Re: NetBSD 9.2 AMD64: Starts first DOMU and disk performance drops by about 100x?

[Johan Stenstam <johani%johani.org@localhost>]

Hi Brian,

> Hello.  Since you've been using the machine for a while and since you disconnect it from
> power for long periods of time while you travel, I wonder if some of the BIOS settings got lost
> during one of those travel sessions?

Umm, well, not that long really. Typically the server is connected unless I’m travelling and it will be disconnected, put in its case during a flight and the unpacked and reconnected. So it is very rare that it is offline more than a maximum of 24h.

> Specifically, I'm wondering if the SATA controllers
> switched out of ahci mode and back into ide mode?  Seems like that could trigger the behavior
> you're seeing.  Not sure why starting  a domU would trigger the problem and not sooner, but
> that's an initial thought.

Umm.

> Since the problem seems to trigger once a domU starts, it might also be one of the CPU
> settings in the BIOS, say the virtual settings?  

Urg. That’s unpleasant, never even thought of that.

So this box is a Shuttle (a well-known “luggable” server) and it has an annoying quirk. The BIOS doesn’t want to talk to the USB-keyboard during startup. Once NetBSD boots everything is fine, but prior to NetBSD it is very difficult to break into the BIOS. Usually I *can* break into the BIOS, but it takes something like several dozen attempts. I’ll try that as soon as possible, but if I succeed what do you suggest that I look for?

Regards,
Johan