ext3 mkdir stuck 2 minutes 99% IO

[maryhit]

Hi,

First of all congratulations for the distribution to Merlin and all those working on it.

I am trying this distribution with the hope that fixes an issue I encounter with the official one on my RT N16 with an WD Passport 2TB USB3, but unfortunately it's not the case..

I formatted it ext3, and I loaded it with lots of data (only ~250 GB left free).

The issue is that when I create a folder (either via shell or via samba) it gets stuck for ~2 minutes. Top shows 99% IO.
System log does not show any error, nor I get any error when doing mkdir from command line.

Of course I did check the disk, all is fine. Moreover, when I move the disk to a laptop with Ubuntu installation, everything works fine, directories get created instantly without any delays, etc.

If helps, mount params on the router:
/dev/sda5 on /tmp/mnt/sda5 type ext3 (rw,nodev,noatime,data=ordered)

Are there some more details I can present, any debug flags, etc?

Thanks in advance for any tips/ideas.

 

[RMerlin]

Not sure what that could be, sorry.

You could try disabling its journal to see if that helps.

Is it a bus-powered disk (drawing its power through the USB cable)? I've had quite a few bad experiences with that type of disks in the past, where sometimes even a normal desktop would fail to provide enough power for the disk to work reliably. It would surprise me that this would be the reason however based on your symptoms - that would usually generate quite a few errors in Syslog.

 

[tonysamson]

could it be that your enclosure is not compatible with the router?

 

[maryhit]

more tests

I've done some more tests, now using a powered USB hub and still the same issue. It is clearly something related to the software on the router. Either kernel, or samba or something like this.
I have tried the same hdd connected to a linux machines, and I connected to that linux box (openelec on RPi) via samba and I was able to create folders (via samba) and use hdd without any issue...
It could be some incompatibly between: RT N16 - WD 2TB passport - EXT3 (and Samba)...
Both default OS and Merlin version behave identically from this issue point of view.

If anyone has any hints, it would be highly appreciated.

 

[maryhit]

some more tests

After some more tests (including factory reset, etc), it seems the stuck situation appears only on directories with lots of subdirectories.
E.g. when I mkdir abc under a directory with ~1150 subdirectories/files, it takes very long, but in ones with less, it's fast.

And this happens only on the router. When I move the hdd on a ubuntu machine, it's blazing fast. It must be an issue with the way ext3 is implemented/mounted on the Asus router I guess.

Or any idea what other options are there? How to tune the FS further, how long till ext4 or at least an improved version of ext3 will be implemented?

Do you know if there a way to open a defect on Asus website? I've posted there, but no answer, it looks like a desert of support/knowledge there compared to this forum