Pointer to info on migrating from UFS2 -> ZFS?

[Adam Vande More]

On Tue, Apr 22, 2014 at 5:25 PM, David Wolfskill <david at catwhisker.org>wrote:

> I appreciate the responses, but I seem to have failed to communicate at
> least a couple of fairly important aspects of what I'm trying to do.
> So....
>
> On Mon, Apr 21, 2014 at 06:40:05PM -0700, Louis Kowolowski wrote:
> > I?d probably suggest a couple things:
> > * VirtualBox (or equiv) for setting up test environments that are easy
> to create and destroy. For all the beginning stuff I can think of, you
> should be able to do just fine with a virtual environment. VMs with a half
> dozen virtual disks that are 2G ea come in handy with playing with ZFS.
>
> I have existing hardware -- several instantiations of it, including a
> couple of test machines.  I am trying to find out if the use of ZFS (vs.
> UFS2+SU) on the existing hardware will provide a performance advantage
> (and if so, how much, as switching from UFS2 to ZFS is going to be
> extremely painful).
>

It's very difficult to make any detailed concise comment since we know
virtually nothing about your hw or workload.  What do you need?  More iops?
 Then use a ZIL (maybe even a battery backed DDR drive) to increase writes,
and lots of RAM and cache device to increase read speed.  When I had this
setup, diskinfo run on VM's backed by ZVOL's would reflect SSD, not 7200
spinning media speeds.

Also things like transparent compression can help certain workloads
tremendously.  If you're dealing with 99% text data by compressing the data
you effectively drastically lower the iops needed to work the data and
off-load the work to the CPU's which are obvious a lot faster than disk.

There are also a lot of different RAID(z) qualities so care should be taken
when choosing layouts.



-- 
Adam