What RAID card do I need?

O

Obmas

Limp Gawd
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Jul 2, 2001
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I have just been buying new drives as I ran out of space over the years. But now all my SATA ports are full so I'm looking into raid cards that are expandable. It's been a long while since I looked at RAID and their associated cards and the terminology has me a bit confused with things like SAS and HBA. I've done some research and searched the forum but it's just not clicking in my head for some reason.

All I want is a RAID card that I can attach another RAID card to in a never ending daisy chain. I want to make one RAID 10 after another endlessly if possible. Will a basic Adaptec 1045 work for this? It says it supports up to 128 SATA or SAS devices. I just don't seem to understand how to go about connecting multiple cards or SATA devices after the initial 4 ports are filled from the first RAID 10 array.

What do I need to achieve my goal? Linux support is a plus but if windows is easier/cheaper then that is fine. The PC will run 24/7.


Thank you in advance and I apologize for my ignorance on the subject.
 
How many ports do you need? If you are doing software raid 10, you can just use something like the supermicro 8 port card for $100 assuming you don't need a ton of ports. Raid 0, 1, and 10 are not things you need hardware raid for since you aren't doing XOR calculations.
 
I would like hardware RAID. I plan on adding a new RAID 10 array (4x1TB) every 2 months or so. So that would be 4 ports for each RAID 10 array correct? The power at my home sucks and so power failure will happen.
 
longblock454 said:
Get a UPS and go with raid 6. Huge volumes(as in number of disks) in Raid 10 is a massive waste.
Click to expand...

+1

For that amount of disk you are looking at RAID6 gives you more storage as well as a 2 HD failure redundancy. However, a RAID6 hardware RAID card can cost a pretty penny.

You other option could be RAID 5 but that only gives you a 1 HD failure redundancy and from the sound of things that might not be a considerable option.

And a UPS a must in your case.
 
My concern with RAID 6 is that it will be slower then RAID 10 when moving large files around from one array to another. But after researching more it looks like the SAS connectors(SFF-8087) were the part I wasn't understanding. I see now how I can use a SFF-8087 to get 4 sata ports from a single SAS port. But I'm still not sure on how to connect an SAS port to another RAID card. I'm most likely going to end up buying at least a dozen drives in the next couple months. I'd rather just make a new array too for each bulk HDD purchase then rebuild an existing array each time.
 
Raid 6, on a decent controller, will end up not only using less disks for parity, but will also end up being faster than raid 0. Remember if you have 12 disks in raid 10, you are only going to get the throughput of 6 drives in raid 0, so maybe 600MB/s - 700MB/s. On a good controller, raid 6 can do more than that with 12 disks.
 
Obmas said:
My concern with RAID 6 is that it will be slower then RAID 10 when moving large files around from one array to another.
Click to expand...

Do you swap large files from one array to another as a hobby? A decent card and you'll never know the difference!
 
Good to know. I've only started having to move large files around recently and only understand RAID from research not practice.

So. How do I cheaply expand a basic RAID card to many drives? Does the SAS plug just connect directly to another card or backplanes only? Or?

Right now the Adaptec 5805 looks like my best bet.
 
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You cheaply expand a raid card to many drives with a SAS expander. See HP SAS Expander thread. You mention the Adaptec 1045, that's not a raid card, that's just an HBA (Host Bus Adapter) which is similar to attaching harddrives directly to the motherboard, except it has some intelligent features like staggered drive spin-up and hot plug support.

Adaptec 5805 doesn't appear to be working with SAS expanders in my testing, however the Adaptec 5085 does.

People often PM asking what's the best performing hardware RAID solution for the least amount of money, there's no question: Areca 1680X, Areca 1680LP or Areca 1680 combined with an HP SAS Expander = 32 ports of RAID6 for around $500 if you look out for open box deals or ebay. Only a few days ago I pointed a forum member to a 1680X + HP expander which he snagged for just over $500 total. If and when you need more than 32 drives, just add another expander for $175-$200 and you have 64 ports of RAID6.
 
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Thank you very much odditory. You cleared everything up for me and told me exactly what I wanted to know. Wish there had been a FAQ as I read that HP SAS thread but wasn't sure if it did what I wanted.
 
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