UEFI & ZFS

[Thomas Laus]

> I've observed the slowness only on the local console, I haven't tested
> the seriel console. Put the FreeBSD legcay installation usb stick into
> the box, select it as boot device and watch the cursor spinning for
> about 10 minutens until the kernel boots. Do the same with an UEFI
> installation stick and it's a matter of seconds... 
> 
> I've seen this on an Gigabyte GA-Z170XP-SLI with a Core i7 6700k and on
> two Supermicro X11SBA-LN4F based machines with Skylake Xeon CPUs. There
> are several other reports of slow boot on Skylake CPUs on the net. In
> the thread mentioned below some changes in the hardware, the firmware 
> or somewhere else were suspected. I didn't even try to debug it,instead
> I went with the UEFI loader.
>
Yamagi:

My experience is the same as yours, but only with the combination of Legacy 
BIOS and ZFS installation.  UEFI loading of a ZFS filesystem is also a matter 
of seconds.  So is a Legacy/GPT/UFS installation.  I only see this on my i5 
Skylake when I perform a non-UEFI instalation using the ZFS filesystem.  I 
get a rapid boot with both OpenBSD 5.8 and using a MSDOS 6.22 USB floppy.  I 
have seen some patches posted to this list for testing.  I'll report back 
with my results.  I can't use UEFI because this will be a XEN server and UEFI 
support is not in the XEN kernel yet.

Tom

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