[mtdblock3] CPU usage every 10 seconds

[akb]

I noticed one day watching the CPU graph for my AC88u that it would spike to 50-80% every 10 seconds. I did a top and saw that [mtdblock3] was the one doing it. Any help on what this means for me. Reboots and firmware upgrades do not change the behavior.

 

[akb]

what does rootfs do that needs to be ran every 10 seconds for my cpu spike to happen?

dev: size erasesize name
mtd0: 00080000 00020000 "boot"
mtd1: 00180000 00020000 "nvram"
mtd2: 03e00000 00020000 "linux"
mtd3: 03c498f0 00020000 "rootfs"
mtd4: 04000000 00020000 "brcmnand"

 

[RMerlin]

what does rootfs do that needs to be ran every 10 seconds for my cpu spike to happen?

dev: size erasesize name
mtd0: 00080000 00020000 "boot"
mtd1: 00180000 00020000 "nvram"
mtd2: 03e00000 00020000 "linux"
mtd3: 03c498f0 00020000 "rootfs"
mtd4: 04000000 00020000 "brcmnand"

rootfs contains the firmware. It probably means you have a program that loads something from the firmware partition every 10 secs, can be a program that gets restarted every 10 secs for example.

 

[akb]

rootfs contains the firmware. It probably means you have a program that loads something from the firmware partition every 10 secs, can be a program that gets restarted every 10 secs for example.

Only have absolutions running, I turned it off and still have the spikes. Are there any commands which can narrow down what is being read from rootfs or who the source is. Non of my linux commands that I know like lsof work.

 

[RMerlin]

If you have Entware setup, you can install "lsof" to help troubleshooting things:

opkg install lsof

Otherwise, take a look at the "top" and "ps" output. Syslog might also contain clues.

 

[akb]

Thanks for showing that entware can install lsof, I was able to narrow down the culprit to "lighttpd-monitor" it was constantly using mtd3, and once killed, stopped it.

 

[RMerlin]

Thanks for showing that entware can install lsof, I was able to narrow down the culprit to "lighttpd-monitor" it was constantly using mtd3, and once killed, stopped it.

That program is part of AiCloud. Do you use AiCloud?

 

[akb]

That program is part of AiCloud. Do you use AiCloud?

I used to, but now I have turned it off. Thanks for your help RMerlin, and I love all your updates for all my asus products.

 

[DX81]

Thanks for showing that entware can install lsof, I was able to narrow down the culprit to "lighttpd-monitor" it was constantly using mtd3, and once killed, stopped it.

I'm having the same issue after tracking down the process that is causing the CPU to spike - kinda still new to linux so could you share what commands you used to shutdown "lighttpd-monitor" and/or AIcloud?

Thanks in advance!

 

[Makaveli]

I'm having the same issue after tracking down the process that is causing the CPU to spike - kinda still new to linux so could you share what commands you used to shutdown "lighttpd-monitor" and/or AIcloud?

Thanks in advance!

You can turn off AI cloud in the GUI of the router.

And nice necro this thread is almost 3 years old.

 

[DX81]

You can turn off AI cloud in the GUI of the router.

And nice necro this thread is almost 3 years old.

Unfortunately disabling AI Cloud via the GUI doesn’t terminate the same process responsible for the high CPU usage tracked down by the previous user as responsible - AI Cloud and all of its features were already turned off to begin with.

I assumed it required “lighttpd-monitor" to be disabled/killed manually as was suggested.

And yeah - looks like three years later people are still facing the same very issue even on the latest firmware.

 

[ColinTaylor]

And yeah - looks like three years later people are still facing the same very issue even on the latest firmware.

Are you sure it's the same problem/process? Apart from the OP I don't remember anyone else ever reporting this problem. (and people are overly sensitive about their CPU usage)

 

[DX81]

Are you sure it's the same problem/process? Apart from the OP I don't remember anyone else ever reporting this problem. (and people are overly sensitive about their CPU usage)

I don’t for sure..

trying to install and use lsof results in the install command returning a package size mismatch from the default entware site ( see below)

however it’s more than just being ‘sensative’ to high CPU usage.

