I'm looking at putting together a box using a tyan S2510 (or similar) motherboard. This is a dual p3, with u/160 onboard. I will be using 3 18 gig 10,000 rpm drives. My question is this: what will I need to do in order to setup raid 5? Will I need to purchase a seperate raid 5 controller, or will the onboard controller be able to handle it? I am hoping to be able to use a 1u case, so I would like to avoid using the raid 5 controller if at all possible.

If I do need a seperate controller card, does anyone know of a motherboard that has a u/160 raid 5 controller on board?

Thanks!

mpope,

From my understanding there are both software and hardware ways of performing RAID5. I believe Linux has some kernel modules that can perform RAID5 even with IDE hard drives.

However most people look for a hardware solution. They tend to work better and provide additional reliability.

Running RAID 5 with three hard disks I doubt would work. Plus most people who use RAID 5 also have hot swappable drives. Without hot swappable drives you loose the main benefit of using RAID.

If you want a 1u server, save your money and buy a big fat and fast single IDE drive.

Just my 5 cents input.

I read a linux book awhile back.
According to that book, people think software RAID is better than hardware RAID. One disadvantage about software RAID is the configuration part, where hardware RAID is like plug-n-play.

Please comment.

So there are two reasons to use RAID.

1) is for added reliability. if one hard drive fails, the system and storage system can remain running and active
2) for added performance. spreading the read/write load across multiple hard drives allows for quicker read/write access of files

Traditionally RAID has been SCSI based. However newer technology and the dramatic decrease in the price of IDE hard drives has allowed for IDE RAIDs.

With the next generation IDE controllers UDMA 100 (it might not be the proper term, but you know what I mean) the performance gain of RAID has been decreased or might not even be existent.

So the only real reason you would want to use RAID is for the added reliability. But it is my understanding that most software RAID configurations require the user to shut down power to the whole system, before replacing a hard drive. This defeats the whole purpose of an always available storage solution.

With newer hard drive detection mechanisms (like S.M.A.R.T.) shipping with hard drives, RAIDs role in high availability systems has decreased and is becoming obsolete.

However, I suppose it could be argued that software RAID solutions aren't dependent upon the implementation of new advances in IDE/hard drive technology. Basically you can use a new UDMA 100 controller with software raid but would have to wait for your hardware RAID manufacturer to produce a new hardware board. Theres my two cents.:)

Matt

Aloha

well first off I would go out to adaptec.com and read there raid info
then go to www.storagereview.com and read there site about raids drives etc....

clear some stuff up
IDE works but is cheaper not as fast does not multitask like SCSI is not close to scsi nor MTBF or seek time access etc.. scsi is superior
so
scsi over ide (lets not start the battle)

now hardware over soft raid
go with hardware if ya want it done correct
the cards ahve cache on them to help performance

raid is faster and more reliable (one or other or both)and is not disapearing from systems
RAID can be slower for some system performance and faster for others so read about raid and you will understand more

also SMART has nothing to do if your head fails a bearing fries or whatever
so the idea of a drive failing is getting less and less but it can still happen

Raid 5 will work just fine with 5 drives and is very common and you do not need hotswap drives although they can be nice and you do not loose the main benefit
the main benefit is data integrity and redundancy.
better to have data to rebuild than none at all


so not to be harsh on Mathewfong but he wants to run a server off dsl (came back and bit ya in the butt ;) ) sorry mathew had to throw that in meaning it with good humor ;) sorry if it is to harsh (mod if it is feel free)

We've been running software raid5 on IDE disks (linux) for close to a year now and it has performed adequately. However, as our traffic has increased beyond 4 hits/second, 5, 6.... NFS traffic is beginning to degrade performance.

After spending a couple days reading up at the awesome storagereview.com, our sysadmin has recommended we move to hardware raid5 on scsi disks for maximum scalability and long term performance.

Bottom line, software raid5 is fine until you get busy.

Some comments, just my 2c.

Originally posted by matthewfong
With the next generation IDE controllers UDMA 100 the performance gain of RAID has been decreased or might not even be existent.

No. What has the speed of the interface (IDE or SCSI) to do with the speed gain from a hardware RAID system distributing the load to serveral drives?

So the only real reason you would want to use RAID is for the added reliability. But it is my understanding that most software RAID configurations require the user to shut down power to the whole system, before replacing a hard drive. This defeats the whole purpose of an always available storage solution.

Agreed, that's the first reason why I wouldn't use software RAID, the second is it does degrade the performance due to the higher CPU load.

With newer hard drive detection mechanisms (like S.M.A.R.T.) shipping with hard drives, RAIDs role in high availability systems has decreased and is becoming obsolete.

Hm, do you really think so? I like the idea of SMART, but on a server system I would rely on a RAID5 plus hot swap.

Hardware RAID is usually (almost always) faster and more reliable than software RAID. With software RAID, the CPU must do all the RAID calculations but with a Hardware RAID card, it has it own processor to handle the math.

RAID will not always give you better performance/speed. RAID 5 is great for improving reliability (as it can still function if one drive fails and you can also have a spare installed to take over), but is slower on writes.

All S.M.A.R.T. technology does it help alert you to drive problems.

Hope that helps!