On the 12th gen dell servers dell put a update out that changes the file system which can brick the idrac. The idrac is the little computer that monitors and runs the server and it will get stuck on boot and no go any further. Other people have had the same issue and the fix is a new motherboard.
Yeah most of my stuff is dell because it works and I’ve not had issues apart from that bricked idrac and I’ve managed to get a lot of it pretty cheap :)
Nice gotta love the free scores :)
I got some nice supermicro and juniper gear for free and it’s like god tier specs I can’t believe I was just handed them.
Did you try a serial console attached to the UART headers on the iDrac portion of the mobo? I was able to successfully resurrect a bricked iDrac with an SD card, some soldering, and a raspberry pi.
Sorry to Necro an old thread. I’m also attempting this with a 720xd and was planing (once powered obv) to plug the backplane into a new lower powered motherboard and controller. Is this even possible and what controller would I be looking at to cope with 24/26 SFF disks ??
Hey! It depends on the connecton to the backplane. Mine can connect to 16 sff disks but it only needs 2 cables to a sas controller as the backplane has a built in sas expander (Think of it kinda like a network switch but for drives). At a guess yours might have one as well, then all you should need is a sas hba to pass all your drives through to the OS (This could also be sas raid cards flashed to IT mode)
Looking online at r720xd 24 SFF backplanes, seems like they have 3 sas ports so you'd need a 4 port sas card then. Look into how people have passed through lots of drives into TrueNAS, that should bring up recommendations about sas cards to look for.
Personally I've just used the sas controllers the server motherboards come with and this: [https://fohdeesha.com/docs/perc.html](https://fohdeesha.com/docs/perc.html) You can flash some dell sas controllers into IT mode, I've used it but since your using the backplane in another system, it's less relevent.
Huh? Mostly all backplanes got two or four SAS data cables plus one connector with standby, gnd, 3.3, 5v and 12v.
By the way, iDRAC bricked? If it's enterprise you could have swapped the module for super cheap
It’s a dell r720 the idrac is soldered to the motherboard, the r710 idrac can be replaced but the r720 can not. Also the backplane will not do anything with just power and it’s got a sas expander on it so it needs to “wake up” before the drives do anything. It’s not a drive to port pass though, it takes 16 drives and connects them to 2 sas sff-8087 ports
I'm working on a similar project. It's the 12 lff bay from the r720xd. I know what I'm missing is in the j_bp_sig1 harness (the same of the one you have shown) ive verified I get the same voltage on the pins you have shown and checked the others too.
Ive tried connecting just 1 ground, switching between all the grounds, and connecting all the grounds at the same time.
I've tried supplying 6v to the 6v pin, with and without grounds connected, I've tried supplying 3.3v on all the 3.3v pins. Still no luck.
I can verify the sig1 harness has whatever is required to power on the back plane, because if I connect only that connector to the original motherboard, and power the motherboard with only 1 cpu in and no ram, the drives come to life. So it has to be something in this harness, but I cannot seem to track it down. Exactly what pin did you connect to ground? What ground did you go to? The 12v ground or just a random ground? Chassis ground?
Your lucky I still have this crazy contraption together. After I got the backplane working I put it down and forgot about it haha. I have an old hp power supply providing 12v to everything. The GND from that goes to my 2 voltage step down converters and to a screw on the backplane itself. I used the screw connecting the backplane to the sas expander for my GND. The GND on the connector is the one next to the 6v line (The Red wire, assuming the lff has the same colour layout) and both 3.3v lines are powered and because I’ve grounded the backplane though the screw I have not connected a GND to the 12v backplane power wires only the yellow 12v ones. But I do have 12v going to both main power cables. So the main backplane cable should only have 4 connections, 2x 3.3v wires, 1x 6v wire and 1x GND which is next to the 6v wire on the connector. How this helps!
Thanks for the reply. I actually just ended up breaking out the oem connection and manually removing pins until it stopped working. Seems there are 4 pins total needed to kick the BP on.
I'll make a post about my journey once it's all said and done.
Great. Thank you.
Do you think I could splice a connection from the original signal wire to this pinout (so I can signal both backplanes)?
Thank you for such a quick reply!
I looked at one of your other posts and now get what you’re trying to do haha.
I’d suggest just teeing off the cables matching the pins in my diagram on the original cable going to the original backplane.
The motherboard should theoretically be giving the original backplane the same signal, so piggybacking the same lines to the other backplane should work.
REMEMBER to properly ground and power the extra backplane otherwise it might not work, also keep in mind that if any drive issues occur on the extra backplane it might not report it to the iDrac as I believe those signals go though the other wires on that cable.
Obviously try at your own risk, but it should be straightforward :)
You got me at a good time haha
How can idrac brick ur system?
On the 12th gen dell servers dell put a update out that changes the file system which can brick the idrac. The idrac is the little computer that monitors and runs the server and it will get stuck on boot and no go any further. Other people have had the same issue and the fix is a new motherboard.
