On Tue, Jun 25, 2013 at 12:14:29PM +1000, Russell Coker wrote:
On Tue, 25 Jun 2013, Craig Sanders <cas@taz.net.au> wrote:
hence, if you want RAIDZ2 with four data disks, then 4 SAS data + 1 SAS parity + 1 SATA parity would achieve that.
Does RAID-Z allow you to designate parity disks?
no, in fact it stripes parity/checksum-metadata across all drives same as it does for actual data. my example was more notional, to illustrate the point, than a literal description of how it works in practice.
I thought it did more of a RAID-5 thing than a RAID-4 thing. Anyway I wouldn't recommend that on a HP server as SATA disks are really slow. It seems as if HP was deliberately making them slow to drive sales of expensive SAS disks.
ok, that's a really good reason not to use the SATA port with the zpool. with decent speed SATA ports, though, it would be worthwhile. craig -- craig sanders <cas@taz.net.au> BOFH excuse #360: Your parity check is overdrawn and you're out of cache.