UFS vs. ZFS inside bhyve hosted on ZFS

[Paul Vixie]

Russell L. Carter wrote:
> ... I have two bhyve VMs configured
> identically, both running r297047, each configured with 15G of RAM and
> 3 cpus, verified by examining 'sysctl hw' from within the running
> guest. One has the default ZFS install, the other UFS. However,
>
> # cd /usr/src && make buildworld -j <anything>
>
> after 15 minutes or so freezes the -current-UFS guest with the
> following console output:
>
> root at vm1:~ # ahcich0: Timeout on slot 29 port 0
> ahcich0: is 00000008 cs 00000000 ss 00000000 rs bfffffff tfd 50 serr
> 00000000 cmd 0001dd17
> (ada0:ahcich0:0:0:0): WRITE_FPDMA_QUEUED. ACB: 61 40 70 dc 3a 40 00 00
> 00 00 00 00
> (ada0:ahcich0:0:0:0): CAM status: Command timeout
> (ada0:ahcich0:0:0:0): Retrying command

two questions:

why ada rather than vtblk?

is the host's backing store made with 'zfs create -V', or is it 'truncate'?

-- 
P Vixie