FreeBSD 10.3 slow boot on Supermicro X11SSW-F

[Miroslav Lachman]

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?


Miroslav Lachman