ZFS Recommendations for a new server

[Warren Block]

On Fri, 30 May 2014, Matthew Seaman wrote:

> On 05/30/14 16:11, Alejandro Imass wrote:
>> The new server has a 2 x 1TB RE4 3ware 9650SE RAID and I have friends that
>> tell me is actually better to use ZFS RAID instead of HW RAID1. Is this
>> true? Why so?
>
> I recently had a similar setup using an old 3ware RAID card, which we
> upgraded to 4TB drives .... and then had to ditch the 3ware card and
> replace it with a LSI HBA because the 3ware card didn't recognise
> anything beyond the first 2TB or the drives.
>
> Yes, you want to use ZFS RAID rather than putting ZFS onto a single
> virtual drive presented by your RAID controller.  ZFS does all the
> resilience and patrol read^W^Wzpool scrubbing and disk IO caching and
> stuff using your system's main RAM and CPUs which are generally a lot
> more capable than any RAID controller.  Plus ZFS does it better --
> 'punctured stripe' is not something that happens to ZFS for instance.

Another way to explain this is that ZFS makes the computer itself into a 
RAID controller, only with more resources and much more development of 
the "firmware".