Is it possible to mix SATA and SAS drives on the same controller?
These are intended to be used these in server 2012 R2 software raid?
Is that a question? ;-)
Obviously not mixed in the same array but maybe on the same controller, depending
on how many disk controllers the server comes with.
SATA drives on a SAS controller / SAS hostadapter / SAS based RAID card should work just fine. You probably want to avoid port multipliers though because if a SATA drives dies then that might lock up the multiplier. If you just use direct connections then mixing them should be fine.
My original intention was a layout like this: 2 x SATA 250GB mirrored -
for Hyper-V partition 4 x SAS software Raid 1+0 - for virtual machines and
all data 1 x SATA - for backup purposes
Backups are good. But I recommend also storing backups off-line or at least elsewhere. This to prevent loss of both originals and backups in the case of fire, flooding, lightning strike, theft, ...
Problem is now it comes to ordering the hardware it seems there is some question as to whether it can support SATA and SAS at the same time.
It can. I am writing the answer from a desktop with a 3ware 9750 RAID card with both SAS and SATA drives attached to the same card.
FYI: Link to a similar question over on [SU], which was answered by a regular on [SF]. The same answer is true for software RAID. (In fact, if you are going to use SW based RAID and have a HW RAID card, then reflash the RAID card to a target/initiator mode).