I need some RAID assistance

thefisherman

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Hello gentlemen,
I currently have a RAID 5 with 4 WD caviar green 3tb off my onboard motherboard Intel controller. I would very much like to buy an internal card to expand to 8 drives. But I have NO idea what to look for in a card. I know I want internal with 2 SAS ports. But buffers and I should get a PICe card right? Any other features I should look for. Also and very important will I be able to simply add drives and change it to a RAID 6 without losing my data??
Thanks guys,
Fish
 
Solution
First start with a budget and find a controller within that price range. Onboard cache is always a good thing and just like your system memory, the more the better. 512MB of cache is usually a good start. The main feature you should look for is the RAID level(s) you will need. Other useful features are online RAID expansion (this allows you to increase the RAID size without rebuilding the array from scratch), online RAID migration (this allows you to change RAID levels), automatic rebuild, hot swappable (most controller are these days) and staggered spinup is a good to have.

You will not be able to extend the current RAID on the motherboard at the hardware level to the new controller. You will have to create a new, independent RAID...

Nothing_But_NAS

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First start with a budget and find a controller within that price range. Onboard cache is always a good thing and just like your system memory, the more the better. 512MB of cache is usually a good start. The main feature you should look for is the RAID level(s) you will need. Other useful features are online RAID expansion (this allows you to increase the RAID size without rebuilding the array from scratch), online RAID migration (this allows you to change RAID levels), automatic rebuild, hot swappable (most controller are these days) and staggered spinup is a good to have.

You will not be able to extend the current RAID on the motherboard at the hardware level to the new controller. You will have to create a new, independent RAID array. However, depending on your OS, you may be able to combine both RAID arrays into a single storage volume.
 
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thefisherman

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Thank you so much NAS that was all i needed to know. I think my plan of attack will be buy the controller get my new drives set up on the controller and then use RAID expansion to simply add my other drives to it after I've transferred the data. Thanks again these things aren't cheap I really wanted to make sure I got all i needed on the first go around. My budget is right around 400$ if you have any suggestions.
 

Nothing_But_NAS

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It might be difficult find a controller with 512MB cache within that price range. 128MB or even 64MB would still be fine considering you coming from an onboard controller (fake raid).

I am partial to LSI cards because they have always worked for me on Linux. The 926x controllers are good. You could go cheaper and continue using fake raid cards like the 9240 (these do not support RAID6). Those can be had for about $100 used. I've read good review about non-enterprise Acera and Adaptec controllers, so any of those would be fine as well. Your price may require you to make a decision between full RAID controllers and fake RAID controllers. Full RAID controller have dedicated CPU for parity calculation and does not use the system CPU. Fake RAID controller uses your system CPU to do some or all or the calculations. This will result in different performance between the two type of cards. If you have sufficient system CPU and your usage is modest (mostly data streaming or backup), a fake RAID controller would be just fine.
 

Nothing_But_NAS

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That looks like a decent controller. Highpoint's website has more details and this controller supports all the features I mentioned, even background initialization, which means your newly build array will be available immediately.

I did not mention HighPoint because I am very partial against them due to past bad experiences. Do some research before you buy. HighPoint is known to sell cheap cards that are big on features on paper, but rarely performs in the real world. Not sure how new this card is, but there don't seem to be any reviews available. The only manual available online is a basic installation guide. That is truly HighPoint as far as support goes.

One caution about hardware RAID is if your RAID controller fails or is no longer supported (ie, no driver for new OSes), your RAID array is recoverable only if you get the card from the same manufacturer with the same RAID logic (usually an identical card). This is where I got burnt by HighPoint really badly. They would not release new drivers for my card. I bought another card from HighPoint, the cheapest I could find since I only wanted to recover my data. Because it was a lower end card with different RAID logic, my data was still inaccessible. I did end up recovering my data, but with no help from HighPoint. I eventually switch over to software RAID to avoid dependency on a RAID controller (my NAS requirements are basic and don't need super speed). Even then, I got burnt by HighPoint again, but I won't bore you with that story.
 

thefisherman

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Thanks for the input ill absolutely take your advice. If you have had a bad experience with them it isn't worth it. Lord knows i don't want to be the first one writing a bad review. I was planing on using this card for a long time so i would rather go with quality. A lot of people online as well as yourself seem to like LSI so I think I'm going to go with:

http://store.lsi.com/store.cfm/MegaRAID_Controllers/6Gb_SAS_9271_RAID_Controllers/LSI00334/

I found it for 635 on this site:

http://www.avadirect.com/product_details_parts.asp?PRID=26149

Breaking the budget but in the long run i think the extra 200$ will be worth it.
Thanks again for all your help i really appreciate it man.
 

Nothing_But_NAS

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The 9271 is a great controller that I can definitely recommend. Check ebay for the controller. There is a lot of people pulling these controllers out of working servers. [strike]You should be able to find one for under $500[/strike]. The only thing you get from buying new is the warranty. Ask the seller the age of the card they are selling. I have seen situation where LSI honored the warranty of a resold controller.

**Edit**
I was looking at the 9260s on ebay. Those are also good controllers which support the features you want. The 9270s are over $500.
 

thefisherman

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Perfect ill do just that. Let me ask you one more question im going to run with windows 7 (64) on an ASUS Max 4 Extreme p68. Neither windows 7 or that motherboard is on their compatibility list. off the top of your head would you anticipate any problems or you think it would be prudent to ask their tech support? I mean they have every OS under the sun listed i cant imagine 7 would be the only one that isn't compatible.
 

Nothing_But_NAS

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I can't speak much for Windows 7, but there should be driver for it. Check the LSI support site. Last I checked for my controller, they had drivers for every Windows OS starting from XP. Your motherboard should be fine as well. Make sure the Motherboard BIOS is up-to-date and you should update the controller BIOS as well. If you cannot get into the LSI's webBIOS, make sure you have INT13 or INT19 (can't recall which) enabled in the motherboard's BIOS.
 

thefisherman

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Will do will do. I ended up calling LS I support and I have to say those guys are great. They said I should have no trouble just if I want to get good performance I should disable everything I'm not using. The help the IO flow. Couldn't ask for better tech support people definitely got my business. Thanks a lot for the suggestion.