Multiply your problems with SATA Port Multipliers and cheap SATA controllers

[jgreco]

jgreco submitted a new resource:

Multiply your problems with SATA Port Multipliers and cheap SATA controllers - Bad technology, multiplied by more evil

In the last year or two, we've had a resurgence of users asking about SATA Port Multipliers and cheap SATA controllers.

Please, do NOT use them.

SATA controllers and SATA Port Multipliers are some of the cheapest hardware, designed to make a number of hard drives accessible to Windows. A port multiplier takes a single port of a SATA controller and multiplexes it between several drives.

Windows typically only accesses one or two drives at a time, which means that the needs of Windows...

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[Ericloewe]

Golf clap for the title.

One important detail: at least at one point, Intel's chipset docs explicitly disavowed any compatibility with SATA port multipliers. The most reliable controllers don't even pretend to support them...

Another data point: When either Seagate or WD were developing a host-managed hybrid HDD with a few GB of NAND flash, they had the option of implementing a port multiplier to present two separate disks to the host. They found it too unreliable and ended up developing a custom controller that depended on a special driver to work properly.

 

[jgreco]

Golf clap for the title.

Well, you should know by now I try to create searchable titles that I can remember. I actually tend to find the URL's for links by banging in keywords from the title into the forum search (or Googe if forum search isn't working). Old habits die hard.

I am not certain what to do with your data points. While relevant, it seems like the whole topic consists of fragile components and magic driver hacks and minimal likelihood of success...

 

[Ericloewe]

Yeah, I wouldn't want to use either as the foundational argument for anything. Intel's docs change more often than one would expect and HDD design decisions are sort of weird on a good day. I think they work best as examples that the technology is not taken seriously.

 

[Arwen]

One other variation of the problem, is external SATA enclosures. Most multi-disk ones tend to use crummy RAID chipsets, some of which do include JBOD mode. That all most certainly translates to a variation of a SATA port multiplier protocol. (In order to allow the >=2 disks in JBOD mode to "share" a single eSATA port.)

 

[MutoSan]

And I can talk out of expirience. Just had a major failure because I used an onboard raid controller on a supermicro mainboard and a cheap pci-e Sata controller. Now I replaced both with a professional sas controller and so far all works again and I am replacing degraded disks.

 

[Trevor68]

typing freenas into ebay reveals things like this, does it look like the right thing to add some more sata ports to an old board?

LSI 6Gbps SAS HBA LSI 9240-8i = (9211-8I) IT Mode ZFS FreeNAS unRAID + 2* Cable | eBay

LSI 9240-8i IT Mode Raid + 2 SAS SFF-8087 to 4x SATA Cable. ETA 3 to 8 busines.

www.ebay.com.au

 

[MutoSan]

Yes but I would go the way I did. I bought a 16Port SAS controller and therefor I have no need anymore of the onboard controller. Also do not mix onboard and other controllers. Thats what I learned. LSI controller are on of the best. Mine is from Supermicro but the controller itself is from LSI.

 

[Trevor68]

Yes, but ashamedly my system is just an old HTPC repurposed, so consumer (read gamer) based gear.

 

[MutoSan]

thats not to bad. First FreeNas server was the same in my case. Just try not to use onboard controller and pci-e or pci controller at the same time. if you buy a SAS controller try to move all disk to it.

 

[Yorick]

Yes but I would go the way I did. I bought a 16Port SAS controller and therefor I have no need anymore of the onboard controller. Also do not mix onboard and other controllers. Thats what I learned. LSI controller are on of the best. Mine is from Supermicro but the controller itself is from LSI.

I have no qualm w/ mixing onboard SATA and LSI. The SuperMicro SATA on-board are fine, been running on an X11-SSH-F for going on 3 years now without issue; and added an LSI for more ports.

 

[jgreco]

Intel SATA is fine, as is PCH SATA/SAS. Both are known to be able to do hotplug properly. Some of the off-brand SATA/AHCI chipsets don't seem to do stuff like hotplug correctly, but are fine for attaching disks if you don't need hotplug. There are some SATA chipsets that just don't work well though, especially if you find them for $4.99 in a bin at Dick's Computer Emporium.

Older HBA's such as the 2008-based ones are actually a fair bit slower under load than a native 6Gbps AHCI controller. This won't make a significant impact on HDD's, but for SATA SSD, which can push the limits of even the best SATA controller, you are best off using mainboard SATA ports for your SSD's. Otherwise you may be losing some significant SSD speed to HBA overhead.

 

[MutoSan]

I have no qualm w/ mixing onboard SATA and LSI. The SuperMicro SATA on-board are fine, been running on an X11-SSH-F for going on 3 years now without issue; and added an LSI for more ports.

Yes I have been running it for over 5 years and then it happend. Lost almost all my data. Additionally YOUR setup is not equal to mine. I was talking about the onboard ports and a cheap no name Sata port controller. Never the less it is not a good way to go rather invest a few bugs more and have an LSI SAS controller with enough ports and all is good.

 

[BR14]

jgreco submitted a new resource:

Multiply your problems with SATA Port Multipliers and cheap SATA controllers - Bad technology, multiplied by more evil



Read more about this resource...

While totally agreeing, I would mention that LSI cards are known to have problems with non-server boards ( I remember having to tape over pins on IBM 1015 just to get an ASRock board to boot.)

 

[Ericloewe]

I'd be more inclined to put it the other way around. Some motherboards have a dubious SMBus layout. I seem to recall one board putting the DRAM SPD on the same SMBus as the PCIe slots.

 

[BR14]

I'd be more inclined to put it the other way around. Some motherboards have a dubious SMBus layout. I seem to recall one board putting the DRAM SPD on the same SMBus as the PCIe slots.

You are correct of course. I was not implying that LSI cards are substandard. I just think that people should be aware of possible problems when they plug a used LSI card into a PingPong Z370 board as it might not even boot.

 

[jgreco]

possible problems when they plug a used LSI card into a PingPong Z370 board as it might not even boot.

Well, that's certainly true, and is probably the reason behind why I lit off on a crusade to push people towards server-grade mainboards a decade ago... of course, you can then point out that the non-serverboard people are going to be the same ones thinking that going the SATA route is cheaper because servers are mystical $10-million dollar beasts.

 

[JmarcSyd]

I've posted my (positive) experience about the PH58 card running the JMB582 chipset there. In summary I think it's a good solution for booting from an M.2 SATA SSD drive in older PCs that have a limited number of SATA ports. I haven't tested the card as solution for main pool.