FreeBSD 10.3 slow boot on Supermicro X11SSW-F

[Jan Bramkamp]

On 28/06/16 15:59, Miroslav Lachman wrote:
> I installed FreeBSD 10.3 on brand new machine Supermicro X11SSW-F. It
> sits on top of 4x 1TB Samsung SSDs on ZFS RAIDZ2.
>
> The booting is painfully slow from BTX to menu to kernel loading.
> Progress indicated by \ | / - characters is changing by speed of 1
> character per 2 seconds.
> The whole boot process takes about 10 minutes.
>
> I found this blog post solving the same problem
> http://smyck.net/2016/06/15/freebsd-slow-zfs-bootloader/
>
> It seems there is some bug in loader in 10.3. If /boot/pmbr,
> /boot/gptzfsboot and /boot/zfsloader are replaced by files from
> 11-CURRENT snapshot (from
> ftp://ftp.freebsd.org/pub/FreeBSD/snapshots/amd64/11.0-CURRENT/base.txz)
> the booting speed is back to normal.
>
> Is it know problem? What was changed in loader between 10.3 and 11?

The bootloader disk caching. The old code doesn't work (well) on modern 
UEFI implementations. You can get acceptable bootloader performance with 
the FreeBSD 10.3 EFI bootloader on such boards. Even the UEFI install 
images contain fallback BIOS bootcode and some boards prefer the old 
BIOS bootcode. On such boards you have to suffer through the slow boot 
process once to install FreeBSD.