Duplex or Simplex

[Marvin Buckmaster]

I have a DL380 G3. I was wondering what the advantages are by changing the scsi configuration from simplex to duplex. Will I get better throughput using both channels? Will the array continue to function should one of the scsi channels fail?

Thanks!
Marvin

[Prashant (I am Back)]

Hi,

Please go through this post in same week. contain type os duples option and a image to explain also.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=565417

Regards,
Prashant S.

[Marvin Buckmaster]

I read the article you have pointed out. I am only using the built in Smart Array 5i controller. Is there any advantage to using both channels for one logical raid 5 partition? My SmartStart cd ver 6.30 did not recognize any drives when using the duplex configuration. I assumed its because it is an older version of SmartStart. The simplex configuration worked.

[Prashant (I am Back)]

Hi,

What option you looking for this i suppose

Integrated duplex - All internal hard drives are using the embedded Smart Array 5i Plus Controller that controls up to six hard drives through two SCSI buses:

For connection on server check image it will help you.

Regards,
Prashant S.

[Brian_Murdoch · Accepted solution]

Hi Marvin,

The answer to both of your questions is yes.

Simultaneous read/write using both channels and redundancy in terms of channels.

Be aware that the SCSI backplane is split into a 2-4 configuration as in Prashants attached image. This means that SCSI Id's 0 and 1 and on one channel and SCSI Id's 2,3,4,5 are on the other.

Therefore as an example if you had 4 disks and wanted best performance and redundancy with say 2 mirror sets, you would have to make the mirrors across the two channels e.g. SCSI ID0 and SCSI ID 2 as a pair and the SCSI ID1 and SCSI ID 3 as another pair. This would allow for failure of one channel. It's not ideal however for raid 5 as most of the drives are on one side (the 4 drive side) but its not bad. Of course you can also add a PCI raid controller to the system and use it to control either or both sides of the split backplane.

I hope this helps.

Brian

[Marvin Buckmaster]

I appreciate the responses from everyone! To summarize, I will create a mirror set for the system partition using the duplex configuration. I will do the same for the apps partition. Doing so will provide fault tolerance from a hard disk failure or a single channel failure on the scsi controller and better performance than a raid 5 or raid adg.

Thanks!