Bypassing a Dell Server Backplane

[EricTrujillo]

Team,

 

I have a acquired a Dell Poweredge 2900 while my RAID controller and drives were in shipping.

 

So I had an idea, can I use my new LSI card in this server while still running my new drives? My concern is that I bought 4TB drives and idk if the backplane will support it.

[Windows7ge]

Based on a .PDF file from Dell about the Poweredge 2900 it quoted the following:

Quote

Standard internal hard drive bays support up to eight 3.5” SAS or SATA hot plug hard drives;

There was no mention that the backplane for the drives is a SAS expander which means it should just be a direct pass-though for whatever RAID/HBA card you want to connect so yes you can use the RAID card you picked.

[EricTrujillo]

23 hours ago, Windows7ge said:

Based on a .PDF file from Dell about the Poweredge 2900 it quoted the following:

There was no mention that the backplane for the drives is a SAS expander which means it should just be a direct pass-though for whatever RAID/HBA card you want to connect so yes you can use the RAID card you picked.

Ok sweet, so that's hurdle number 1. Now I took the server apart today for fun/planning, in anticipation of my drives arriving tomorrow.

 

Now the thing that I think is gonna be a problem is this. The backplane has 2 SAS connectors, one for each row of drives. They're standard SFF-8482 connectors.

 

Now the cables I ordered are gonna be SFF-8087 to SFF-8482 and they're going to go to the LSI 9260-8i Card. However these cables have 4 SFF-8482 connectors a piece. Is it gonna matter at all what connector I use from the backplane to the card? How is the card gonna read the drives?

[Windows7ge]

16 minutes ago, EricTrujillo said:

Ok sweet, so that's hurdle number 1. Now I took the server apart today for fun/planning, in anticipation of my drives arriving tomorrow.

 

Now the thing that I think is gonna be a problem is this. The backplane has 2 SAS connectors, one for each row of drives. They're standard SFF-8482 connectors.

 

Now the cables I ordered are gonna be SFF-8087 to SFF-8482 and they're going to go to the LSI 9260-8i Card. However these cables have 4 SFF-8482 connectors a piece. Is it gonna matter at all what connector I use from the backplane to the card? How is the card gonna read the drives?

All that would be affected here is the order in which the RAID card would initialize the drives. You can connect them in any order but usually those breakout cables are numbered 1 2 3 4. So with 2 of them if the order bothers you you can connect them 1 2 3 4 1 2 3 4 or 1 1 2 2 3 3 4 4 it really doesn't matter. Now if you ever yank the drives and have to plug them back in putting them in slots they weren't in to begin with may or may not be a problem. I don't have enough experience will Hardware RAID to say if that should be a concern.

[EricTrujillo]

15 minutes ago, Windows7ge said:

All that would be affected here is the order in which the RAID card would initialize the drives. You can connect them in any order but usually those breakout cables are numbered 1 2 3 4. So with 2 of them if the order bothers you you can connect them 1 2 3 4 1 2 3 4 or 1 1 2 2 3 3 4 4 it really doesn't matter. Now if you ever yank the drives and have to plug them back in putting them in slots they weren't in to begin with may or may not be a problem. I don't have enough experience will Hardware RAID to say if that should be a concern.

Well yeah I'm not worried about the labeling, that I can do easily. The thing is, theres only 2 connectors on the backplane and 8 breakout cables in total. So that's where I'm confused. I dont know which one of the breakout cables I need to use.

[Windows7ge]

2 minutes ago, EricTrujillo said:

Well yeah I'm not worried about the labeling, that I can do easily. The thing is, theres only 2 connectors on the backplane and 8 breakout cables in total. So that's where I'm confused. I dont know which one of the breakout cables I need to use.

I'm confused by your question.

RAID Card -> breakout cables -> backplane -> HDDs

 

The two cables should be identical so I don't know what you mean by which one should you use.

[EricTrujillo]

Post Edited.

[EricTrujillo]

14 hours ago, Windows7ge said:

I'm confused by your question.

RAID Card -> breakout cables -> backplane -> HDDs

 

The two cables should be identical so I don't know what you mean by which one should you use.

I think its better if I explain it on video.

 

https://youtu.be/TbLF1sJe720

[Windows7ge]

43 minutes ago, EricTrujillo said:

I think its better if I explain it on video.

 

https://youtu.be/TbLF1sJe720

It says the video is private.

[EricTrujillo]

17 minutes ago, Windows7ge said:

It says the video is private.

I changed it now, it was set to private, I meant to put it as unlisted. Sorry about that.

[Windows7ge]

Well this doesn't look good. Are you sure those cable ends are the connectors you think they are? You don't want breakout cables here. The documentation doesn't state there's a SAS expander but if there's only two connectors they may be proprietary or another standard.

[EricTrujillo]

17 minutes ago, Windows7ge said:

Well this doesn't look good. Are you sure those cable ends are the connectors you think they are? You don't want breakout cables here. The documentation doesn't state there's a SAS expander but if there's only two connectors they may be proprietary or another standard.

You know what? You're right. The connectors aren't the right standard, however, what I can do, is just run this thing without the backplane. I'll take it out of the server completely, and then just run the drives directly connected to the breakout cables to the new LSI card. The drive cages should hold them in there securely enough for them to run without me worrying about it. Its ghetto, but it will work.

[Windows7ge]

3 minutes ago, EricTrujillo said:

You know what? You're right. The connectors aren't the right standard, however, what I can do, is just run this thing without the backplane. I'll take it out of the server completely, and then just run the drives directly connected to the breakout cables to the new LSI card. The drive cages should hold them in there securely enough for them to run without me worrying about it. Its ghetto, but it will work.

What LSI card are you using? I'd imagine it uses SFF-8087? If you do enough researching you might find the name for those connectors and locate a SFF-8087 to that backplane adapter.

 

Do you have a picture of what the cable end looks like going into the backplane?

[AbsoluteFool]

Probably the same cables PDE 2950 uses. This will be SFF-8484 that goes to the backplane, there are cables available that goes from SFF-8087 that will fiT your HBA and SFF-8484 that you can put into the controller. 

[EricTrujillo]

15 hours ago, AbsoluteFool said:

Probably the same cables PDE 2950 uses. This will be SFF-8484 that goes to the backplane, there are cables available that goes from SFF-8087 that will fiT your HBA and SFF-8484 that you can put into the controller. 

Yeah that's what it is. What I really need on this setup is an SFF-8484 to SFF-8087 cable, I found them on Monoprice for about 11 dollars. I went with a different solution, but if it doesn't work, then I'll order these and return the rest of the stuff I ordered.

 

Thanks for all the help guys!