ZFS on hardware RAID5

[Mtux]

Hi folks,
this is my first post, so first of all thank you all for FreeNas!

Here comes the question: I know that hw raid is deprecated in favour of RAIDZ(2) setups, but... I have a computer with a single sata port that doesn't support port multipliers, nevertheless I would like to attach an external 5 bay enclosure. Since I cannot use jbod (it would not be seen as 5 disk without port moltiplication capabilities) I was thinking of using the RAID5 option provided by the enclosure, in order to have a "single" big drive exposed to the pc. On top of that I would then make a zpool with copies=2 to have also integrity check.
If my reasoning is correct, this way I would be protected against disk failures by the hardware raid controller (and ZFS wouldn't even know that a disk is gone) plus data integrity check from ZFS, is it correct? Would there be any disadvantage?

Thank you,
Marco

 

[matthewowen01]

performance may be an issue though. you've got 2 competing structures.


do you have a PCIe slot? a 4 port or 8 port controller would be much preferred.

 

[Mtux]

Unfortunately I don't have any expansion slot available, that would have been perfect.
The fact is that I wanted to modify one of the internal sata port of a 2010 mac mini to have a file server that idles below 10 watts (not counting discs).
Seems that I will have to find another hardware solution...

Thank you,
Marco