SATA or SAS

[ntcue]

Hi folks,

I've got an Ubuntu machine here with 12 HDDs and 1 SSD for the system itself. In the future there will be added more disks, maybe up to 14 HDDs.

Because one of my current SATA-controller fails after standby I want to replace it with something better and more reliable. Ubuntu recognizes it as "Marvell Technology Group Ltd. 88SE9230 PCIe SATA 6Gb/s Controller (rev 11)". The other controller is a "Marvell Technology Group Ltd. Device 9215 (rev 11)" which runs fine.

 

Now I am curious if there is any advantage between a 8x SATA controller card or any SAS controller card with a adapter cable from SAS to 4x SATA or similar. As I understand SAS is fully compatible to SATA and you simply buy a cable from SAS SFF-8087 > 4 x SATA or whatever physical plug is on that controller card. Am I right with that? It seems that SAS controller cards a way cheaper than SATA controller cards and so I could save some money too. But are they compatible to Linux, is there something I have to look for?

 

Thank you!

[Electronics Wizardy]

Normally the sas controllers are more reliable and have better os support, and cost about the same so no reason not use the sas controllers. SAS also gives them more features, like letting expanders to be used

[paddy-stone]

You should be Ok with LSI 9211-8i cards or similar,,, these are my preference too, You will need a pci-e 4x slot available IIRC though, so bear that in mind. I didn't have any problem using in windows/freenas, and I think linux, but can't remember right now... my LSi card is flashed to IT mode for freenas to have direct access to the drives, you can get them pre-flashed to IT mode if needed.

[WereCatf]

Personally, I see no point in those SAS-controllers: those SATA-controllers are perfectly well supported under Linux and you don't need the more expensive SAS->SATA-cables. SAS can't even make the drives any faster, since it's the drives that are the bottleneck, not the controller.

[seagate_surfer]

The SATA may no be better regarding transfer rates than SAS because they are about the same, it is just that is common to see SAS in enterprise like system and not in regular consumer computers. 

[ntcue]

Just now, WereCatf said:

Personally, I see no point in those SAS-controllers: those SATA-controllers are perfectly well supported under Linux and you don't need the more expensive SAS->SATA-cables. SAS can't even make the drives any faster, since it's the drives that are the bottleneck, not the controller.

Yes, the drives are not fast enough to use the full potential of the controllers. So you think it makes no sense because the adapter cables + controller are more expensive than a SATA controller? Hm.

But as I pointed out not every SATA controller seems to be compatible with Linux. Or maybe it's an other issue. The 88SE9230 chipset seems not to work well. So I have to look for an other one.

I found theses:

• InLine 76617G 8 Port (one commenter mentions an issue with standby, so maybe not this one)
• MZHOU PCIe SATA Karte 6 Port (Marvell 88SE9215)
• DeLock PCI Express Karte, 10x SATA 6 Gb/s intern

Of course there are much more out there. Do you have some further suggestions?

[WereCatf]

3 minutes ago, seagate_surfer said:

it is just that is common to see SAS in enterprise like system and not in regular consumer computers. 

SAS just doesn't provide any benefit for consumers over SATA.

[WereCatf]

5 minutes ago, ntcue said:

The 88SE9230 chipset seems not to work well

It looks like the issue is because that chipset has some sort of a shitty RAID-implementation on it. I have several cards based on the 88SE9215 which lack any built-in RAID and they've been working for years without even the tiniest issue. I use software-RAID, because it's a lot more flexible and a lot more reliable, plus I get bitrot-protection as an added bonus as well.

[seagate_surfer]

6 minutes ago, WereCatf said:

SAS just doesn't provide any benefit for consumers over SATA.

Yeah, I know what you mean. You've got a point, there is more devices focused for enterprise environments with a SAS interfaces than what you can find in the consumer market if any. 

[WereCatf]

8 minutes ago, seagate_surfer said:

Yeah, I know what you mean. You've got a point, there is more devices focused for enterprise environments with a SAS interfaces than what you can find in the consumer market if any. 

It's a shame. I'd have plenty of use for an external 12-bay (or more) enclosure, but they're stupid expensive, since they're not consumer-stuff

[ntcue]

18 hours ago, WereCatf said:

It looks like the issue is because that chipset has some sort of a shitty RAID-implementation on it. I have several cards based on the 88SE9215 which lack any built-in RAID and they've been working for years without even the tiniest issue. I use software-RAID, because it's a lot more flexible and a lot more reliable, plus I get bitrot-protection as an added bonus as well.

I also use Software-RAID, so I don't need any hardware RAID controller functionality, just plain SATA controllers.

Your explanation sounds reasonable, which means the 9215 chipset should be good for me. I try to find out one without RAID controller functionality.