What is Zero Channel Raid? Facts vs. Concepts?

EbizGuy

Server+ is one of the toughest exams to find good study materials for.

1) Can anyone explain to me what Zero Channel Raid (ZCR) is?


2) How much effort should I spend memorizing facts instead of concepts? For example, should I memorize cable lenghs, Operating System minimum hardware requirements, processor slots and sockets and processer specs, switches for dos commands or just the commands themselves? Switches for shutdown commands for just the commands? The colors and order of wiring inside a Cat5 cable? What each counter and object means in performance logs and alerts? The differences between SNMP 1, 2 and 3? Should I memorize all 15 IRQ's? PIO modes? Should I memorize the speeds of all the different type of backup tapes, and the standards for each type? For example, Travan alone has 7 different standards on section 8-8 of my course technology book, each having its own capacity to memorize.... The voltage of different types of processers... I am tired of spending time memorizing usless numerical facts.

EbizGuy

P.S. Should I memorize what each pin does in a SATA cable...?

Fogelsville23@aol.com

sprkymrk

For starters, have you looked at the CompTIA Server+ objectives? They are pretty detailed in what you should know going into the exam:

http://certification.comptia.org/resources/objectives.aspx

Just fill in your name and email address on the above link, select Server+, and you can download a 14 page PDF detailing what you need to know.

Not having taken the test myself, that's all the advice I can offer. Good luck though.

Plantwiz

Start with the Objectives as provided in the link above.

As far as memorizing pinouts...not likely to be that specific, but it's also not going to take you weeks to learn it either. So it won't hurt you to know it.


For ZCR:
http://www.cdrinfo.com/Sections/News/Details.aspx?NewsId=12739

http://www.smartcomputing.com/editorial/dictionary/detail.asp?guid=&searchtype=&DicID=10886&RefType=Dictionary

http://www.intel.com/support/motherboards/server/n440bx/sb/cs-014885.htm

supertechCETma

modular RAID on motherboard (MROMB) - functionality is broken into two modules: the HBA providing the I/O processor (IOP), and the motherboard providing the I/O controller (IOC). The IOP is responsible for all of the RAID intelligence, whereas the IOC is responsible for communication to the disk drives.

MROMB requires a new addition to the system in the form of circuitry that ties the IOP and the IOC together. There is no official industry standard for this mechanism, but a de facto standard has emerged, known as RAIDIOS.

RAIDIOS stands for RAID I/O steering and performs two basic functions. First, it provides a method to reroute interrupts generated by the IOC. When the MROMB card is present, IOC interrupts go to the IOP, and when they're not present, the interrupts go to the motherboard's interrupt controller.

The previous name for this type of system was zero-channel RAID, or ZCR. The ZCR method for doing what RAIDIOS does for MROMB was known as SCSI Interrupt Steering Logic (SISL) and is now basically a subset of RAIDIOS. A few ZCR products were available a few years ago, but they suffered from technical problems now resolved by RAIDIOS.

ZCR systems failed to totally hide the IOC from the host, instead leaving it up to the end user to make sure he didn't enable certain BIOS settings or load certain device drivers. If the end user forgot to do this, the IOC would be the source of conflict between the ZCR card and a host application. As a result, ZCR quickly gained a negative reputation.

MROMB doesn't suffer from these problems, but there are still specific disadvantages and advantages of MROMB as compared with a standard all-in-one intelligent RAID card. If you are considering MROMB, you shouldn't let previous experiences or rumors of ZCR problems to play a part in your decision, since MROMB is an evolutionary step of ZCR.