SATA and SAS. Can I mix? Should I go with SAS?

Notice: Page may contain affiliate links for which we may earn a small commission through services like Amazon Affiliates or Skimlinks.

PigLover

Moderator
Jan 26, 2011
3,184
1,545
113
ok - but if that is true then you are out of spec just for the SATA drives alone (i.e., if your net effective cable length is over 1m then the SATA drives are not guaranteed to work even if you are not mixing in SAS drives).
 

jasonlitka

Member
Jun 24, 2015
43
15
8
41
ok - but if that is true then you are out of spec just for the SATA drives alone (i.e., if your net effective cable length is over 1m then the SATA drives are not guaranteed to work even if you are not mixing in SAS drives).
Oh, absolutely.
 

whitey

Moderator
Jun 30, 2014
2,766
868
113
41
I have that configuration in use in a few places and never ran into issues with it. Wonder which systems are more/less tolerant of that configuration.
I concur, heard the same but I do it, not saying you should but I have never experienced any issues. Mostly sata here but I'd take sas anyday over sata in a large array if $ was not an option and intend to replace my sata w/ sas drives 'someday'...especially because I come off LSI 2008 to Intel sas expander and than to my backplanes/disks.

I live in the risky/fast lane apparently.
 
  • Like
Reactions: coolrunnings82

Aluminum

Active Member
Sep 7, 2012
431
46
28
My understanding (with LSI 2k8 and newer) is that you can mix them on the same controller but you do not want to mix them on the same 4 port connector, passive backplanes same idea. This effectively means to never mix on any expanders as well since ultimately those drives all live in the same 'lan'. (SAS is technically another network)

Also some expanders / active backplanes just plain suck at tunneling sata without glitches and should only be used with SAS drives, but I believe the LSI SAS2 expanders with current firmware should be ok with sata as long as not mixed?
 

andrewbedia

Active Member
Jan 11, 2013
698
247
43
I've ran RE SAS drives and random SATA drives in the same HP StorageWorks MSA60. Never had any problems whatsoever.
 

Terry Kennedy

Well-Known Member
Jun 25, 2015
1,140
594
113
New York City
www.glaver.org
I have heard this for years. What is the reasoning behind it? Does SAS handle things better if a drive goes nuts and keep the storage system stable or something?
The most common issue when using SATA drives with a SAS backplane / controller is problems with SAS expanders. If a SATA drive "loses its marbles", the other drives on that same expander may drop offline. This will cause RAID to mark multiple drives as offline, potentially corrupting the RAID volume. In systems without expanders, I've had no problems using generic SATA drives, though I normally use "RAID edition" type drives. If I had to use generic non-RE drives, I'd use a host-based solution like ZFS, rather than relying on a RAID controller to "do the right thing".
 
  • Like
Reactions: Diavuno

Razvan

Member
Aug 4, 2015
31
4
8
Also related to this -- given a LSI SAS 9207-4i4e controller with both internal and external ports and a NSC-800 case (dumb backplane):

- Is there going to be a problem having sata drives on the internal port and a sas tape to the external one?

- Are there any advantages (less overhead, better signaling/reliability) for using nearline sas disks over sata in this setup? The dualpath doesn't count, given the construction of this particular backplane.
 

Diavuno

Active Member
The most common issue when using SATA drives with a SAS backplane / controller is problems with SAS expanders. If a SATA drive "loses its marbles", the other drives on that same expander may drop offline. This will cause RAID to mark multiple drives as offline, potentially corrupting the RAID volume. In systems without expanders, I've had no problems using generic SATA drives, though I normally use "RAID edition" type drives. If I had to use generic non-RE drives, I'd use a host-based solution like ZFS, rather than relying on a RAID controller to "do the right thing".
yeah I know.... lost one drive in a Raid volume... my 3ware kicked 2 other members.
 

juhan

New Member
Mar 28, 2021
1
0
1
I'm a bit confused. I'm sure I saw in the documentation for my Supermicro 846 storage server that it was OK to mix SATA and SAS drives. The RAID controller is an LSI 9271-8i, with upgraded firmware, so I can run bigger 8TB SAS drives in JBOD mode and do SW RAID using ZFS on Ubuntu Linux. I have only boot disk(s) setup with RAID1 HW mirroring by the controller. All other disks are managed as JBOD. Most of the disks are SAS, but I have a few SATA, mostly to test whether it is possible to mix them, and it seems to work. Are we saying that it "barely works" (if nothing goes wrong?)? I have not tried to verify any voltages in the enclosure. I prefer to run SAS drives, but have some SATA: better on-line than on the shelf?
p.s. I generally prefer SW RAID, in case HW "blows up" (and no spare or replacement available), then SW RAID can be moved almost anywhere.