boot from ZFS: which pool types use?

[Dmitry Morozovsky]

Dear colleagues,

I'm a bit stuck and possibly my google-fu sleeps somewhere, but I have 
inconsistent cases on what pool types can one use to boot contemporary 
(read: stable/9) FreeBSD from.

For example, I have many older servers with UFS /bootdisk and ZFS-on-root.  
While this is useable, it does not seem to be very consistent.

On the other hand, I have a couple of servers with ZFS-only config which uses 
complex raid10-like config on gpart disks, and they boot flawlessly, at lest 
till now.

Lastly, I'm now in process of setting up new server, and trying to do the same, 
configuring ZFS with 4 pairs of SAS, now have

Can't find /boot/zfsloader

I suppose from line 619 from sys/boot/i386/zfsboot/zfsboot.c

Configs are essentially the same, I double-check gpart bootcode and zpool.cache 
(while I still did not found the guide how to interprete its content; at least 
one of my ZFS servers successfully runs without it)

Any hints?  Are stripe-mirror configuration available for booting from (yes, I 
do remember that all, or at last enough for degraded use, disks should be 
exposed to BIOS by controller firmware, and it is usually constrained to 6 or 8 
disk devices)

Thanks!


-- 
Sincerely,
D.Marck                                     [DM5020, MCK-RIPE, DM3-RIPN]
[ FreeBSD committer:                                 marck at FreeBSD.org ]
------------------------------------------------------------------------
*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck at rinet.ru ***
------------------------------------------------------------------------