100% CPU Usage

[rg_software]

Hi all. I would truly appreciate a a good advice.

On my brand new RT-AC88U (fresh Merlin beta build) I am getting a 100% CPU usage with roughly 50/50 load divided between "hotplug block" and "udhcpc leasefail" processes.
It happens when I plug in a USB RAID array (should be visible as a single drive).
I used it with another router in the past, and everything was fine, but now it seems that the new router is utterly unusable

 

[RMerlin]

Hi all. I would truly appreciate a a good advice.

On my brand new RT-AC88U (fresh Merlin beta build) I am getting a 100% CPU usage with roughly 50/50 load divided between "hotplug block" and "udhcpc leasefail" processes.
It happens when I plug in a USB RAID array (should be visible as a single drive).
I used it with another router in the past, and everything was fine, but now it seems that the new router is utterly unusable

Switch to a non-beta.

 

[rg_software]

Switch to a non-beta.

Well, I would expect this answer
There is another problem: the current non-beta version shows Japanese interface only for me. Is there any version that is 'non-beta' and still provides full multilingual interface?

EDIT: Tried with the most recent non-beta, same thing

 

[RMerlin]

I can't think of any logical explanation where you'd end up with both hotplug AND the DHCP client eating full CPU cycles, sorry. Both shouldn't be even remotely related.

 

[sfx2000]

I can't think of any logical explanation where you'd end up with both hotplug AND the DHCP client eating full CPU cycles, sorry. Both shouldn't be even remotely related.

That is strange - wonder if OP did a full reset on the unit after flashing...

Some of that USB RAID/JBOD boxes are just plain weird anyways - SteveCH and I did some nice debug over in the NAS forum on a similar item - and USB3 port complicates things further...

(those boxes tend to run fine under Windows, but many of them don't do the right thing with Linux's USB stack in my experience)

 

[rg_software]

Thank you for comments. I have some more news.

1) I confirmed the same issue with recent Merlin builds AND with official Asus drivers (FW_RT_AC88U_30043803341.zip). So, probably, there is no reason to juggle with the drivers, they all give the same results. Also both USB ports (2.0 and 3.0) work the same way.

2) I narrowed down the problem to my RAID box (Mediasonic ProRaid). A simple usb HDD works fine when attached to the router. I must say, however, that my previous router (Buffalo with DD-WRT) worked perfectly with the RAID device.

3) I understand that DHCP and USB hotplug have nothing in common, so let's focus on USB. I have a feeling that DHCP goes crazy because the router is 100% busy, and some devices at home are trying to connect and constantly get disconnected.

So. May I ask, e.g., if there any way to switch off hot plugging? I don't really need it, I am OK with rebooting the router every time I insert something into a USB port.

Next, since the RAID has also a eSATA connector, I am going to try attaching it via eSATA -> USB adapter. Is there any (third) way to connect it. Say, via Ethernet port (quite improbable...) or via some additional USB device that will make it appear to the router as something more conventional than RAID.

 

[suhail_ssr]

Did you tried disabling the UPnP Media Server from the Media Services & Server settings?
Give it a try and check your CPU usage.

Because the above step has freed my CPU usage