PE 4600: Splitting backplane - daughter card, please help!

Karthik Viswanathan vkaru at
Fri Oct 17 12:53:01 CDT 2003

>Matt, Jessica,
>Thanks for your reply.
>Matt, I already have the system with the specification I had mentioned. I 
>wanted to add the daughter card to it to get 2x4 configuration (not 2x8 as 
>u corrected !)
>I dont want to set the two 146G hard disk in a raid setup since I have 
>only two 146G hard disk and cannot afford to lose half by setting in raid 
>1, also not ready to take risk of putting in Raid 0.
>So as far as I understood from jessica and your message is, all I have to 
>do is get a daughter card, spit the backplane and fix the 3x18G hard disk 
>to one array and set it in RAID 5 and fix the 2x146G hard disk to other 
>array (without any raid setup).
>And as far as the cabling goes, There should be two SCSI cables running to 
>the backplane from the system board, one for the first array(18G) and 
>other for second array(146G). Also there should be a cable running from 
>the perc3/dc card to the 18G array for setting in RAID 5. Did I understand 
>As I had mentioned earlier, there is a tape drive attached and I guess it 
>is a SCSI drive. If so, how can I connect the SCSI cable to this. I would 
>prefer to keep this in the same channel as the 146G hard disk is. Is it 
>Tape device attached:
>1  6U103   Tape Backup Unit, 160GB, Full Height, Internal, SDLT-320, V1
>Thanks again for your help
>At 12:19 PM 10/17/2003, you wrote:
>> > PE 4600 (system spec given below):
>> > I am planning to add a daughter card to split the backplane to 2x8.
>>2x4 instead of 1x8, yes.
>> > With this I was told I will be able to setup two arrays separate for
>> > each channel in RAID. I wanted to put 3x18G 10K hard disk in one array
>> > and in another two separate 146G hard disk containers. The main purpose
>> > of this is to get a better computational performance with the 3x18G 10K
>> > hard disk array and use the separate 146 hard disks for file storage. I
>> > would like to know if I am in the correct path or am I doing something
>> > wrong?
>>Looks good so far.
>> > Also I was wondering will my PE 4600 will have two SCSI channels so that
>> > I can put the two arrays in different channel.
>>Yes, it has 2 SCSI channels, or 2 RAID channels, or one SCSI channel and
>>one RAID channel, however you wish.
>> > If so I want to know if this can be done with bios setup or does it
>> > require any physical connections or cabling to be done.
>>Yes, it is done through BIOS setup, and you've got to have the cables
>>right.  There are 2 68-pin wide SCSI connectors on the motherboard, and 2
>>short cables running from those to the SCSI backplane (when in split
>>backplane mode with the daughtercard), one cable to each side of the
>>backplane, and each side has 4 disks.
>> > I am confused with the connection between SCSI and RAID controller so if
>> > you could help me understand better it would be great.
>>The RAID controller and the SCSI controller are really inter-related -
>>they both use the same aic7xxx SCSI chip and connectors, and you can
>>configure each channel for either SCSI mode or RAID mode.
>>For the rest, you really need to discuss with a Systems Consultant.  Your
>>salesperson can assist.
>> > 1  60EPW  Printed Wiring Assy, Backplane, Jaguar, 1X8, ULT3, Slide
>>This is the SCSI backplane.  You aren't ordering the daughtercard to make
>>it a 2x4 split backplane with this config right now.
>> > 1  9M912   Assembly, Card (Circuit), PERC3-DC, INTEL-BE
>>This is an add-in PERC3/DC RAID card, not the onboard RAID I believe.  Is
>>that what you want?  This card does have 2 channels also, so you can have
>>your 146GB disks on one channel and your other disks on the second
>>channel, both sides connected to the backplane.
>> > 2  4R318   Hard Drive, 146GB, SCSI (Small Computer Systems Interface), 
>> U320, 10K, 80P, FJT
>> > 1  1M214   Assembly, Cable, Twisted Pair, Hard Drive, 2DROP, Enclosure
>>This is the cable running from your add-in RAID card to the enclosure,
>>with 2 disks attached to it.  But it's only one cable, you need 2 do to
>>the split backplane thing.
>>You should consult with your Systems Consultant, this doesn't quite look
>>like what you indicate you want.  You need the daughtercard, and may not
>>need the add-in PERC3/DC card - that's entirely up to you.
>>Matt Domsch
>>Sr. Software Engineer, Lead Engineer
>>Dell Linux Solutions
>>Linux on Dell mailing lists @
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