Defect report : Random reboot when there is transfer load from USB HDD

[algorab]

I've noticed something else which is disturbing. As long as I use the router strictly for traffic routing, it is rock solid.

As soon as I connect a USB HDD and use it as a sort of NAS, the router becomes unstable. What I can see is that when I stream data from the attached HDD to a media player, at some point, the router will reboot.

I can see this behaviour with both SMB and NFS access to the data, so my guess is that maybe there is an instability of the USB subsystem of the OS.

Of course, when this happens, the USB HDD is no longer detected properly, so it is not auto-mounted.

Not only it is annoying that the router reboots, but then I have to make a manual intervention so that I can access the data again, as explained in a previous defect report.

It looks like the solution to this problem, as long as there is no patch coming frm ASUS to fix it, is to use a true NAS. Which is a bummer and really dissapointing.

 

[ColinTaylor]

Which model of router? Which firmware version?

 

[algorab]

The router is RT AC66U and the firmware is AsusWRT-Merlin 376.48_3

 

[RMerlin]

NFS is known to be unstable on MIPS-based routers, due in good part to the old kernel being used by it. I have never been able to track down the cause.

I don't have any other report of SMB accesses leading to a router reboot however. Combined with your report of having trouble getting your HDD recognized by the router, I would suspect it's a compatibility issue.

 

[algorab]

I have found a solution to the problem of having the HDD partitions detected by the USB driver and it is a script which unbinds all the USB devices and then binds them back, thus forcing the driver to read them again.

This way I can get the HDD mapped correctly and the partitions mounted, without having to unplug and plug back.

The only thing that remains to do is write a script which will verify periodically the state of the HDD mount and if it is not mounted correctly, to force the detection and re-mounting. Thus, even if there is a reboot, anoying as it may be, I have a solution for auto-mount.

As for your statement that NFS is unstable, that may be so, but I found that it is the only way to have graceful recovery of the connection to the network resource in case the connection is dropped in the middle of an operation. With SMB, the mount that is left behind is in an unclean state that prevents correct unmounting and remounting.

By the way, on the client side, I have only Linux based computers, and with the router being a Linux OS too, it makes sense to me to use NFS instead of SMB. But, I will monitor this and see if, indeed, I can spot the NFS instability you mentioned.

 

[RMerlin]

https://github.com/RMerl/asuswrt-merlin/issues/280

 

[algorab]

Thank you Merlin. Now, I will have to do a set of tests of my own to try and figure out the context in which an unexpected reboot occurs.

 

[algorab]

I've done a small test (more to do) last night. I streamed a 2GB file which contains a movie to my multi-media player, using both SMB and NFS. Surprisingly, when I did it over SMB at some point the router crashed and rebooted. When I did it over NFS it was rock solid.

Next, I will do file copy with a 4GB file using both SMB and NFS and see what happens.