins I install. So, if something will go wrong I am able to restore the router configuration after re-configuring the disk ‘layout’.
If someone knows what happens when a new firmware release is installed on a router with ‘custom disk layout’ and which ‘countermeasures’ can be taken to avoid reconfiguration, please provide some hints …
Bye. LP

Hello thanks for the information but Can you share what you actually did with setting up the sd card – im totally cluesless thanks

It can be its supported now on 3.2 gl firmware and can be found on advanced admin menu. A how too of how to use are not now for me. A it can be more information can be found on openwrt website, where this feature was implemented in openwrt and the primary part of firmware are from.