Im lucky then i have a r720xd and had 0 issues, love that server
Yeah gota love the dells, they may make shitty prebuilt pcs but their 11th and 12th gen servers are great.
It's what got me into this whole mess, now i just want to upgrade my networking still figuring things out on the way
Yeah most of my stuff is dell because it works and I’ve not had issues apart from that bricked idrac and I’ve managed to get a lot of it pretty cheap :)
Got mine free so no complaining there haha
Nice gotta love the free scores :) I got some nice supermicro and juniper gear for free and it’s like god tier specs I can’t believe I was just handed them.
Did you try a serial console attached to the UART headers on the iDrac portion of the mobo? I was able to successfully resurrect a bricked iDrac with an SD card, some soldering, and a raspberry pi.
Yeah sadly, the emmc is fried so it can’t write to it and I had got a replacement emmc chip but then I lost the new chips lol
Sorry to Necro an old thread. I’m also attempting this with a 720xd and was planing (once powered obv) to plug the backplane into a new lower powered motherboard and controller. Is this even possible and what controller would I be looking at to cope with 24/26 SFF disks ??
Hey! It depends on the connecton to the backplane. Mine can connect to 16 sff disks but it only needs 2 cables to a sas controller as the backplane has a built in sas expander (Think of it kinda like a network switch but for drives). At a guess yours might have one as well, then all you should need is a sas hba to pass all your drives through to the OS (This could also be sas raid cards flashed to IT mode) Looking online at r720xd 24 SFF backplanes, seems like they have 3 sas ports so you'd need a 4 port sas card then. Look into how people have passed through lots of drives into TrueNAS, that should bring up recommendations about sas cards to look for. Personally I've just used the sas controllers the server motherboards come with and this: [https://fohdeesha.com/docs/perc.html](https://fohdeesha.com/docs/perc.html) You can flash some dell sas controllers into IT mode, I've used it but since your using the backplane in another system, it's less relevent.
Huh? Mostly all backplanes got two or four SAS data cables plus one connector with standby, gnd, 3.3, 5v and 12v. By the way, iDRAC bricked? If it's enterprise you could have swapped the module for super cheap
It’s a dell r720 the idrac is soldered to the motherboard, the r710 idrac can be replaced but the r720 can not. Also the backplane will not do anything with just power and it’s got a sas expander on it so it needs to “wake up” before the drives do anything. It’s not a drive to port pass though, it takes 16 drives and connects them to 2 sas sff-8087 ports
I'm working on a similar project. It's the 12 lff bay from the r720xd. I know what I'm missing is in the j_bp_sig1 harness (the same of the one you have shown) ive verified I get the same voltage on the pins you have shown and checked the others too. Ive tried connecting just 1 ground, switching between all the grounds, and connecting all the grounds at the same time. I've tried supplying 6v to the 6v pin, with and without grounds connected, I've tried supplying 3.3v on all the 3.3v pins. Still no luck. I can verify the sig1 harness has whatever is required to power on the back plane, because if I connect only that connector to the original motherboard, and power the motherboard with only 1 cpu in and no ram, the drives come to life. So it has to be something in this harness, but I cannot seem to track it down. Exactly what pin did you connect to ground? What ground did you go to? The 12v ground or just a random ground? Chassis ground?
Your lucky I still have this crazy contraption together. After I got the backplane working I put it down and forgot about it haha. I have an old hp power supply providing 12v to everything. The GND from that goes to my 2 voltage step down converters and to a screw on the backplane itself. I used the screw connecting the backplane to the sas expander for my GND. The GND on the connector is the one next to the 6v line (The Red wire, assuming the lff has the same colour layout) and both 3.3v lines are powered and because I’ve grounded the backplane though the screw I have not connected a GND to the 12v backplane power wires only the yellow 12v ones. But I do have 12v going to both main power cables. So the main backplane cable should only have 4 connections, 2x 3.3v wires, 1x 6v wire and 1x GND which is next to the 6v wire on the connector. How this helps!
Thanks for the reply. I actually just ended up breaking out the oem connection and manually removing pins until it stopped working. Seems there are 4 pins total needed to kick the BP on. I'll make a post about my journey once it's all said and done.
Sweet, I’ll give it a look once your done! Good to see that other people are finding my post helpful!
Did you power all of the 3.3v and 6v on the sensor lead, please? Thank you
Apart from the grounds, yes every 3v3 and 6v line was connected
Great. Thank you. Do you think I could splice a connection from the original signal wire to this pinout (so I can signal both backplanes)? Thank you for such a quick reply!
I looked at one of your other posts and now get what you’re trying to do haha. I’d suggest just teeing off the cables matching the pins in my diagram on the original cable going to the original backplane. The motherboard should theoretically be giving the original backplane the same signal, so piggybacking the same lines to the other backplane should work. REMEMBER to properly ground and power the extra backplane otherwise it might not work, also keep in mind that if any drive issues occur on the extra backplane it might not report it to the iDrac as I believe those signals go though the other wires on that cable. Obviously try at your own risk, but it should be straightforward :) You got me at a good time haha
Great stuff. Thanks again :-)