Confused with the Concept of Controller, Array, and RAID

[scott_417]

First we have the SCSI Controller. Now we have this RAID Controller.

1)Does this RAID controller just sit on the SCSI Controller? And there is a cable connects the RAID port to the Disk drive?

2)Before the RAID, the SCSI Controller controls the Disk Drive via a cable. Now with the RAID, does this cable and RAID's cable combined into one? or in two separate cables?

3)How does the disk array connect to the SCSI Controller, via the RAID port， or another cable, or just through one cable (RAID or not)?

4)Among the six Disks, if group them into 2 arrays, how is each array connected to the SCSI controller board? Through the RAID port, or another cable, or just through one cable (RAID or not)?


Thanks to help.

Scott

[Oleg Koroz · Accepted solution]

Hi Scott, seems you have dozen Questions in the day, all of them about SCSI /Array Configuration...etc, most of them are similar, sound like you trying to finish "School"
Can you bring together all your Ideas what you try to do? Study? Pre-Sale questions? Or you own Hardware? DL380 G4?

Do you have access to HP search tools; take a look for PDF files
http://h18004.www1.hp.com/products/servers/technology/whitepapers/index.html
http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual&locale=en_US&docIndexId=179911&taskId=101&prodTypeId=15351&prodSeriesId=397634
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00142272/c00142272.pdf
http://h18004.www1.hp.com/products/servers/platforms/index.html

BTW. You need to rate answers with some feedback if you understand or you need more info, some of your questions requires to gave you extended Explanation and thrown basic in ITRC could be not sufficient enough, I just encourage you to take a look over white Papers, technology Papers, User Guides and Installation Guides.

If you need PDF Info on the different Servers navigate HP HOME > Support & Troubleshooting > Servers > ProLiant/tc Series and HP BladeSystem Servers > HP ProLiant xx Servers > HP ProLiant xxxxx Server series > HP ProLiant xxxxx Gx Server series > manuals (guides, supplements, addendums, etc) or other self-help resources

[Riju Kurian]

Hello Scott
Let me answer your questions.You seem to have generic questions.

1)Does this RAID controller just sit on the SCSI Controller? And there is a cable connects the RAID port to the Disk drive?.
The RAID controller will sit in the PCI slot of the server and there is a cable(depending on SAC model's) which connects the RAID controller to the SCSI backplane if you have hotplug drives.

2)Before the RAID, the SCSI Controller controls the Disk Drive via a cable. Now with the RAID, does this cable and RAID's cable combined into one? or in two separate cables?
It again depends,on certain models the same SCSI point to point cable shipped with the server would help.On select models you will have to purchase specific SCSI cables.

3)How does the disk array connect to the SCSI Controller, via the RAID port or another cable, or just through one cable (RAID or not)?
Ambiguous question,because we need to know if you are making use of a Smart Array Controller(PCI card) to connect to the disk array. In any case the SCSI point to point cable is used.

4)Among the six Disks, if group them into 2 arrays, how is each array connected to the SCSI controller board? Through the RAID port, or another cable, or just through one cable (RAID or not)?
It again depends on the SCSI channel it is connected to.If you are making use of a SMART array controller there is no such worry.You can group the drives as 2 arrays and use them .

PS : Please also check what KOV has pasted as reference links.

[Ivan Ferreira]

Scott, you ask a lot of questions, and people helps you. The way to retribute the help is assigning points to the answers provided.

Please review your posts and assign points to the people that helped you.

Answers to your question:

1) RAID controller is a PCI adapter with SCSI technology. There may be a cable or a cabinet, which is connected by using a cable.

2) The cabling may differ, but you always need the cable to communicate with the controller.

3-4) There is no a RAID cable, the cable is the same SCSI cable. The difference is that you attach the cable to a RAID controller instead a common SCSI adapter.

[scott_417]

Many thanks and much appreciation for the help. Also like to thank you to let me know the "points" assignment issue. I did not know the way how this forum is operated--apolagized. On the other forums I have attended, the points are assigned automatically by the system. Nevertheless, I'll definitely take time to review and assign the points to all the current and past replies I've received.

So far folks out there have responded arduously to my tedious questions. Say thank you is not enough. But I really can not find better words than thank you, so I'll still say a thousand thank you, with the one reserved for future use.

Again, I'll take time to review and assign the points to all the replies I've received.

Scott