booting from raidz works, kind of

I finally got around testing ZFS-Root with RaidZ. As long as the root-filesystem is located in the top-level filesystem of the pool, everything works! So booting from RaidZ is possible in FreeBSD and manageBE/create-zfsboot-gpt_livecd.sh supports doing exactly this.

Only problem is, putting the root-filesystem in a sub-level filesystem, as I do it for manageBE, results in a ZFS: out of temporary buffer space when booting. There are some discussions on the freebsd-current mailinglist about booting from raidz configurations but until now, nothing substential has been commited. So I see booting from raidz as experimental for now.

UPDATE: I had some time today to track the ZFS: out of temporary buffer space error when booting from raidz and having the rootfs in a sub-level filesystem. Taking a look at zfs_alloc_temp() in  src/sys/boot/zfs/zfsimpl.c, which prints this error message, and going from that to zio_read(), I figured that this will only be triggered if compression for the rootfs is turned on. A quick test confirmed my assumption! So I will turn off the compression for now and file a bug!