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Stonelesscutter

SAS/SATA controller questions

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Hi. I'm looking for advice as I've never built an unraid server before.

 

I got myself 4 SilverStone FS304 cages with room for 16 3.5 inch drives altogether. I understand I will need a SATA/SAS controller to connect it all up to the motherboard. I would prefer to use just a single PCIe slot, so I'll be looking for a 16 port card. There will be a fair distance between the motherboard and the drive cages, perhaps about 1.20 - 1.30 meters.

 

  • Could anyone recommend me one or more types of 16 port card that are good but still fairly affordable?
  • Is there anything in particular I need to look out for to ensure that it would work well with unraid?
  • Can you offer any advice in regard to what I would require to connect the drives over a distance, preferably with a minimal amount of cables to run?

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Posted (edited)

I'm was in a similar situation as you, I have 16 bays and wanted to use a single PCI-E slot. I was looking at the LSI 9211-16i which can expand out to 16 drives. I was actually going to get 2x LSI 9211-8i, but ended up going with 2x Dell H310 cards and flashed them to IT mode. The LSI 9211-16i was ~$200 CAD, LSI 9211-8i's were around ~$50 each, and the Dell H310's I got for $30 each locally. Figured the $140 I saved, I could just get another motherboard that supported 3 PCI-E slots in the future when/if I needed it.

 

Here's a nice video detailing the most common cards used.

Edited by nnhoang
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17 hours ago, Stonelesscutter said:

There will be a fair distance between the motherboard and the drive cages, perhaps about 1.20 - 1.30 meters.

Note that max cable length for SATA is 1 meter.

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9 hours ago, johnnie.black said:

Note that max cable length for SATA is 1 meter.

Thanks for reminding me. I should still be able to make that work, since the design isn't yet finalized. I do wonder though, I've heard of PCI extender cables, if I were to find such a thing, would the 1 meter max distance for SATA cables count from the motherboard, or would it count from the SATA controller card?

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20 hours ago, nnhoang said:

I'm was in a similar situation as you, I have 16 bays and wanted to use a single PCI-E slot. I was looking at the LSI 9211-16i which can expand out to 16 drives. I was actually going to get 2x LSI 9211-8i, but ended up going with 2x Dell H310 cards and flashed them to IT mode. The LSI 9211-16i was ~$200 CAD, LSI 9211-8i's were around ~$50 each, and the Dell H310's I got for $30 each locally. Figured the $140 I saved, I could just get another motherboard that supported 3 PCI-E slots in the future when/if I needed it.

 

Here's a nice video detailing the most common cards used.

Thanks! That was a good video to watch. And the guy made a follow-up video for 2020 which I'm currently still watching. Of course, as is usually the case, more information brings up more questions. :) 

 

So, now I've seen a lot of these cards, I'm noticing that a lot of them only have 2 connectors, which I think are the cards with the 8 SAS lanes. So between a card like this and the hard drives, it would appear that more is needed than simply a number of SATA cables. How do these two connectors get divided into 8 SATA ports? What is the missing part called?

 

What is IT mode? Which other varieties besides this IT mode exist? How do I know if I should have an IT mode card or not?

 

One of my initial questions also still stands, but let me rephrase it a little. Are there any things I should absolutely avoid (regarding these controllers) when I want to use unraid and are there any things which would be a plus when I want to use unraid?

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No expert but there are special cables that connect 1 SAS port to 4 SATA ports. I think there are several types, so ask before buying.

I think the guy from Art of Server has a video about it but I didn't watch it yet.

For the IT mode I think it just allows direct disk acces without the RAID layer on the board, that's what you want to do software Raid (FreeNAS) or similar (Unraid).

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21 minutes ago, ChatNoir said:

No expert but there are special cables that connect 1 SAS port to 4 SATA ports. I think there are several types, so ask before buying.

I think the guy from Art of Server has a video about it but I didn't watch it yet.

For the IT mode I think it just allows direct disk acces without the RAID layer on the board, that's what you want to do software Raid (FreeNAS) or similar (Unraid).

Hmm... so is this why the guy from Art of Server mentions flashing the cards perhaps? Maybe the cards are basically RAID cards but the same hardware can be used for direct access by flashing a new firmware onto them?

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Posted (edited)
1 hour ago, Stonelesscutter said:

What is the missing part called?

You need a forward breakout cable like this one (x2) I purchased on Amazon for my Dell H310 in IT mode.

 

It's a Mini-SAS SFF-8087 to 4 SATA connectors cable.  Be careful not to get a reverse breakout cable which looks exactly the same.

 

Sometimes they are not labelled forward or reverse breakout; however you need to make sure you get a forward breakout cable or the drives attached to the HBA will not be recognized.

 

UPDATE: the one I bought is out of stock but here is an in stock equivalent item.

Edited by Hoopster

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What is IT mode? Which other varieties besides this IT mode exist? How do I know if I should have an IT mode card or not?

IT stands for "initiator target". 

 

Basically it presents attached drives individually to the host and not as a RAID.  It basically makes the card a pass-through controller allowing unRAID to see the drives as if they were attached to individual non-RAID MB SATA ports.

 

The Dell H310, by default, is a RAID card with RAID firmware.  On some cards it is possible through the RAID firmware to present the drives as a JBOD or RAID0 so they appear as individual drives; however, it is much easier and more reliable to just replace the RAID firmware with IT firmware.

