Greetings, 

 

This is my first Unraid build and I'm looking for some advice on a HBA/SAS card that will connect the two enclosures below.

I don't have a lot of experience with enterprise hardware so it has been a little bit of a learning curve. There is some great information in these forms if you know what to look for, though i'm still not sure i understand it fully.  

 

I have the following hardware; 

 

IBM x3650 m2 7947 - 12 x 2.5" bays (currently using

Expansions Slots

• Two PCI Express riser cards with two PCI Express x8 slots (x8 lanes) each

2 x IBM EXP3000 - 12 x 3.5" bays each  

 

I have already flashed a M1115 for the internal drives and installed Unraid and all seems to be working well. I'm unsure as to what would be best for connecting the two enclosures with the existing riser cards. 

 

Would a single LSI9208e suffice or is there something else i should consider? 

 

I've attached a internal shot of the x3650 

 

Any advice would be great!

 

Thank you.

 

Hmm. It seems the EXP3000 has built-in expanders and only needs a minimum one a single link to each EXP3000.

so a single LSI9208e should be enough... unless EXP3000 has dual ESMs... in which case another LSI9208e may be necessary.

Thanks ken-ji. 

 

Both EXP3000 only have one ESM at the moment. From what i could deduce from page 12 of the manual is that dual ESMs are used for redundancy only... ?

 

I've been looking over at

thread again and wondering if i could be better off with 2 x 6Gb/s cards as there seems to be a significant performance hit with using a single card with a single link and 24 disks.

 

Are there any other cards i could consider besides the LSI9208e if my intension was the purchase two? The majority of the 8e cards seem to the two port of 4 x 4, except for this 9300 12Gbs card which is described as a 8e, but only has a single port... 

Edited July 21, 20178 yr by i742877
clarity

Sorry, just realized I wasn't clear.

A single 9208e card your getting has 2x 4x ports. Each EXP3000 ESM only requiring a single 4x port to work with. Thus a single 9208e card should be able to access each EXP3000 at 4.8Gb/s - of course 12 drives in a EXP3000 would mean a theoretical max speed of 40MB/s. @johnnie.black would have better numbers for the actual real world performance.

 

Thanks for sticking with me  

 

I thought the speed would be more like 95MB/s as per the diagram at ?

I take it there is no speed disadvantage in this situation to getting a 16e card ? There is a SAS9201-16e available locally. 

my bad.

 

I've forgotten how to do the computations...

the diagram you've quoted above is exactly the case for a single 9200-8e card.

 

There will be no speed disadvantage with a 16e (however, the 16e might be a PCIe 3.0 card - thus possibly giving you better bandwidth)

 

So you need to take this into account: Is your server populated with PCIe3.0 capable Xeon(s)?

Eeep! 

 

I'm not sure if it is a PCIe3.0 Xeon, 

 

I believe it is this 

 

http://ark.intel.com/products/40200/Intel-Xeon-Processor-E5520-8M-Cache-2_26-GHz-5_86-GTs-Intel-QPI

 

 

That server uses PCIe 2.0, I assume you'll be using SATA3 disks?

At the moment there are just the existing SATA2 disks in there, but yes, i was intending on using SATA3 in the enclosures and SSDs in the x3650 itself 

OK, if you're not using SAS3 disks and since the server is PCIe 2.0 no point in buying a more expensive PCIe 3.0 and/or SAS3 HBA, of course you can for future proofing.

 

Each x4 mini SAS link will have 2400MB/s bandwidth, of those 2200MB/s are usable, so if you use 2 HBAs, one for each EXP3000 you'll have around 180MB/s for each disk during parity checks/rebuilds (note: this with all SATA3 disks, using some SATA2 disks will bring the whole speed down), if you use a single HBA for both EXP3000 the bottleneck will be the x8 PCIe 2.0 slot, this can vary a little from board to board but in my experience ii's between 2500 and 3000MB/s, so you'd get around 100/125MB/s per disk during parity check/rebuilds.

 

Excellent! That is just as i expected. Thank you for the clarification!

 

Since i'll now be looking at two cards, is there something else besides the LSI9208e to consider?

46 minutes ago, i742877 said:

Since i'll now be looking at two cards, is there something else besides the LSI9208e to consider?

 

I have one of those and it's the one I would recommend, correct model is 9200-8e.