questions about raid 5 - picking an adapter and such

[velvetpants]

I'm playing around with the idea of cleaning out all the small drives from my home server and replacing them with a huge raid array, so I could just have 1 centralized media storage/streaming server thingy.

But since I have very little experience with any raid setups bigger then 2 drive RAID0/1 on onboard controllers I'm gonna need some help.

Now I'm gonna be starting with maybe 5x 1TB drives, but I'd like to be able to add drives and expand without too much trouble. (I believe it's called Online Capacity Expansion)
Would I need some ultra pro 400$ raid controller just for that?
I don't really care about transfer speeds, it's just gonna be streaming movies and shit over a gigabit network.

Another thing. Is it gonna be any trouble if not all the drives are the same model?
I have a couple of 1TB seagate drives I'd like to keep using, but that model isn't manufactured any more so the rest would be a different type. They would all be the same size and all 7200RPM though.

I'm mostly just wondering how much money I'll have to shed out for the controller card.
Perhaps I don't even need one, maybe I could use some kind of software raid for this?
I'll probably be running debian or some type of nix on the server. Are there any software raid solutions for that that support OCE?

Any input on this matter from persons more knowledgeable then myselft would be highly appreciated.

 

[pugh]

Don't do software RAID. If you are not going to do the real thing then forget about it.

Have you checked newegg yet to get an idea on card prices ?

Also have you searched wiki or any other web page to educate yourself on RAID implementation ?

When I first inquired about RAID I searched and learned a lot from these forums and hardforum and 2cpu and xtremeforums...

After you have done some research I think you will be able to make a decision which route you take. It can be pricey. I dropped about 800+ for a Areca and 4 drive set up back in "08.

But I encourage you to search to get an understanding for your self.

 

[velvetpants]

Don't do software RAID. If you are not going to do the real thing then forget about it.

Have you checked newegg yet to get an idea on card prices ?

Also have you searched wiki or any other web page to educate yourself on RAID implementation ?

When I first inquired about RAID I searched and learned a lot from these forums and hardforum and 2cpu and xtremeforums...

After you have done some research I think you will be able to make a decision which route you take. It can be pricey. I dropped about 800+ for a Areca and 4 drive set up back in "08.

But I encourage you to search to get an understanding for your self.

Thanks for the reply.

Yea I've been checking on newegg and I see they are running from $70 and up to thousands of dollars.
I've also been reading up on the different raid levels and did a few google searches, I was just hoping someone here with more experience could point me in the right direction.

I really don't know what I'm supposed to be looking for in a controller card.

Like for an example. This relatively low priced rocketraid card http://www.newegg.com/Product/Produc...82E16816115050
vs this one http://www.newegg.com/Product/Produc...82E16816115085

What exactly would I get from the more expensive one that I don't get from the cheaper one?
Reliability? speed?

A lot of people say software raid is bad, but I've never seen any good reason to why it is bad, except for lower performance. But performance is not what I'm looking for though. I would be happy with 100MB/s I/O, I just need a huge storage partition with some redundancy and I thought raid5 would be perfect for that.

 

[pugh]

one card that comes to mind is the dell perc 5 i card. Great price and great performance.

You should be able to pick one up here in f/s trade forum or maybe try ebay.

Personally when I started toying with RAID. I learned from some of the pro's it was best to go hardware or don't do it at all. I had great experiences from using a AREA in RAID 0+1 ,5 and 0 at times. Solid card. Still costs around $280+ though.

Maybe I should ask you this, are you looking for peformance? Then RAID 0 would be your selection.

Redundancy ? RAID5 worked great for me on the ARECA 1210.

That first card you link looks to be software based. I would not waste the cash on it though. that second one is serious card though.

Whichever route you go, back up the data on the array.

What is it though you are looking to accomplish from using RAID?

 

[velvetpants]

I don't care about performance. If I can get the speed of a single modern 7200rpm hard drive then I'll be happy. Otherwise I would've gone for raid0 or raid10

I'm basically just looking for a huge storage partition with some redundancy for my fileserver/media server/seedbox.
Currently it's just filled with random drives of different sizes and it's just impossible to keep the files organized properly with that setup.

I'm not looking for any kind of pro setup, just a big storage pool. So I don't really see why software raid would be bad for this kind of thing.

 

[sub.mesa]

Keep in mind you need TLER-enabled disks to prevent them dropping out of the array whenever you encounter a bad sector, which prompts recovery for longer than 10 seconds, after which the RAID controller detaches and 'fails' that entire drive; not exactly safe IMO.

Make sure you have a full backup of your data, a RAID5 shouldn't be considered safe, especially with high-capacity disks that have a relative high Bit-Error-Rate, which prompts these bad/unreadable sectors in much higher frequency than older disks.

 

[pugh]

Ok .. Mind if I put my plug in for WHS then? It has got a nice following among enthusiasts. head over to wegotserved.com .

I have been running one since 2007-08. One huge storage pool for my media. Also hardforum.com has some thread in the storage forum with memebers discussing WHS.

I do exactly what you talk about with my many different mix of disks. No RAID needed.

http://www.microsoft.com/windows/products/winfamily/windowshomeserver/default.mspx

 

[velvetpants]

Keep in mind you need TLER-enabled disks to prevent them dropping out of the array whenever you encounter a bad sector, which prompts recovery for longer than 10 seconds, after which the RAID controller detaches and 'fails' that entire drive; not exactly safe IMO.