 

 

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I just found a cheap option for a 16 port internal controller, but it's an old model, using PCIe 1.0a. If I'm not mistaken, the 3 Gb/s rating per port works out at 96 MB/s per drive. Please correct me if I'm wrong on that. That doesn't even seem that low. Hard drives these days do like 150-250 MB/s, if I'm not mistaken. Of course, I would really prefer a card which utilizes a newer PCIe version. The motherboard I'll be going for should have PCIe 4.0. But for the controller card, maybe PCIe 2.0 would be enough? Anyway, at 18 pounds including VAT, this card seems like a bargain option. Specifications in attached PDF. Any thoughts?

LSI_SAS_84016E_ITM_528.pdf

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1 hour ago, Stonelesscutter said:

Any thoughts?

LSI SAS1 controllers are limited to 2.2TB max device size, look for a SAS2 or newer model.

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7 hours ago, johnnie.black said:

LSI SAS1 controllers are limited to 2.2TB max device size, look for a SAS2 or newer model.

Thanks! That's rather important to know.

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I'm not familiar with that controller, but it's a RAID controller, so likely not a good option, look for any LSI with a SAS2008/2308/3008/3408 chipset in IT mode, e.g., 9201-8i, 9211-8i, 9207-8i, 9300-8i, 9400-8i, etc and clones, like the Dell H200/H310 and IBM M1015, these latter ones need to be crossflashed.

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1 hour ago, johnnie.black said:

I'm not familiar with that controller, but it's a RAID controller, so likely not a good option, look for any LSI with a SAS2008/2308/3008/3408 chipset in IT mode, e.g., 9201-8i, 9211-8i, 9207-8i, 9300-8i, 9400-8i, etc and clones, like the Dell H200/H310 and IBM M1015, these latter ones need to be crossflashed.

Thanks. I see plenty of such cards around, but for the moment I'm really trying to find a card with 4 internal ports, or 16 ports depending on how you're counting. Apparently some cards say 4 port while it's only a single port or 8 ports when it's a duo port, for example. I keep running into cards with 4 external ports, but the ones with internal ones appear to be somewhat rare.

 

I know I could go for a duo-port card and add an extender, but that would often mean taking up two PCIe slots on the motherboard again. There are options apparently for extenders which don't need to be slotted into a PCIe slot and could just receive power from the PSU. That might be an option I would have to look at later. Right now I've just started orienting myself on these controllers, so I'm not yet ready to give up on my ideal solution of a card with 4 internal ports. There is also the option of using a card with external ports and rerouting the cables back into the case, but again this would not be the neatest solution.

 

From what I've seen so far, the cards with 4 internal ports seem to be multiple times as costly as the ones with external ports. This makes no sense to me. Also the ones with 4 ports are much more expensive than the ones with 2 ports, which also seems quite disproportionate.

Edited by Stonelesscutter

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4 minutes ago, Stonelesscutter said:

or 16 ports depending on how you're counting

There are 16 port versions of some of the models posted, I only list the 8 ports models since they are the most wanted, but look for LSI models ending in -16i

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22 minutes ago, johnnie.black said:

There are 16 port versions of some of the models posted, I only list the 8 ports models since they are the most wanted, but look for LSI models ending in -16i

Thanks, I will have a look at that.

 

Ran across another Adaptec 16 port card in the meantime. Adaptec 71605. Seems to be PCIe 3 version.

https://www.adaptec.com/nr/pdfs/integration_guide_71605-71605E.pdf

 

I suppose it's a RAID card again. But wouldn't it be possible to "flash" these cards to work in IT mode as well?

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Sorry, no idea, never had Adaptec HBAs, though I know some users are using them with Unraid, but don't remember the specif models, you can try searching the forum.

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@johnnie.black

I just placed a bid on eBay on a card called LSI MEGARAID SAS 9260-16I 16-PORT (4X SFF-8087) 6GB/S SATA+SAS RAID CONTROLLER. Maybe I acted a bit hastily there. That model is not among the ones you mentioned in your post above. Would this one work for my unraid server, or should I retract my offer as soon as I can?

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1 hour ago, Stonelesscutter said:

I just placed a bid on eBay on a card called LSI MEGARAID SAS 9260-16I

I think that card supports RAID firmware only.  If so, the chipset it uses offers no possibility of cross flashing to IT firmware.  Unless you want to configure all attached drives as RAID 0, unRAID will likely not see any drives attached to this card.

 

It is SATA II only but that is no issue if you are just attaching HDDs to it and not SSDs (not recommended anyway unless it is a modern chipset that supports deterministic TRIM on SSDs).

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25 minutes ago, Hoopster said:

I think that card supports RAID firmware only.  If so, the chipset it uses offers no possibility of cross flashing to IT firmware.  Unless you want to configure all attached drives as RAID 0, unRAID will likely not see any drives attached to this card.

 

It is SATA II only but that is no issue if you are just attaching HDDs to it and not SSDs (not recommended anyway unless it is a modern chipset that supports deterministic TRIM on SSDs).

Thanks Hoopster. I believe I managed to retract the offer. Man, this stuff is tricky. Next time I'll ask for advice first and then decide if I want to buy. :) 

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18 minutes ago, Stonelesscutter said:

this stuff is tricky

It can be confusing, but any LSI that has MegaRAID in the model name can be left off the buy list.

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4 minutes ago, Stonelesscutter said:

this stuff is tricky

Since you want a card that supports 16 drives, perhaps you can find a good used LSI 9201-16i.  It is an HBA card so no RAID and no flashing to IT firmware.  It will work as-is with unRAID.  It is only PCIe 2.0, but, with spinners it should not be too much of a concern.

 

The 9400-16i is a PCIe 3.0/3.1 card or you could also go up to the LSI 9305-24i  (also PCIe 3.0) for support of 24 attached drives.  Both have been reported to work with unRAID.

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