SAS Noob needing clarification

[Binary Buddha]

So I'm trying to figure out what I need to add more drives. My motherboard has SAS ports. I'm assuming what I'm looking for is a SAS expander card? The PCI-e looking thing just just uses the PCI bus for power and connects to the MB SAS port.

What's the difference between a SAS expander and an SAS Controller?

I'm eyeballing getting a IBM ServeRAID M1015. That's a SAS Expander right? Do I need the Mini-SAS to Mini-SAS cable and the Mini-SAS to SATA fan out cable to add SATA drives?

Since I have SAS ports on the motherboard, can I just side the Expander/Controller card thing and get away with using one of the Mini-SAS to SATA fan out cables?

The documented map of the MB SAS ports look like SATA ports. Do the Mini-SAS cables connect to those ports?

 

[Johnnie Black]

If your sig is correct the board already has an LSI SAS controller onboard, for the first 8 devices you only need the cables, if you want to use more than 8 devices you need a SAS expander, just make sure the controller is set to IT mode.

 

[Binary Buddha]

If your sig is correct the board already has an LSI SAS controller onboard

Um... What part of my Sig are you referring to?



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[Johnnie Black]

Um... What part of my Sig are you referring to?

SPECS:[Supermicro MBD-X9SRH-7F-O]

 

[danb35]

I'm eyeballing getting a IBM ServeRAID M1015. That's a SAS Expander right?

No, it's a SAS HBA (controller).

 

[Binary Buddha]

SPECS:[Supermicro MBD-X9SRH-7F-O]

so I don't need one of the cards? I can just use one of the fan out cables?


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[Binary Buddha]

No, it's a SAS HBA (controller).

Other than the obvious that the titles imply, what's the difference between an expander and controller? I'm just wondering why the recommended hardware states I should use that controller with my MB when it apparently already has a controller.


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[Johnnie Black]

I can just use one of the fan out cables?

Yes.

 

[danb35]

what's the difference between an expander and controller?

You've read @jgreco's SAS primer? Because I'm pretty sure this would be answered there.

recommended hardware states I should use that controller with my MB

Which "recommended hardware" makes that recommendation?

 

[Binary Buddha]

You've read @jgreco's SAS primer? Because I'm pretty sure this would be answered there.

Which "recommended hardware" makes that recommendation?

Just read over the Primer... Very useful... But, still omits a statement about a controller vs an expander.

https://forums.freenas.org/index.php?threads/hardware-recommendations-read-this-first.23069/

 

[danb35]

still omits a statement about a controller vs an expander.

It appears to explain quite clearly what an expander is. You know what a controller is, right?

https://forums.freenas.org/index.php?threads/hardware-recommendations-read-this-first.23069/

What part of this (noted at the top to be outdated) guide says "you should use a M1015 with a Supermicro MBD-X9SRH-7F-O" with no other qualifiers? Because I see:

• A recommendation for the X9SRH as a top-end board, and
• "The IBM ServeRAID M1015, crossflashed to IT mode, is probably one of the best choices available if you need a bunch of extra SATA/SAS ports." (emphasis added)

I don't see anything making a universal recommendation of the M1015, nor anything recommending the M1015 if you're using the X9SRH. I wouldn't see any need for a M1015 unless (1) you needed more ports than were onboard, and (2) you didn't have an expander backplane or otherwise want to mess with an expander.

 

[Binary Buddha]

It appears to explain quite clearly what an expander is. You know what a controller is, right?

What part of this (noted at the top to be outdated) guide says "you should use a M1015 with a Supermicro MBD-X9SRH-7F-O" with no other qualifiers? Because I see:

• A recommendation for the X9SRH as a top-end board, and
• "The IBM ServeRAID M1015, crossflashed to IT mode, is probably one of the best choices available if you need a bunch of extra SATA/SAS ports." (emphasis added)

I don't see anything making a universal recommendation of the M1015, nor anything recommending the M1015 if you're using the X9SRH. I wouldn't see any need for a M1015 unless (1) you needed more ports than were onboard, and (2) you didn't have an expander backplane or otherwise want to mess with an expander.

Sorry. Like I said.... I is noob. I assumed an expander was like a controller. But, you use an expander to get more SAS ports. It doesn't convert SAS into SATA ports.

Yeah... I need more SATA ports.

 

[Johnnie Black]

Just in case you don't know, you can use SATA disks with a SAS HBA with or without an expander.

 

[Binary Buddha]

Just in case you don't know, you can use SATA disks with a SAS HBA and/or expander.

Lol... thanks... So now the question is if I need to do some sort of special config when I use the SAS to SATA fan out cables on a controller. I'm assuming no...

 

[Johnnie Black]

No, you just need the correct cables.

 

[CraigD]

SAS Expander vs Controller - think of it this way, every 4 lanes on a SAS controller (8087 / 8088 / 4x SATA ports) = a wall power-socket. A SAS expander acts as a multi box / power-strip. So you are able to daisy chain expanders together to support as many drives as you want.

In your case (from the hardware listed in you signature);
You have 6 SATA (White and black) and 8 SAS ports (blue SATA connectors) on your motherboard, so you can run 14 drives natively with normal SATA cables.
Running FreeNAS make sure your motherboard SAS controller has been flashed to IT mode

If you need more than the 14 drives, you can add;
1) use 1 or 2 8087 to 4xSATA reverse breakout cables from the blue SAS ports into a SAS expander and then run up to 6 8087 to 4xSATA forward breakout cables to the SATA drives (30 drives)

2) Add a M1015 or similar (IT mode) and 2 8087 to 4xSATA forward breakout cables to the SATA drives (till using the motherboard connectors) (22 drives)

Have Fun
PS re-purpose the 8-port SATA controller as it is not FreeNAS recommended.

 

[Binary Buddha]

If you need more than the 14 drives, you can add;
1) use 1 or 2 8087 to 4xSATA reverse breakout cables from the blue SAS ports into a SAS expander and then run up to 6 8087 to 4xSATA forward breakout cables to the SATA drives (30 drives)

So, I do a fanout cable from the motherboard to the expander? I thought I just needed SAS to SAS cable from blue motherboard port to SAS expander. Then I can use the SAS to SATA breakout cables from the expander to the drives.

 

[CraigD]

So, I do a fanout cable from the motherboard to the expander? I thought I just needed SAS to SAS cable from blue motherboard port to SAS expander. Then I can use the SAS to SATA breakout cables from the expander to the drives.

I wrote instructions for this board with links: reverse breakout from the motherboard to expander, then forward breakout from expander to drives (the cables look exactly the same but they are not bidirectional)

Have Fun

 

[Binary Buddha]

(the cables look exactly the same but they are not bidirectional)

** Slams head on keyboard**

Sorry... More noobing... How am I supposed to know the difference? Accounting for some seller accidentally miss labeling the cables.



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