Hi
Got a question about the backplane model SAS2-846EL1 found on the SC846 series chassis.
The SC846BE16-R920B chassis is the one I'm looking at.
See the pdf documentation here, Appendix E, page E-3.
http://www.supermicro.nl/manuals/chassis/tower/SC846.pdf
It's a 24 bay chassis, but the backplane only got 3 SFF-8087 connectors.
Number 7 to 9 on the illustration, marked as Primary SAS connector: PRI_J0 (and J1 and J2).
The three other SFF-8087 are for the EL2 variant of the backplane so please ignore them.
On page E-5 we can read that: (loosely quoted to reflect only this backplane model)
"The primary SAS connectors provide expander features including cascading and failover.
From right to left the ports are Primary 0, Primary 1"
Not sure what they mean by that, is the Primary 0 for cascading and Primary 1 for failover?
And shouldn't that be Primary1 and Primary2 instead?
(Or, I can see that in a multiple cascading system you can use Primary 0 as a cascading port as well)
And as we can see on page E-13, a common way to connect a HBA to the backplane is at Primary 0.
With a SFF-8087 cable.
The rest of the examples illustrates the usage of Primary 1 as a cascading port only.
Primary 2 connector is never used in the illustrations. I guess failover only.
Another point is that on the chassis webpage it states:
"Single input/output SFF 8087 connectors".
My understanding is that a SFF-8087 connector/cable can handle 4 SAS/SATA 6Gb/s channels, providing for 4 HDD's.
So how can that backplane, using only 1 SFF-8087 connector, provide for the maximum of 24 HDD's at 6Gb/s?
Even if all three SFF-8087 connectors can be used as input, it'll cover only 12 of the HDD's, as far as know. (Or each needs to handle 8 HDD's).
I guess my knowledge is messed up, so please educate me on this topic.
The reason I'm asking is that I need to figure out if this chassis with that backplane can work with my LSI SAS9211-8i 6Gb/s HBA.
The card got 2 SFF-8087 ports, each can provide 4 SAS/SATA 6Gb/s HDD's.
So the question is, since the LSI HBA card has 2 SFF-8087 to provide for 8 drives, and the backplane only got 1 input SFF-8087 connector,
I would only be able to use 4 of the 24 drivebays in the chassis?
(Or is there a dual SFF-8087 to singel SFF-8087 cable that can give me all 8 drives, or what's the solution here?)
Basically, I'm not going to be happy using my HBA card with this backplane I guess?
My primary need is to be able to use the HBA that I've got, no need for more then 8 drives in a while.
Also, the HBA needs to be compatible with ESXi 5.1 so that I can use passthrough (the whole HBA to a virtualmachine running my ZFS based NAS and with IT firmware)
But if that's not possible, what's the solution to get all 24 drivebays operational? (or anything from 8 and upwards)
Got a question about the backplane model SAS2-846EL1 found on the SC846 series chassis.
The SC846BE16-R920B chassis is the one I'm looking at.
See the pdf documentation here, Appendix E, page E-3.
http://www.supermicro.nl/manuals/chassis/tower/SC846.pdf
It's a 24 bay chassis, but the backplane only got 3 SFF-8087 connectors.
Number 7 to 9 on the illustration, marked as Primary SAS connector: PRI_J0 (and J1 and J2).
The three other SFF-8087 are for the EL2 variant of the backplane so please ignore them.
On page E-5 we can read that: (loosely quoted to reflect only this backplane model)
"The primary SAS connectors provide expander features including cascading and failover.
From right to left the ports are Primary 0, Primary 1"
Not sure what they mean by that, is the Primary 0 for cascading and Primary 1 for failover?
And shouldn't that be Primary1 and Primary2 instead?
(Or, I can see that in a multiple cascading system you can use Primary 0 as a cascading port as well)
And as we can see on page E-13, a common way to connect a HBA to the backplane is at Primary 0.
With a SFF-8087 cable.
The rest of the examples illustrates the usage of Primary 1 as a cascading port only.
Primary 2 connector is never used in the illustrations. I guess failover only.
Another point is that on the chassis webpage it states:
"Single input/output SFF 8087 connectors".
My understanding is that a SFF-8087 connector/cable can handle 4 SAS/SATA 6Gb/s channels, providing for 4 HDD's.
So how can that backplane, using only 1 SFF-8087 connector, provide for the maximum of 24 HDD's at 6Gb/s?
Even if all three SFF-8087 connectors can be used as input, it'll cover only 12 of the HDD's, as far as know. (Or each needs to handle 8 HDD's).
I guess my knowledge is messed up, so please educate me on this topic.
The reason I'm asking is that I need to figure out if this chassis with that backplane can work with my LSI SAS9211-8i 6Gb/s HBA.
The card got 2 SFF-8087 ports, each can provide 4 SAS/SATA 6Gb/s HDD's.
So the question is, since the LSI HBA card has 2 SFF-8087 to provide for 8 drives, and the backplane only got 1 input SFF-8087 connector,
I would only be able to use 4 of the 24 drivebays in the chassis?
(Or is there a dual SFF-8087 to singel SFF-8087 cable that can give me all 8 drives, or what's the solution here?)
Basically, I'm not going to be happy using my HBA card with this backplane I guess?
My primary need is to be able to use the HBA that I've got, no need for more then 8 drives in a while.
Also, the HBA needs to be compatible with ESXi 5.1 so that I can use passthrough (the whole HBA to a virtualmachine running my ZFS based NAS and with IT firmware)
But if that's not possible, what's the solution to get all 24 drivebays operational? (or anything from 8 and upwards)