Multiple RAID Controllers

[suggsjc]

Can you have multiple RAID controllers in the same system? I'm looking at building a fileserver, and if I started with a 4 channel RAID controller, could I add another one later?

Along the same lines, if I were to start with say 4x400GB disks in a RAID5 system for 1.2TB, is there any (easy) way to expand the system?

Do many people use LVMs on top of RAID arrays? What are the pros and cons of doing it?

I'm just trying not to build my self into a corner. Basically, what is the best way to design a system that scales/expands well?

 

[majoravatar]

I'm not really sure why you think you need more than 1.2TB in the next few years (at which point your computer would be obsolete anyway and you should get all new components). However, it is indeed possible to scale up to multiple RAID controllers at once. A good example is the ASUS P5W DH Deluxe, which has three RAID controllers onboard. You should make sure that the controllers are compatible, just in case.

http://www.newegg.com/Product/Product.asp?Item=N82E16813131025

Hope it helps...

 

[blue68f100]

Adding multiple controllers are not a problem. Tomsnetworking did a review on raid controllers 6+ mo ago. The article covered 5-6 units. The raidcore bc 4852 allowed for expansion. The 8 port SATA was around $350 the last time I checked. It was one sweet unit for the price, cheap when compaired to others. Just make sure you have a hardware base raid. A lot less problems in the long run.

 

[suggsjc]

I had in my other post more of the details of why I will need the space. The most space consuming aspect is going to be the MythTV setup that I am going to build, and I am going to be hosting a couple of different project that will each need a decent amount of space...and it will continue to grow. Anyway, thanks for the response.

After doing more reading, here is a slightly different question. If a RAID controller say is has X channels, is that the number of drives that you can attach to it or can you have multiple drives/channel? If that is the case, then could you have an external drive enclose that connected the drives to the card? I'm just trying to grasp all of the different possibilities.

This post had some suggestions that I looked at. That is somewhat the path that I am going down.

 

[majoravatar]

Quick question - are you using SATA or SCSI?

Also, you may consider buying more dense hard drives. I'm not sure what particular drive you're considering now, but the Seagate Barracuda 7200.10 comes in a 750GB version. At newegg it only costs $409.99, which translates to $0.55 per gig. This is a bit more expensive than 400GB drives, but it's a thought. At 4x750GB you could have 2.25TB for the low low price of $1639.96 and it should still be blazing fast due to the perpendicular drive format.

Channels do mean drives. So a 4 channel RAID can only have 4 HDs. You can get a channel multiplier, but I'm not sure how this works.

 

[valis]

you can definately have more than one raid controller in the system, the box i'm building will have 3 8 port SATA controllers, highpoint rocketraid 2320 cards and the cards have the ability to span the array across multiple cards.

when all is said and done this box will have 20+ drives with over 10 terabytes of storage, i'll be posting more info when i get the last bits of hardware together.

Valis

 

[suggsjc]

Sorry, the details of what I am looking at are in the other post. I am 90%+ sure that I am going SATA. The price/performance is so much better.

Yeah, I'm looking into how the whole channel multiplier technology works. If anyone knows, then feel free to help us out

But from this product it looks like you could use this to make 5 disks appear as one...so for a 4 port controller, you could theoretically connect 20 drives? Anyone done this? Is that correct?

Another detail is that I am going to be running linux, so driver support is an issue.

 

[suggsjc]

...when all is said and done this box will have 20+ drives with over 10 terabytes of storage...

Is it going to start out with all of the drives or expand over time?

The reason I ask, is how do you plan for future expansion? If you started with a single card and (example purposes) 8x100Gb drives but needed to add an additional card and 8 drives. First, would the new drives have to be 100Gb or could they be larger? Second, can the additional drives be added "on the fly" and be incorporated into the overall array?

 

[valis]

...when all is said and done this box will have 20+ drives with over 10 terabytes of storage...

Is it going to start out with all of the drives or expand over time?

