Norco & Adaptec 72405 - Mixing SAS & SATA

Krobar

Member
Aug 25, 2012
54
10
8
Hi All,

I need some new drives for my 24 bay Norco setup and it seems the SAS drive variants are cheaper. The backplanes apparently support SAS & SATA as does the Adaptec. I would initially be adding just 4 SAS drives so they would all be on one backplane card. Are there any compatibility or usage issues I should be aware of with using SAS drives? Do SAS drives generally power-down and work with power management? (Some SATA drive models refuse to power down in my setup but most do) Can SATA & SAS be mixed on the same backplane in future? If the drives are dual port does the second port just not get used?
 

llowrey

Active Member
Feb 26, 2018
105
73
28
I have a 20 bay and a 24 bay Norco chassis with mixed SAS and SATA devices and an Adaptec 72405 (24 port) and a 71605 (16 port). I have not experienced any issues mixing SAS and SATA.

On the power management front, the Adaptec firmware seems to try to keep the drives spinning at all times. Whenever I send a spin-down command to either the SAS or the SATA drives, the drives will spin down then, in less than a minute, will spin back up. Further, whenever I change the power policy settings for the SAS drives... the changes revert back to full power settings. I assume the controller is responsible for this behavior but I have not found any BIOS or driver settings to disable it. When I use one of my LSI controllers (eg 3008), I am able to manage power for the SAS drives just as expected... but not the SATA drives.

The only controllers I have had good power control luck with were junky Highpoint cards with Marvell chips. They actually served me very well until their PCIe2 interfaces made them impractical.

Beware that SAS drives seem to draw more heavily on 5V than SATA drives. I had to go to great lengths to feed the Norco backplanes with parallel feeds direct from the PS in order to avoid 5V brownouts.
 

kapone

Well-Known Member
May 23, 2015
1,046
620
113
I have never had disk power management issues with Adaptec cards (7 series or newer) and I use a lot of them. There's some edge cases, where a disk firmware doesn't play well with the card, but it's rare. Keep in mind:

- An Adaptec card will and can power down an entire array if you tell it to.
- If the card has been configured as RAID+Expose RAW (or as an HBA), and you're exposing RAW disks to the OS, the card has nothing to do with spinning down drives. It is up to the OS.
- Disk firmware(s) suck, especially if buying from fleabay. You have no idea what firmware there is on the disk and what it's configured for. And more often than not, it may be very very difficult, if not impossible, to change the disk firmware.