When the high cpu usage occurs it takes both dual cores to 100% and results in page timeouts for regular website requests because I believe the router isn’t passing on DNS requests while whatever process is causing then CPU spike

What is certain is that the same main process “mtdblock3” is the what is causing the issue verified by using the top command. Without lsof I don’t know any other way to determine what is calling and is responsible for imitating mtdblock3 in the first place.

Any actual advice or ideas of what to try would be really helpful.

admin@RT-AC88U:/tmp/home/root# opkg install lsof
Installing lsof (4.91-1) to root...
Downloading http://bin.entware.net/armv7sf-k2.6/lsof_4.91-1_armv7-2.6.ipk
Collected errors:
* opkg_install_pkg: Package size mismatch: lsof is 63434 bytes, expecting 63495 bytes
* opkg_install_cmd: Cannot install package lsof.

 

[ColinTaylor]

however it’s more than just being ‘sensative’ to high CPU usage.

When the high cpu usage occurs it takes both dual cores to 100% and results in page timeouts for regular website requests because I believe the router isn’t passing on DNS requests while whatever process is causing then CPU spike

What I meant by "sensitive" is that the geeks on this site watch their router's CPU usage like a hawk and if they saw they same symptoms as you describe they would be very vocal about it.

What is certain is that the same main process “mtdblock3” is the what is causing the issue verified by using the top command. Without lsof I don’t know any other way to determine what is calling and is responsible for imitating mtdblock3 in the first place.

Unfortunately, as described above mtdblock3 doesn't necessarily mean it's anything to do with lighttpd-monitor. All that means is that it is reading something from the firmware's operating system - but it could be anything.

What command did you use to install Entware?

 

[DX81]

What I meant by "sensitive" is that the geeks on this site watch their router's CPU usage like a hawk and if they saw they same symptoms as you describe they would be very vocal about it.

ah, right - that’s true. I’m not sure if it’s some combination of using diversion/ab-solution and skynet or just my particular setup

I’m wondering if it’s a USB drive issue as research about mtdblock3 seems to loosely indicate it’s writing to the partition excessively as the cause of the cpu usage

in terms of installing lsof, just used the default style I found worked for others:

opkg install lsof

 

[ColinTaylor]

Can you log into the router and confirm your partition layout with the following command:

cat /proc/mtd

And try this:

opkg update
opkg install lsof

 

[DX81]

Can you log into the router and confirm your partition layout with the following command:

cat /proc/mtd

Thanks heaps for the help and thoughts!

Below is the output of what the partition layout is - does that look right to you?

admin@RT-AC88U:/tmp/home/root# cat /proc/mtd
dev: size erasesize name

mtd0: 00080000 00020000 "boot"
mtd1: 00180000 00020000 "nvram"
mtd2: 03e00000 00020000 "linux"
mtd3: 03c3d50c 00020000 "rootfs"
mtd4: 04000000 00020000 "brcmnand"

 

[DX81]

opkg update
opkg install lsof[/CODE]

Oh wow! completely overlooked updating opkg (!) that worked! )

Just trying to decipher the output from lsof and see what I can make out of it - unfortunately the CPU usage spikes are somewhat random and not fully sure what I should be looking out for with lsof

Really appreciate the kind help so far so very much

 

[d3f]

Thanks for showing that entware can install lsof, I was able to narrow down the culprit to "lighttpd-monitor" it was constantly using mtd3, and once killed, stopped it.

what was the command?

 

[zizzyzizzy]

@Makaveli Another necro post here, another three years later. Can you guess why? Yup, this is STILL a problem in 2023, and this is the first post that comes up on a Google search. Condescending comments about necro posting relevant and current information are not appreciated or needed in a help forum.

Anyway, this is still an issue years later. I'm about ready to throw this Asus router out the window because it keeps grinding to a halt. The most likely suspect is mtdblock3, which is eating up 99% of the CPU and causing a load of over 32 on my router. Like the other poster, I don't need or want AI Cloud, which is why it's disabled and yet still bricking my router. Nothing has changed on this router in months.

Does anyone have any suggestions about this issue or comments as to why it's still in issue in 2023? Is there any way to rename or remove the file being run for no reason?

**UPDATE** I updated the firmware with a release that came out two weeks ago. It's been 30 minutes with no high CPU or high load issues. I would still like to know why mtdblock3 is running in the first place and how to prevent this from happening again.