[OpenIndiana-discuss] hardware specs for illumos storage/virtualization server

[Jim Klimov]

On 2012-11-19 04:14, Paul B. Henson wrote:
>> On another hand, especially given the expected lower performance of
>> these disks and overall large volume, I'd go with raidz3 to be on
>> the safer side. But my wife turned down such a budget a few times ;)
>
> Ouch. The amount of "wasted" storage for raidz2 already hurts bad enough
> :).

Well, if you consider how many days it may take to just scrub your pool,
and likely more than that to resilver a disk, you might begin to want
an extra disk of protection. The ZFS/Fishworks guys (sorry, forgot who -
but they are on the lists) had nice blog posts with mathematical theory
and practical numbers to display the interconnection of the bit error
rates, disk sizes, IO speeds and reconstruction times to provide rules
of thumb - how many redundancy disks are needed so that this is not all
in vain. My general takeaway from the article was that around 3tb+ we
need to incline towards raidz3 or three-(four-) way mirrors, and higher
redundancies may be in order when larger disks hit the market.

//Jim