cheap raid storage

BSD

What is this storage?
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Jul 10, 2004
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I'm looking to get the most storage I can for cheap, including the ability to connect the storage (likely with SATA expansion card), using a raid (on linux of course - so it can be a software raid). I just need lots of storage for cheap, and using a raid (5 probably) should ensure all the necessary reliability. There is a lot of 8 ~250Gb drives on ebay right now, and something like that would be awesome for me, but I have a feeling it will go for well over 200 (and I'd like to spend less than that). Any ideas on cutting corners are welcome.
 

BSD

What is this storage?
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Oh my, look at my register time/post number (heh, just had to say).
 

Bozo

Storage? I am Storage!
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If you want to put 8 hard drives in a RAID 5 setup. you are going to need an expensive RAID controller. Most of the cheap software RAID controllers only do 2 to 4 drives. I don't believ any motherboard RAID controllers can do more than 4 either.
But maybe someone else here has a better answer for you.

Bozo :joker:
 

BSD

What is this storage?
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I mean more like 4-6 HDs. What about using a combination of the mobo controller and a cheap pci controller?
 

ddrueding

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In Linux, a true software RAID can be made of any drives on any controller. Just add drives via the on-board connectors and when you run out, get an add-on controller. What hardware are you starting with?

I don't know about used drives (I don't trust them), but 500GB used to be the best GB/$ ratio...might be the 750GB drives by now.
 

BSD

What is this storage?
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Doesn't using 500GB drives diminish your GB/$ ratio in raid 5, though? (N-1)S where N = number of drives and S = smallest drive...
 

ddrueding

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Depends on the number of drives. Also don't forget to factor in the cost of additional SATA/PATA ports and of an eventual larger power supply. Check my sig.
 

P5-133XL

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I'd go for bigger drives and fewer of them. There are several reasons -- The cost of additional SATA/PATA ports; The unreliability of PATA power Y-splitters (my personal pet peeve) or the difficulty of getting enough SATA power connectors; The size of the case to fit large quantities of drives and the difficulty of getting reasonable length cable runs to each drive; Fewer drives, means less drive density so it is easier to keep them cool and thereby, more reliability. More drives also means it is more likely to experience a drive failure assuming they all have the same likelihood of failure.

The two benefit of having more drives is that you waste less space and you get faster STR (because the drives are theoretically read in parallel). For Raid-5 you will always waste one drive of space for the parity bits. On the other hand, right now 500GB drives are significantly less expensive per GB than 250GB drives so, depending on the economics, you may waste more space but still cost less for the same usable space.

I too would avoid used drives!
 

BSD

What is this storage?
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so you'd recommend something like 4 500gigs? (And in that case, 500gigs seems like a lot to waste in a raid of 2TB...)
 

P5-133XL

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so you'd recommend something like 4 500gigs? (And in that case, 500gigs seems like a lot to waste in a raid of 2TB...)

If it is cheaper, then it is not a waste: Compare prices between four 500GB and seven 250GB (1.5TB of useful space) or five 500GB as compared to nine 250GB (2TB useful space). As long as the price was even close, then yes I would chose the 4 drive setup over 8 drives for all the reasons listed above.

I went to Newegg and looked at prices as an example using just the cheapest new WD PATA drives the 500GB is $99.99 x5=$500 and the 250GB is $64.99 x9 = $584. As you can see, in this case it is cheaper to get 2TB of usable space using the 500GB drives and the same applies to the 1.5TB setup.

You are looking at the space as wasted. It is not! Rather is is simply the overhead needed to get you a single drive failure redundancy. If that is not worth it to you, then you can always do raid-0 or JBOD.
 

Fushigi

Storage Is My Life
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Also, as long as the RAID card supports it you can add additional 500GB drives over time to bump the array's capacity. And 5 drives will consume less power & generate less heat & noise than 9.

If I were building an array, I'd go with mirrored TB disks and add a second mirror when I needed more. Better reliability (can lose half the disks w/o losing data) and grow as needed. Or add two more & convert from mirror to RAID5. 4 drives w/3TB available capacity.

That said, my current preference is to not use disk protection and to instead copy data to other PCs in my network. My workstation has a 500GB disk. I put another 500GB disk in a PC in the basement and periodically I back up to it. While there is a window of opportunity for losing data, it's relatively small and I only have to buy capacity as needed. There's also no messing around with RAID drives and the complexities they add to a workstation. And if my PC's PSU goes wild & fries everything int he chassis my data is still safe on the other system.
 
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