How to expand storage for software installation?

My d-link dir-2660 has 128MB rom, but the storage allocated for installing additional software is just 27MB and now has only 7MB free. I've read this instruction, but I'm not sure it exactly matches my rom structure.
[OpenWrt Wiki] Extroot configuration
How do I expand this software storage by using the unused rom space?...thanks.

My current rom structure:

If you follow the extroot instructions, the initial partitioning doesn't really matter.

Thanks. The instruction is using usb flash drive as an overlay instead of the internal one. For my case, I want to use the unused space in ROM, but I don't know which /dev/? is the free rom space in order to make it an overlay replacement.

cat /proc/mtd

which one? or other question, is it technically possible to expland the /dev/ubi0_1?

Okay. We can't use the internal unused storage to extend the overlay size. I've followed the Exroot config and use a USB flash drive partition as an overlay successfully.

There is one side effect. Reboot the router either from Luci gui or command line won't actually reboot it at all. I have to manually switch off and on at the router. What may have caused the issue, and any solution for this?

Another question is, before I did the exroot process, the USB flash drive was formatted into 3 ext4 partitions (dev/sda1, 2,3). After the exroot process, the first partition is now an overlay. I intend to mount the dev/sda2, and 3 as another two mount points for other usage. However, both do not show up in the list (Luci-->Systems-->Mount Points-->Add) when I want to add a mount point. Is it supposed to be like this?


I would also like to use unused ROM space. This was the reason to buy DIR2660 router. Is there some reason to not use all internal ROM? Maybe because A1 does not have as much space as A2?

Me too.

My Archer C7 V5 has 15 MB for ROM, but only 2.3 MB are used.

Is it possible, to move packages from overlay partition to ROM partition?

Sorry, I have to correct myself: /dev/mtdblock8 for /rom is 13 MB, and 2.3 MB are used. Overlay has about 11 MB free. This all with the standard image for the Archer C7 V5.

This afternoon I build a custom image (with the help of, which includes much more packages than the standard build.

After a successful flash I get the following usage:

/dev/root      squashfs  7680 7680    0 100% /rom
/dev/mtdblock9 jffs2     5760  296 5464   5% /overlay

I gain about 5.3 MB in /rom, but loose about 5.3 MB in /overlay. So in total: nothing.

Is it possible, to move packages to /rom and have more free space in /overlay?

No, you can't.

You have 15'728'640 bytes in total at your disposal, for kernel + rootfs (/rom) + overlay, the split among them is dynamic. Including packages into the read-only rootfs is only possible at build-time (imagebuilder or building from source). In general, compression of squashfs (rootfs, /rom) should be slightly better than for the jffs2 backed overlay.

I suspected it :slightly_frowning_face:

Does this apply just for the C7 or for every device with flash memory?

Nevertheless, thanks for your clarification. I appreciate your infos.

The absolute figure applies to the c7 v5 only, the principle is similar for all devices. The amount of usable flash storage depends on the size of your flash and your vendor's original partitioning (there can be less fortunate choices in terms of partitioning, leaving only small amounts usable despite larger physical flash chips).

Many of us need extra storage for software and games installation, if your computer is running out of storage, then you need to expand the storage. It is quite simple to increase the capacity of the hard drive on your Windows 10 PC. This article will guide you on how to expand storage for software installation.

Openwrt != windows.

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He talks about it being as easy as in Windows.

I'm not so sure about that...

This certainly sounds like a discussion about Windows. But...

whatever article was referenced was not actually linked, so who knows.

I'm sure he was talking about increasing space in OpenWrt just as easily as in Windows.