CPU 100% on ac86u

OBENZ

Regular Contributor
Hello, si I have been experiencing some issues for a couple of weeks now. My ac86u is showing 100% CPU after few hours of operating and out of nowhere I start seeing this
Oct 6 07:07:56 kernel: bcm63xx_nand ff801800.nand: intfc status c80000e0 Oct 6 07:07:59 kernel: bcm63xx_nand ff801800.nand: timeout waiting for command 0x1 Oct 6 07:07:59 kernel: bcm63xx_nand ff801800.nand: intfc status f00000e0 Oct 6 07:08:00 kernel: bcm63xx_nand ff801800.nand: timeout waiting for command 0x1 Oct 6 07:08:00 kernel: bcm63xx_nand ff801800.nand: intfc status f00000e0


Any idea what's wrong?I hope the hardware is not failing
 

OzarkEdge

Part of the Furniture
Hello, si I have been experiencing some issues for a couple of weeks now. My ac86u is showing 100% CPU after few hours of operating and out of nowhere I start seeing this
Oct 6 07:07:56 kernel: bcm63xx_nand ff801800.nand: intfc status c80000e0 Oct 6 07:07:59 kernel: bcm63xx_nand ff801800.nand: timeout waiting for command 0x1 Oct 6 07:07:59 kernel: bcm63xx_nand ff801800.nand: intfc status f00000e0 Oct 6 07:08:00 kernel: bcm63xx_nand ff801800.nand: timeout waiting for command 0x1 Oct 6 07:08:00 kernel: bcm63xx_nand ff801800.nand: intfc status f00000e0


Any idea what's wrong?I hope the hardware is not failing
If it's a clean install, then the hardware may be failing.

The log entries sound related to bcm/radio chip(?) and nand memory(?). Just guessing here.

I'd make a warranty call and discuss it sooner than later.

OE
 

OBENZ

Regular Contributor
If it's a clean install, then the hardware may be failing.

The log entries sound related to bcm/radio chip(?) and nand memory(?). Just guessing here.

I'd make a warranty call and discuss it sooner than later.

OE
This will be the second 86u that would be failing on me, never buying this pos again, warranty is long gone since I bought this one in 2018. I'm still on .17 it think as I haven't updated to .19 yet fearing it would cause problems
 

OzarkEdge

Part of the Furniture
This will be the second 86u that would be failing on me, never buying this pos again, warranty is long gone since I bought this one in 2018. I'm still on .17 it think as I haven't updated to .19 yet fearing it would cause problems
It's not a perfect World.

OE
 

OBENZ

Regular Contributor
I turned off vpn, both wifi radios and the messages haven't stopped maybe it's my external HDD causing problems as that's where the jffs partition is ?
 

Vimes

Regular Contributor
This will be the second 86u that would be failing on me, never buying this pos again, warranty is long gone since I bought this one in 2018. I'm still on .17 it think as I haven't updated to .19 yet fearing it would cause problems

Do they not come with a three years warranty, it should still be covered...?
 

ColinTaylor

Part of the Furniture
... maybe it's my external HDD causing problems as that's where the jffs partition is ?
JFFS is the internal flash partition, nothing to do with HDD.

Did you try RMerlin's advice that I quoted in post #2?
 

OBENZ

Regular Contributor
Could be a problem with the external drive. Are you running any scripts?
Bingo, I haven't had visited snb for a few days so without even reading your suggestion I decided to disable historical statistics which is the only thing using my external HDD, and the issue stopped...I wonder what is wrong ?bad hdd or should I format jffs and try again ?
 

gattaca

Senior Member
If you have been using a USB stick, this could be the root of your issues. Unplug it and turn off those stats and see how the unit responds.
There are several threads where we have suggested using a USB SSD drive in a good, reliable USB case vs the USB sticks. This surfaces quite often with people using AMTM as they start having performance problems, like CPU goes to 100%, b/c the sticks are wearing out and causing all sorts of I/O issues.

USB Sticks contain some of the lowest grade NAND produced and are not designed for heavy I/O writes over longer time periods. Several people here have recommended using the UGREEN USB cases b/c we've had very good results with them. There are a lot of USB SSD cases out there, some of them are *@(@* junk so be-aware. I had an older 80GB Intel SATA SSD collecting dust from when I upgraded to a larger one. It has been working perfectly for 3+ years in a UGREEN USB/SATA case and the I/O rates are great! It stays cool and I just lay it behind the unit. The NAND in these is much higher quality. Also, only use the USB 2.0 port, not the 3.0 port. I've not had a lot of luck with that 3.0 port being ultra reliable. YMMV.

Search for "UGREEN" and it will surface many posts about similar issues along with links to the UGREEN cases on Amazon. There's one thread showing the dramatic performance improvements across many NAND devices and the USB/SSD solution is always near the top over the sticks on many fronts: performance, reliability, ...

Here's but one example -> https://www.snbforums.com/threads/amtm-the-asuswrt-merlin-terminal-menu.42415/page-116#post-598942

Stay safe, stay alive. Peace.
 
