Raid On MOBO or Seperate RAID - Performance Wise

[hardwarefish]

I need some expert advise regarding RAID.

If the MOBO already have feature for RAID and would it be efficient to get seperate RAID CARD? (does using internal seperate raid card will increase the performance of the drive?) or the RAID build in inthe MOBO sufficient enough. (Im building this for server purposes)

Second Question: Which raid would be the best Raid 1 or Raid 10 or Raid 5 (consider this server use for hosting purposes) - Does raid 1 good enough to protect data?

** For the MOBO: im planning to use: http://www.supermicro.com/products/motherboard/Xeon3000/3200/X7SBL-LN2.cfm (SINCE I WILL BE USING XEON x3330)
** RAID CARD im referring to: http://www.newegg.com/Product/Product.aspx?Item=N82E16816116041

Please give me detail answer

 

[mavroxur]

It all depends on what level of RAID you decide to implement. If you go with a 0,1, 10, 0+1, then your ICH9R would be sufficent. As far as a RAID5, 6, 50, or something along those lines, I would recommend a hardware RAID card, however, I would not recommend that card. The card you linked is not a very good card. It is a caching card, however, it only supports basic mirroring and striping. If you did a 5,6, 50, or something like that, a caching card will blow away an ICH9R hands down. RAID 1 is fault tolerant, as far as how much fault tolerance you have will depend on the number of disks in the array. a 2-way RAID 1 will allow 1 disk to fail. a 4-way RAID1 would allow 3 disks to fail (super tolerant, usually overkill). It also depends on your IO requirements. Normally for CASs we do a RAID5 for the data volume, and the OS resides on a RAID1. If you need higher performance, you can go to a RAID 50, however, not all controllers support certain nested RAID levels, and managing nested RAID levels can be tricky if you're not familiar with how they operate.

 

[hardwarefish]

Mavroxur, thank you for your great answer however i need to know. If we want to start do hosting - will raid 1 is sufficient?

Yes the card i showed is for RAID 1 and does using this raid card will improve performance? or the MOBO raid is good enough

 

[mavroxur]

It all depends on the level of redundancy and capacity you need. If you don't need much storage space, and want average redundancy, then a pair of drives in a RAID 1 would be sufficent. If you need lots of space (more than a pair of mirrored drives could provide) then you need to move to a RAID 5, or if the array will be really large (5 or more disks) and the data is critical, a RAID 6 would be even better. a RAID 5 array requires a minimum of 3 disks, and your capacity is the total minus 1 drive. A RAID 5 array can lose 1 disk and continue to function. a RAID 6 array requires a minimum of 4 disks. Your capacity would be the total minus 2 disks. A RAID 6 can tolerate losing any (2) disks in the array at any given time. A RAID 6 would be a good idea for, say, an array of 6 or more drives, several hundred GB or a few TB each or more, where good fault tolerance is required in a medium throughput application.


As far as your question regarding the card you mentioned. The card you linked, in a RAID 1 scenario, won't provide much speed benefit over the onboard ICH9R. Maybe a very minimal gain if anything. However, the main reason people go with a RAID card as opposed to an onboard RAID is that a lot of onboard RAID controllers don't support things like hot swap, hot spares, and online array rebuilding, which makes them useless in a business scenario that requires high availability of data. What's the point of having a hosted service, if you have to take down the server to rebuild an array after a failed drive, which might take hours for a large array?
In a RAID 5 scenario, the ICH9R would be blown away by a caching RAID card (not the one you linked though, since it doesn't even do RAID 5). The reason being that RAID 5/6 require a lot of processing power for the parity calculations involved, and hardware RAID cards have a RISC or ASIC calculation engine to handle this. I hope I was able to shed a little bit of light on this.