Make sure you have a full backup of your data, a RAID5 shouldn't be considered safe, especially with high-capacity disks that have a relative high Bit-Error-Rate, which prompts these bad/unreadable sectors in much higher frequency than older disks.

So if one drive fails the whole array has to go through some long rebuilding process while I sit there biting my nails hoping it doesn't find another bad sector before it finishes?
http://www.smallnetbuilder.com/nas/nas-features/31202-should-you-use-tler-drives-in-your-raid-nas
I googled tler and found that sounds risky.

But yes, backups, ofcourse. Won't be anything on the server that can't be replaced anyway, and if there is it will be in two other places too.

Those drives aren't cheap though. Can't raid controller be configured to not drop the drive so soon?
Maybe raid 6 would be better? 1 drive smaller in space but double the security.

Ok .. Mind if I put my plug in for WHS then? It has got a nice following among enthusiasts. head over to wegotserved.com .

I have been running one since 2007-08. One huge storage pool for my media. Also hardforum.com has some thread in the storage forum with memebers discussing WHS.

I do exactly what you talk about with my many different mix of disks. No RAID needed.

http://www.microsoft.com/windows/pro...r/default.mspx

Yeah I tried that thing, feels really clunky on my low end box.
I was never sure how the storage pool works though. I mean, what happens if one drive fails?
Isn't it essentially just jbod or something?

 

[RebateMonger]

(Re: WHS)Yeah I tried that thing, feels really clunky on my low end box.
I was never sure how the storage pool works though. I mean, what happens if one drive fails?
Isn't it essentially just jbod or something?

All WHS disks are partitioned with MBR and formatted NTFS. You can attach a WHS disk to any PC that can read NTFS and can read the files.

Also, if you've selected folder redundancy, WHS keeps copies of those folders on two different disks. If a disk fails, you tell WHS to "Remove" the disk and after it's finished its operations, you physically remove the disk and add a new disk to replace it or upsize it.

It's sort of JBOD with redundancy at a folder level (rather than at a disk level). A single disk failure is handled very differently than with JBOD.

Details on how it works:
http://www.microsoft.com/downloads/...cc-b85f-45fe-8c5c-f103c894a5e2&DisplayLang=en

I've installed WHS on eight-year-old PCs (adding a PCI SATA disk controller, a 1 TB SATA disk and 500 MB of memory) and I've never noticed anything laggy about it. It's not like you actually USE the server. Management is done by a management console running on a client PC.

 

[BigDH01]

I don't care about performance. If I can get the speed of a single modern 7200rpm hard drive then I'll be happy. Otherwise I would've gone for raid0 or raid10

I'm basically just looking for a huge storage partition with some redundancy for my fileserver/media server/seedbox.
Currently it's just filled with random drives of different sizes and it's just impossible to keep the files organized properly with that setup.

I'm not looking for any kind of pro setup, just a big storage pool. So I don't really see why software raid would be bad for this kind of thing.

I wouldn't want to do too many large drives in a RAID 5 array. I have used this:

http://www.newegg.com/Product/Produc...82E16816115057

which I've had decent luck with. I think it's basically an offload engine with some software. It doesn't have dedicated RAM, BBU, etc. However, it is fairly cheap and will do RAID 5 and 50. RAID 50 on this card is nice because you can split the ports and do two RAID 5 arrays with 4 drives each. With 8 drives, you lose two to parity, but you get a bit more redundancy. Similar to RAID 6, you can lose two drives as long but those drives have to be on different arrays. So not quite as reliable, but quite a bit cheaper than say a PERC 6i (which is what I would recommend if you want to go hardware RAID 6).

As far as the drives, I know people hate the WDC greens for this purpose because of TLER, but I've yet to see one drop from an array using the above card. It's been through two OCEs and the greens have not dropped (2 TB EARS). The only modification that was made was to change the idle time to 5 minutes using WDIDLE3. It could be the card, the usage patterns, what have you, but I haven't noticed the dropping issue.

I recently built a server to replace my old WHS server. It served me pretty well, but I'm starting to get a lot of data and doing data duplication was starting to get expensive. My current RAID setup is not quite as reliable, but I don't lose as many drives to redundancy. I was really on the fence about going with my current RAID setup or Vail, but chose to go Server 2008 with RAID for RAID 5 and also because I can use Server 2008 as a DC. This was before MS basically killed WHS for the home user by axing DE. I would have a hard time going WHS now simply because the underlying OS is quite old and there doesn't look to be a replacement on the horizon. And even though I understand it can, MS doesn't support making your WHS a DC or joining it to a domain (although a domain is probably overkill for home use).

I also have a test machine running in the other room running OpenSolaris. If you went software RAID, this would be the route I would choose. Setting up a zpool is dead simple, but you can't do an OCE like the above card can. You basically have to buy your drives a couple at a time, create a RAID array for every group, and then add the arrays together in a pool. This is not drastically different than what I'm doing now with RAID 50 though. Haven't directly benchmarked the two though. If you are not comfortable with Unix, it would probably be pretty easy to make an OpenSolaris guest VM on a Windows host OS. Managing zpools is really as easy as knowing a few commands for the CLI.