External USB drive causes one core to pin at ~100% wait time.

[TonyBucci]

I deployed (3) new 6.1 nodes and neglected to remove the install media from the 3rd one when I was done, the third node also has (2) virtual disks on its dell raid controller. That same third node was having weird web GUI issues like the second VD storage would disappear or the node and storages would have grey question marks before it was clustered. a reboot would stop the ~100% wait time for less than an hour or so and it would return on a different core, I ended up solving the issue remotely by disabling the USB ports in the BIOS and letting it boot back up. I didn't do much digging into logs since we suspected the USB drive and tried disabling the ports as a first step. I was also having issues with the pvs and lvs commands before the USB ports were disabled. is this a known issue, or is there something I should look at?

 

[apoc]

USB 2.0 and earlier are not DMA capable. This means that all I/O needs to run through a CPU and this results in a high load. Typically, when experiencing traffic, that was 100% load on one core (as you described it).
What I find weird is the fact, that you don't mention any I/O traffic in this situation...
Defective USB devices may trigger some odd behavior, but I only have seen such behavior on old USB ports / devices which were running at their maximum transfer rate.
HTH

I deployed (3) new 6.1 nodes and neglected to remove the install media from the 3rd one when I was done, the third node also has (2) virtual disks on its dell raid controller. That same third node was having weird web GUI issues like the second VD storage would disappear or the node and storages would have grey question marks before it was clustered. a reboot would stop the ~100% wait time for less than an hour or so and it would return on a different core, I ended up solving the issue remotely by disabling the USB ports in the BIOS and letting it boot back up. I didn't do much digging into logs since we suspected the USB drive and tried disabling the ports as a first step. I was also having issues with the pvs and lvs commands before the USB ports were disabled. is this a known issue, or is there something I should look at?