The reason I ask, is how do you plan for future expansion? If you started with a single card and (example purposes) 8x100Gb drives but needed to add an additional card and 8 drives. First, would the new drives have to be 100Gb or could they be larger? Second, can the additional drives be added "on the fly" and be incorporated into the overall array?

it's going to start with 4 500 gig drives and one 8 port controller. i made sure that the mobo i got would be able to handle 3 of the 8 port controllers down the road, and the case i have is a 12u rackmount case with enough room for 26 drives total. gotta plan ahead

the cards have the capability to add a new drive into the array, and also the ability to span the array across multiple cards. so yes, but it depends on your controller, the one i'm getting is the highpoint rocketraid 2320

 

[suggsjc]

Just for reference, what mobo and case are you using?

I'm also going to assume that since you are planning on going to 20+ drives you are using 500GB drives over the 750GB ones due to cost/GB instead of data density.

Sorry for all the questions, but I know you've probably done your research/homework, and since it looks like we are building similar systems I'm just trying to see what all information went into the decision process.

 

[valis]

Just for reference, what mobo and case are you using?

I'm also going to assume that since you are planning on going to 20+ drives you are using 500GB drives over the 750GB ones due to cost/GB instead of data density.

Sorry for all the questions, but I know you've probably done your research/homework, and since it looks like we are building similar systems I'm just trying to see what all information went into the decision process.

no problem, i was initially looking for a board with the capability to run 4 of those cards, but the only one that looked up to the task is the gigabyte g8-an-sli quad royal, which toms and anandtech both reviewed, but which is also nigh on impossible to actually procure.
so settled on one that would be able to run three of the cards (the cards run at pci-e 4x, and are compatable with x8 and x16 slots)
processor speed wasn't an important factor, since the cards i've already mentioned have hardware controllers and for the most time this box will only be sitting and serving files over a LAN, the mobo is the a8-n32-sli from asus.

the case i got lucky on, since it's not very easy to find a case that'll hold 20 or so drives, i found a 12u rackmount (with the optional wheels) on ebay for 150 including 70 for shipping and handling which really wasn't all that much more expensive than a regular case, when i get home i can respond later with the actual item information

 

[rippleyaliens]

Sure you can use multiple raid controllers.

For sata, i would look at 3ware, they have 16 port cards. Getting E-Sata is straight forward, just kinda pricey.
I have seen some servers with 3x 3ware 16 port cards. But had to have a Custom external port made, that went to rack mount external Sata racks. LOTS of custom sata cables , very expensive, but it is indeed doable.


i myself have a 2 raid cards in my system, a lsi scsi, and a lsi sata. ON top of that, the system i have came with onboard scsi raid. system sees them all, 1 array is raw storage, the other, raw speed.

 

[suggsjc]

1 array is raw storage, the other, raw speed.

HDD- 7x36gb 15k scsi LSI 320-1 raid card
HDD2 6x200 Sata LSI 150-6 card

So which one is which?

 

[rippleyaliens]

My 7x36 gb 15k is my os, and that my friends is striped. (huge risk).
But i also run win2k3 server. My user profiles are on my 6x200 gb drive (raid 5- Slower than dirt).. but protected.
IN last year only had 1 issue, but mostly me installing software and got too cluttered.
Next project is gonna rock..
2gb fibre channel, connected to a 14 drive dell 660f. so a 14 drive array, with 256mb cache+ Dedicated IO engine. And 6x 300 gb sata drives.
Now i just need a Core 2 duo, MB, with PCI-x slots. HINT, anyone know of any such animal????

Reason--, i run ALOT of vmware. I do tons of p2v, so i need something REALLY fast disk wise. I once tried on my raid, 5, it took like 3-4 TIMES the time to do specific things. i will never go back to onboard controllers, other than cd/dvd. They are getting better, but i am spoiled on enterprise type storage. YAh it costs, but then again, i have had the drives for over 2 years. PAid $50 a drive, 2 years ago, and a external compaq u320 rack for $100 on ebay. Raid card $100 on ebay. The 6x 200 gb sata were $89 ea, 1 year ago, the lsi 150-6 cost me the most, $300, only reason i bought that was that it is a pci-x card, and i have pci-x slot on my system. Max transit.