Need help Picking a HBA and Cables...

[Litlgi74]

Hello Folks...

I am currently using a SC846TQ Chassis with a Asus DSBV-D server Mobo. I am maxed out on drives and have decided to expand my server using SC847E16-R1K28JBOD

The expander has a BPN-SAS2-847EL1 and BPN-SAS2-847EL2 Backplane and a CSE-PTJBOD-CB2 control board.

I am currently using Flexraid and would like to keep the expander in JBOD mode... So I think this means I need an HBA instead of a RAID card?

I started a thread a while back on how to modify a SC846TQ for home use... but I have no experience with an expander.

Is there a "better" HBA to help me run all 45 bays in JBOD mode? Tamsolutions is sending some SAS cables with the expander, but I am not sure they will be useful to me... It looks like the are four ports for cables on the back of the expander, but do need to conned to all four? Four Cables?

Sorry for my ignorance... and thanks for your help.

 

[Rand__]

Have no seen this particular chassis before so no real experience, but the labels on the back seem to indicate that you only need to cables (HBA F/R). The expander F/R should be for cascading further JBODs using the appropriate backplane ports.

However, just keep in mind the bandwith point of view with 2 cables (=2x4 lanes SAS2 = 2x4x 750 MB/s max) so 24 discs will need to share 3GB/s (~125MB/disc), so not too much an impact even if you'd access all of them at the same time for full speed which is rather unlikely.

So SAS2 HBA is fine.

 

[brutalizer]

I have not connected my SC847 to my PC yet. I lack a 10m sff8088 cable. I dont know where to buy one.

 

[Rand__]

cant make do with 8m?
SAS Cables & Adapters - PC PitStop 8888-8M.asp

Link
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Dont look at the price

 

[brutalizer]

Thanks for the link to the cable.

I have a DELL external SAS HBA card, which works fine. I have connected it to a Omnistor 3016, which is a 16-disk chassis. SAS1, though. But it works fine.
https://www.servethehome.com/sgi-rackable-3u-16-bay-se3016-sas-expander-chassis-forum-deal/

The Dell 6Gbps SAS HBA has the advantage of being external SFF8088 only. If you have the IBM M1015 then you need to convert the internal sff8087 connections to external sff8088. This is not necessary with this DELL card, which is basically an IBM M1015, but external version.
A Cheaper M1015 - the Dell H200 and a HOWTO Flash

I am not really sure on this, but as I have understood it: The Supermicro case is cascaded. You need either:
1) Two sff8088 cables from your HBA to the case, which gives full speed.
2) One sff8088 cable from your hba to the case. This gives half the speed.
Inside the case, you can rewire the disks so all 45disks share one sff8088 cable, or use two different sff8088 cables. There are two SAS expanders in the case. either they are independent, so one expander drives 24 disks, and the other expander drives 21 disks = 45 disks. Here you need two sff8088 cables, one to each expander. Or, you can cascade the expanders, so they are connected. This means two expanders drive 24+21 disks which means you only need one sff8088 cable in this scenario. You can rewire the expanders behaviour at will, either cascade them or run the independently.