Regarding hot-swap backplane and netraid 2m controller

[Corey Wilson_1]

We recently received possession of our tc4100.

We have the standard 8bay hot-swap back plane unit(not the duplexed option) I notice this back plane unit has one connection at the top, which connects to the scsi b onboard controller, and then it has the scsi3 end jumper cable. Can I remove one end of this jumper cable from the scsi3 port on the back plane and run a u160 cable from our netraid 2m card to this scsi3 port? I was told this is a dual controller back plane(yet I thought only the duplexed model was dual controller).

We have two 18gb scsi3 drives(for OS), and four 36gb scsci3 drives(for data). Initially we were going to install the two 18gb drives as non-hot swap and use the onboard controller and run raid1, and then run the 4x36gb's in the hot-swap back plane connected to netraid controller in raid-5. However, we were sent the slim profile hot-swap 18gb drives my mistake rather then 4616 model that comes with the mounting brackets for the 5.25" bays.

So I was thinking if possible I would use this as is to run the two 18gb drives in the back plane, as well as the 4x36 drives, and put each set to a separate controller, but because im not sure if this back plane unit will support that(if I remove one end of the jumper cable(that has a scsi 3 end) from the back plane.

Next I noticed that the symbios scsi controller doesn???t allow for hardware raid 1. And I want both sets of drives using hardware raid. So if this is in-fact a dual controller back plane, then I am planning on running the 2x18gb's to one channel on the netraid controller, and the 4x36gb's to other channel on the netraid controller. that way I can achieve my hardware raid1 and raid5 levels.

If this controller is NOT a dual-controller(which I just cant tell because of this jumper cable connected their and what its actually for) then I will order the 4616 drives, install them in the non-hot swap bay. I guess it would just be convenient to house them in the back plane so the option of replacing them without downtime is a possibility in the future.

So now that you know where Im coming from and what I want to do, I would appreciate if you could help me with first, is this back plane a dual controller, and do I enable the second controller by removing one end of the jumper cable from the back plane and then running a u160 connector with a scsi3 end from my netraid controller to that now available connector on the back plane? And do you agree on going for the hardware raid for both sets of drives?

Thanks so much for your help! I am very new to this newer hardware.

[CA660377 · Accepted solution]

The SCSI jumper cable installed default on the system makes the backplane one piece. So leaving this cable in place from the factory, will allow you to put all the drives in the hotswap backplane on one channel of the netraid controller. There is no advantage to splitting the backplane and using both channels of the netraid controller, as you only have on point of failure still. Hardware raid works much better than software. It's easier when drives fail as well.

One other note, the 2M controller you are using in this system needs to have a B at the end of the part number. If you are pulling this form another system, it will not work, and is not supported by HP.

[Corey Wilson_1]

thank you for your quick reply Theo, however I am still a little unclear as to your suggestion.

First off, we are using the 'B' model, as this was the raid card ordered with the system, so it is compatible per the sheets accompanying it detailing the compatbility issues.

So in other words, by unplugging one of the jumper ends, that will not allow me to split the back plane into two? For instance 2 of the available 8 bays be able to run on one controller, and the remaing 6 bays from that back plane on another controller? I need to get this clear so I know how to proceed.

I would like to be able to simply run both sets of drives from the netraid controller. So will this mean that I would be best off installing the 2x18GB OS disk drives in the non-hot swap bay under the cd-rom, and then connect them to them to one channel of the netraid controller, and then place the other 4x36gb data disks in the hot swap bay and connect the hot-swap bay to the second channel of the netraid controller?

I appologize for requiring the clarification, however I want to be sure I am approaching things correctly from the start.

Thanks again for your help.

[CA660377]

There isn't a need to split the backplane(remove the SCSI jumper cable), or install the HDD into the common tray locations. By leaving the SCSI jumper cable on, making the backplane basically one piece, you can connect this to the 2M controller, only using one of the two channels on the 2M. Leaving the other channel available for external storage if needed in the future. You will not get an advantage by splitting the backplanes(removing the SCSI jumper cable) and connecting each backplane to it's own channel from the 2M. You can create 2 logical drives, one will be the 2 18GB, and the other will be the 4 36GB.

[Corey Wilson_1]

so no performance advantage would be gained then by putting each disk set on its own controller channel? Okay, thanks for the reply.