Is CTL multi-threaded?

[Thomymaster]

Hi

I'm just unsure if CTL/ISCSI target is multi-threaded in the lates 9.3 FreeNAS?

If i e.g. suspend my VMs which are hosted by my ESXi, i see (with top) a CPU utilization of 50% but not more.
Its not getting more if i suspend/resume multiple VMs at a time.


Cheers Thomy

 

[cyberjock]

Is ctl using 50% or is it something else?

Does your CPU do hyperthreading? (What CPU are you using?)

 

[Thomymaster]

Hi

I use an Intel XEON E5345 (quad core 2,33GHz) in my FreeNAS box. The CPU usage when doing ISCSI gets stuck at 50%

 

[cyberjock]

I'm wondering if you are bottlenecked by the FSB on that CPU and it happens to put you at about 50%. From what I've heard ctl does as many threads as you have cores so I tend to think its a coincidence.

But I hate coincidences.

Check this out though...
# sysctl kern.cam.ctl.worker_threads

and
# sysctl kern.cam.block.num_threads

Mine is 2 and 14 respectively.

To be honest, I would do some serious research on those before changing them, but you *might* find that changing them helps.

Personally, I try to stick to (and recommend) the defaults unless I *fully* understand the implications of the change or I'm getting the recommendations from a higher power than myself. So often you don't know all the implications, even if you think you do.

I *definitely* wouldn't change it right now if the data you are manipulating isn't backed up. You also might find out if you change it that it takes a reboot to actually take effect.

Hope this helps.