# Need some help with this question.



## Hanzolo (Jun 13, 2014)

So I've been taking a Computer Essentials course which I haven't been able to keep up with since I have been busy with other matters. Now that my excuse is out of the way, I've been stuck on this real world problem. What I've been having trouble with is implementing RAID. I understand that I would have everything I need to install a RAID controller but I don't know what else I would need to implement RAID/ if anything. If you could answer the questions and explain to me how you got the answers, I would be extremely grateful. 

Question:

You work as a PC technician for a boss who believes you are really bright and can solve just about any problem he throws at you. Folks in the company have complained one time too many that the ﬁle server downtime is just killing them, so he asks you to solve this problem. He wants you to ﬁgure out what hardware is needed to implement hardware RAID for fault tolerance. You check the ﬁle server’s conﬁguration and discover it has a single hard drive using a SATA connection with Windows Server 2012 installed. There are four empty bays in the computer case and four extra SATA power cords. You also discover an empty PCIe x4 slot on the motherboard. BIOS setup does not offer the option to conﬁgure RAID, but you think the slot might accommodate a RAID controller.

Complete the investigation and do the following:

1. Decide what hardware you must purchase and put a screenshot of the web pages showing the products and their cost into a document.

2. What levels of RAID does the RAID controller card support? Which RAID level is best to use? Print any important information in the RAID controller documentation that supports your decisions.


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## Nabarun (Jun 13, 2014)

These are very basic things every system administrator is supposed to know. Server downtime is not going to be solved by implementing RAID. First figure out what IS the source of the problem. If you do want to do a RAID array anyway, it will be best if you do a basic reading on the subject. You will need to know about OS, storage, filesystems, volume managers etc to properly implement a suitable RAID array to meet your needs. What will suit you depends on your requirements and budget, and it will be childish to make any kind of recommendation.

You will need more drives in addition to a RAID controller card. For redundancy of 1 drive there is RAID 1 and RAID 5. RAID 1 basically copies the exact same data to 2 drives, and the resulting array's read speed is a bit better but write speed a bit lower. RAID 5 needs at least 3 drives, where the parity is distributed across all the drives and has redundancy for 1 drive only, and you get effective storage space for 2 drives. But this uses the CPU to generate the parity in various implementations (like Solaris Volume Manager), so keep that in mind. RAID 6 is almost the same as RAID 5, except that it has redundancy for 2 drives. There are more complex arrays like RAID 1+0 and RAID 0+1 etc which require more drives. Do keep in mind that it is not recommended to run servers using consumer-grade drives, since they are not designed for 24x7 high usage like enterprise-grade ones, which have special capabilities.


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## TRWOV (Jun 13, 2014)

I think WS2012 already has software RAID support, isn't it? or is it just JBOD?

Anyway, you'd better read up on the RAID5/6 write hole issue although an UPS should take care of that.
http://www.raid-recovery-guide.com/raid5-write-hole.aspx


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