Last edited:

OBENZ

Regular Contributor
Thanks for the recommendation but I'm actually using a usb3 1tb hdd from WD and never experienced any isuee with it. For now I just disabled usage statistics and all is well no more cpu spikes and slow downs not any errors in the logs
 

Vimes

Regular Contributor
Thanks for the recommendation but I'm actually using a usb3 1tb hdd from WD and never experienced any isuee with it. For now I just disabled usage statistics and all is well no more cpu spikes and slow downs not any errors in the logs
That's interesting as I have the same drive. I take it that there is enough power on the USB 3 port to use those type of drives, not connected mine as yet.

Thanks
 

OBENZ

Regular Contributor
That's interesting as I have the same drive. I take it that there is enough power on the USB 3 port to use those type of drives, not connected mine as yet.

Thanks
Im sure the drive itself got some problems as I have been running the same setup for more than a year and this issue only showed up recently
 

Vimes

Regular Contributor
Im sure the drive itself got some problems as I have been running the same setup for more than a year and this issue only showed up recently

ah, thanks. I might need to read up to see if the USB 3 port on my AX88U router supplies enough power to use a mechanical type external drive, rather than a USB stick etc.
 

gattaca

Senior Member
^^^ I should be definition if the ASUS engineers did their jobs. But on the AC86U we've seen "reboot = power off" issues which I believe are caused by a slightly under powered PSU wall wart. I and others have posted about that too and fixed our units by buying a beefier PSU. ;)
But back to the USB 3.0... the issue is the increased "electrical noise" on those USB 3.x ports that causes problems in these routers.

I once tried to use the USB3.0 port on my AC86U with a real USB/SSD. I had repeated weird I/O issues until I moved it back to the USB 2.0 port where it has been purring like a kitten for years. My point is your stats might work just fine with a faster, lower-latency SSD.

As for using an HDD USB SATA drive, the I/O rates and latencies on that spinning rust will be dismal compared to any USB/SSD. All the I/O waits that generates would shock you. Does it matter for a router setup - it depends on your objectives. YMMV.

If you have the chance to swap it to USB/SSD, I'd do in a heartbeat and never look back. Of course I work in performance engineering. ;)
 

Matthew Patrick

Senior Member
Actually. You don't need an SSD . Just use a good micro-sd to USB adapter with the new SanDisk Max Endurance lineup. 32gb is quite cheap and the TBW is about 150++ . 40MBps/40MBps on USB 2 is more than enough. With that good of TBW it's a set and forget drive for scripts etc. If you need higher TBW , get the higher capacity ones. But I reckon 150++ TBW is more than enough.
 

Vimes

Regular Contributor
^^^ I should be definition if the ASUS engineers did their jobs. But on the AC86U we've seen "reboot = power off" issues which I believe are caused by a slightly under powered PSU wall wart. I and others have posted about that too and fixed our units by buying a beefier PSU. ;)
But back to the USB 3.0... the issue is the increased "electrical noise" on those USB 3.x ports that causes problems in these routers.

I once tried to use the USB3.0 port on my AC86U with a real USB/SSD. I had repeated weird I/O issues until I moved it back to the USB 2.0 port where it has been purring like a kitten for years. My point is your stats might work just fine with a faster, lower-latency SSD.

As for using an HDD USB SATA drive, the I/O rates and latencies on that spinning rust will be dismal compared to any USB/SSD. All the I/O waits that generates would shock you. Does it matter for a router setup - it depends on your objectives. YMMV.

If you have the chance to swap it to USB/SSD, I'd do in a heartbeat and never look back. Of course I work in performance engineering. ;)

Thanks for that. I also have a USB enclosure for a SSD that I could use. It was more of having this USB HDD 1TB spare that I thought of using it attached to the AX88U, my 86U is now acting as a node in a AI Mesh setup.
Point taken in regards to the PSU, the 88U does seem more substantial, I would need to check their output. What also factors is not only the output of the PSU but if it could supply the power needed to the port for a mechanical HD. AS I do have a SSD choice that would be the preferred option.
I thought of the USB 3 port not because of the faster transfer but that port, if the spec is adhered to, is supposed to be able to carry more power.
 

gattaca

Senior Member
^^^ An SSD will consume less power than a spinning HDD motor. I never considered the USB 3.x spec for power delivery so maybe good point. You don't need a large capacity SSD at all. I've got a 6+ year old 80GB now-ancient Intel that's purring away for 2+ years as the AMTM+Entware+Swapper target on USB2.0. Not hot, no issues.

I'm reporting only my experiences with the USB3 port on my AC86U units. I have no other units with USB SSD attached. FWIW, I also replaced the PSU on these AC86U with the larger ASUS PSU which we covered in another thread. After that, never had another "power-off on reboot...."

I've gotten better I/O reliability and stability using the USB 2.0 with my UGREEN USB/SATA SSD setup. I tried a good USB-key early on and ended up with various issues. Today, I never have to unplug the drive when rebooting and it seems rock stable for whatever I/O the AMTM scripts + Entware + Swapper hit it with. I also tried moving the USB drive to USB 3.0 with the whole 384.19 upgrade SNAFU just to see if it helped. It seemed to make things worse so I moved it back to USB 2.0 after maybe a week of nothing but issues. That's my impression based on a lot of pain on 384.19 and trying USB 3.0 once again. I've learned my lesson. It's staying on USB2.0 port now period. Of course, YMMV. ;) Stay safe, stay alive.
 

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