Odd CPU usage after 9.3 install

[Jailer]

Took some screen shots of some odd behavior I've had since I installed 9.3 beta. Seems I have a constant recurring small amount of CPU usage. Looks like whatever is causing it is accessing the hard drives and network as well. I'm not even sure where to start looking to figure out what's causing this either.

Hardware (just a test rig)
Motherboard Gigbyte GA-P35-DS3L
CPU Core 2 Duo E7200
8GB non ECC ram
4-500 GB hardrives RAIDz

The screenshots:

 

[cyberjock]

If I had to guess I'd say that the normal tasks like auto-replication and auto-snapshotting are causing enough of a workload for your system to cause deflection of your CPU usage. Virtually all CPUs that have FSBs are bottlenecked by the FSB. They are very poor choices for FreeNAS as a result, and you do have a FSB. I used to use that CPU and board combo, and I think I sold it in 2008 used to a friend. In any case, your hardware is quite hold and aside from it being a test box I wouldn't use it for much more.

You could say that this is an excellent indicator of why test machines should match real-world usage cases and not be spare hardware. Otherwise you might see bad behavior as a result that simply doesn't exist in real-world usage. ;)

 

[Jailer]

The remainder of my new hardware will be delivered tomorrow so that issue should be resolved soon. ;)

https://forums.freenas.org/index.php?threads/pulled-the-trigger-today.24688/

Odd that it didn't display this behavior when I was running 9.2.8 and I don't have replication or snapshots turned on then or now. Any clue where to look to see whats causing it?

 

[cyberjock]

Well, 9.3 has changed so many things about 9.3 we can't even remember them all.

You don't have to have replication or shapshots to have the autoreplicator run. It checks every minute all day and night and if it has nothing to do it quits.

You could start looking in TOP to see what is going on.

 

[Jailer]

Well it looks like it's python. It shows a spike of around 15% CPU use in the system processes about every minute. But again why now when it never did it before the update to 9.3?

 

[fracai]

The following command will tell you exactly what that python task is doing. It'd be a good idea to check the running processes first to make sure you're using the appropriate PID.

Code:

ps -axww -p 84383

 

[cyberjock]

The autoreplicator is python and runs every minute, so that tends to confirm my suspicions.

As for the cause, I can't begin to speculate because there are too many variables at play. To be honest, the answer doesn't really matter particularly much since the fix is simple.. get better hardware. There's not going to be a "solution" for your problem that will be resolved in software. At least, I doubt the devs will care about it enough to see if there is a problem since the problem is almost squarely due to the hardware you are using. If we were seeing it on recent hardware then we'd have a problem that would warrant investigating.

 

[RobertT]

My hardware is not old and is basically the same stuff that is in the mini. I see very similar spikes. Looks like it is autosnap.py and alert.py every 1 minute.

Code:

root  60798  0.0  0.1  71260  12400 ??  Rs  12:59PM  0:00.11 /usr/local/bin/python /usr/local/www/freenasUI/tools/autosnap.py (python2.7)
root  60799  0.0  0.1  67228  12984 ??  Rs  12:59PM  0:00.12 /usr/local/bin/python /usr/local/www/freenasUI/tools/alert.py (python2.7)
root  60798  9.9  0.2 135520  38812 ??  Rs  12:59PM  0:01.10 /usr/local/bin/python /usr/local/www/freenasUI/tools/autosnap.py (python2.7)
root  60799  9.9  0.2 135520  38732 ??  Rs  12:59PM  0:01.10 /usr/local/bin/python /usr/local/www/freenasUI/tools/alert.py (python2.7)
root  60799  18.3  0.3 141408  45424 ??  Rs  12:59PM  0:02.12 /usr/local/bin/python /usr/local/www/freenasUI/tools/alert.py (python2.7)
root  60798  18.2  0.3 141664  45500 ??  Rs  12:59PM  0:02.07 /usr/local/bin/python /usr/local/www/freenasUI/tools/autosnap.py (python2.7)
root  60798  25.6  0.4 184808  60832 ??  Rs  12:59PM  0:03.12 /usr/local/bin/python /usr/local/www/freenasUI/tools/autosnap.py (python2.7)
root  60799  25.6  0.4 184808  60748 ??  Rs  12:59PM  0:03.11 /usr/local/bin/python /usr/local/www/freenasUI/tools/alert.py (python2.7)
root  61377  0.0  0.1  91336  18908 ??  Rs  1:00PM  0:00.29 /usr/local/bin/python /usr/local/www/freenasUI/tools/autosnap.py (python2.7)
root  61379  0.0  0.1  89212  18708 ??  Rs  1:00PM  0:00.29 /usr/local/bin/python /usr/local/www/freenasUI/tools/alert.py (python2.7)
root  61377  11.4  0.2 136288  39868 ??  Rs  1:00PM  0:01.28 /usr/local/bin/python /usr/local/www/freenasUI/tools/autosnap.py (python2.7)
root  61379  11.3  0.2 136288  39764 ??  Rs  1:00PM  0:01.28 /usr/local/bin/python /usr/local/www/freenasUI/tools/alert.py (python2.7)
root  61377  19.5  0.3 142688  46632 ??  Rs  1:00PM  0:02.27 /usr/local/bin/python /usr/local/www/freenasUI/tools/autosnap.py (python2.7)
root  61379  19.5  0.3 142688  46564 ??  Rs  1:00PM  0:02.29 /usr/local/bin/python /usr/local/www/freenasUI/tools/alert.py (python2.7)
root  61377  26.8  0.4 190184  63928 ??  Rs  1:00PM  0:03.28 /usr/local/bin/python /usr/local/www/freenasUI/tools/autosnap.py (python2.7)
root  61379  26.7  0.4 190440  64328 ??  Rs  1:00PM  0:03.28 /usr/local/bin/python /usr/local/www/freenasUI/tools/alert.py (python2.7)