ext4 USB 3.0 drive failing to mount - unsupported optional features

[ColinTaylor]

For example, this guide states, that mkfs.ext4 is shipped only with ARM-routers...

Exactly, that's why Merlin on the RT-AC68U will have mkfs.ext4 (because it's ARM) and why I said the RT-N66U doesn't (because it's MIPS).

does all OEM builds lack mkfs.ext4 tool and it is added only in custom builds or things go other way?

Well the latest OEM for the RT-AC68U only comes with mkfatfs and mkntfs as you know so I suspect that is true for the other models.

EDIT: Well I just picked an older firmware at random (January 2016) and that was the same.

 

[MarCoMLXXV]

Ok, problem solved. I had the same issue as OP It seems, that third-party EXT4 format tools are still not compatible with AsusWRT.

I'm using a Sandisk DataTraveler G3 64 Gb USB-stick, formatted with a 512MB linux-swap partition and two ext4 partitions. I've formatted it with Gparted on Ubuntu 16.04 as wel as with Minitool Partion Wizard 10, on Windows 10, without any problems whatsoever... The documentation (comparison sheet) on the website mentions support until ext3, but it does support ext4 just fine.

 

[Marko Polo]

I'm using a Sandisk DataTraveler G3 64 Gb USB-stick, formatted with a 512MB linux-swap partition and two ext4 partitions. I've formatted it with Gparted on Ubuntu 16.04 as wel as with Minitool Partion Wizard 10, on Windows 10, without any problems whatsoever... The documentation (comparison sheet) on the website mentions support until ext3, but it does support ext4 just fine.

Interesting. Did you use default formatting settings in GParted and Minitool? Did you have ntfs+ext4 partitions on the same disk?

 

[MarCoMLXXV]

Yes, I used default settings. No, I was switching from NTFS to ext4, as it felt kinda weird to have an NTFS partition (for nvram-save) in a non-windows environment. There are some recent posts about it, in the nvram-save thread. You do have to make sure, you erase all partitions before you start repartitioning.

 

[Marko Polo]

Well, I face the problem again, but now on Merlin (I started this thread still being on stock firmware). I am still missing mkfs.ext4 binary in /usr/sbin being on latest Merlin (384.4_2)

-rwxr-xr-x    1 smb root        131104 Mar 24 20:59 mkfatfs
lrwxrwxrwx    1 smb root             6 Mar 24 20:59 mkfs.ext2 -> mke2fs
lrwxrwxrwx    1 smb root             6 Mar 24 20:59 mkfs.ext3 -> mke2fs
-rwxr-xr-x    1 smb root        552604 Mar 24 20:59 mkntfs

Any suggestions?

 

[ColinTaylor]

Use:

mke2fs -t ext4 .......

https://www.snbforums.com/threads/missing-mkfs-ext4-on-asuswrt-merlin-ac-rt-5300.45886/#post-396382