dandelion said:(gpt)zfsboot+loader and grub2 don't recognize zvols as disks/devices. And only grub supports chainloading disks. So, yeah, unless grub2 has a driver like the one it has for scsi/lvm/mdraid/etc it's currently not possible to boot from anything on top of a zvol be it ufs, zfs, ext2, msdosfs, etc.
OTOH, if you only need rootfs on zvol then it should be possible to use smth like
[cmd=]vfs.root.mountfrom="ufs:/dev/zvol/tank/blah"[/cmd]
but it won't work on zfs v15 and earlier as they require invoking zfs volinit before zvol devices in /dev become available. This can be worked around by mounting mfsroot and executing it first, though.
SirDice said:
This doesn't make sense.bendany said:I just want a root fs on zvol over zfs, which is a UFS filesystem.
bendany said:I know we can boot from zfs.
I just want a root fs on zvol over zfs, which is a UFS filesystem.
phoenix said:You mean: you want UFS for the / filesystem, on a ZVol (/dev/zvol/pool-name/volume-name).
dandelion said:(gpt)zfsboot+loader and grub2 don't recognize zvols as disks/devices. And only grub supports chainloading disks. So, yeah, unless grub2 has a driver like the one it has for scsi/lvm/mdraid/etc it's currently not possible to boot from anything on top of a zvol be it ufs, zfs, ext2, msdosfs, etc.
OTOH, if you only need rootfs on zvol then it should be possible to use smth like
[cmd=]vfs.root.mountfrom="ufs:/dev/zvol/tank/blah"[/cmd]
but it won't work on zfs v15 and earlier as they require invoking zfs volinit before zvol devices in /dev become available. This can be worked around by mounting mfsroot and executing it first, though.
phoenix said:Have a look at the ManageBE project, which adds selectable boot environments (similar to Solaris) to FreeBSD root-on-ZFS systems.