UFS vs. ZFS inside bhyve hosted on ZFS

[Russell L. Carter]

On 03/19/16 20:13, Paul Vixie wrote:
>
>
> 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?

No idea.  I chose the default UFS selection in the iso installer.
Happy to change it to something better.

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

 From https://github.com/pr1ntf/iohyve/blob/master/iohyve:

zfs create -V $size -o volmode=dev $pool/iohyve/$name/disk0

where $size is 32G.  Neither side of (host/guest) looks even slightly
cramped after the fact.

Best,
Russell