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What RAID is best for me

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  • NAS / RAID
  • Storage
Last response: in Storage
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March 6, 2011 1:08:19 AM

Hello,

I am learning about RAID and trying to figure out if it is for me and how to go about doing it. As well as what type of RAID to do.

System Specs:

BIOSTAR TF720 2+ - supports RAID 0, 1, 0+1, 5
3.2 GHZ AMD X2
8GB PC 6400

Drives:
ST980811AS (Storage)
WD10EADS-00L5B1 (W7 X86)
WD2500KS-00MJB0 (W7 X64)
WD5000KS-00MNB0 (Storage)

I also have a PCI card installed that has two 1.5gb/s SATA slots one of which my lite on DVD burner is plugged into.

The first problem I have is that my file structure is a mess. I need to be able to clean it up and not loose anything important. I have had these drives for years and they have all had multiple OS's installed on them. I want to get down to just one installation of W7 X64. Before I go too much further I should say that I use this computer more as a server and work horse. I do some web serving but mostly use it for file sharing within my network. Believe it or I do not have enough room to back everything up and they are all almost full.

Second problem is that I cannot add anymore drives. The board has 6 SATA slots but I can only use 4 in IDE mode which I did not know the difference when I first built the computer many years ago. Only once I turn on AHCI+RAID mode can I use the last two spaces.

Here is my idea please tell me if it will work. I am looking at picking up another drive (maybe even an SSD), disconnecting all the drives I have in it now, and installing a clean W7 X64 and enabling RAID. Then one by one plugging in the other drives and cleaning them up (including removing the OS's that they have on them). My question is can this be done relatively easily? And how do I make it work?

data integrity and preventing loss is key but speed is always nice.

Thank you!

More about : raid

March 6, 2011 11:02:28 PM

Update
ok I just bought Western Digital Caviar Green WD10EARS 1TB 5400 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive

I just learned that somehow in the last week my 32bit OS has stopped working and won't boot into it.

I know there is some talk about the green drives not being fast and not working for a drive to install the OS on. I had my OS on my 32mb cache 1TB green drive and it worked with out a problem. It may explain some of the media problems I have when playing them over the network but that is a different issue.

What I am thinking is removing all of the drives install the new drive setup the bios for the RAID and install W7x64. Then I can put in the other 1TB drive into my external case transfer all files I need over and wipe the drive. Put that one in the case and continue down the line until I have all the drives in. My question is can I setup the RAID with only one drive to start? Can I just add drives into the RAID like that? Please let me know if I am going about this the wrong way!

Would it be better from a performance standpoint if I use one of the other drives as the primary? I don't think so because I am going to use the RAID but thought I would ask.
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a b G Storage
March 7, 2011 12:16:52 PM

No, you must build the RAID array and then use it. You cannot add to it in this situation. However, I don't think RAID is for you.

imho you should buy an ssd. It can be a smallish one. Around 60GB. (edit: your only looking at about $100) Mostly just for the os. You had it right in your first post. Disconnect everything. Set your bios to ahci. Plug in the ssd and load win7. Then clean up your other drives. Ultimately, you should have a good backup or even two when you start playing like this. It might even be worthwhile purchasing some online space for a backup just in case.

Cleanup of windows drives is a pita. But it should be done.

You can put your os on a Green drive and it will work. Painfully. You can RAID 0 green drives and it will work slightly less painfully. But RAID is something which, imho, should be reserved for storage vaults such as nas and das boxes in your house.

Perhaps a das like the drobo is right for you. There are plenty other brands and I think the drobo is overpriced but I'm just sayin. Or, for me, a NAS is the way to go as I can serve files to every computer in the house from a central location.
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March 7, 2011 8:01:20 PM

I picked up the 1TB drive for dirt cheap that is why I could not pass it up. SSD drive is not out of the question but I cannot get myself to spend $100 on 60GB when I can buy 1TB for $30. More though I cannot convince my wife as she does not get the whole playing/working on the computer thing.

Plus this gives me some space to be able to back it up. Is it possible for me to just RAID the two 1TB drives and leave the others? If I RAID 0 the two TB drives will I still have 2TB of space? or at least close. If so what drives can/should I RAID together and which ones would not be beneficial to RAID?

I was reading that RAID 0 makes them much faster but is prone to disk errors. What does this mean? I cannot afford to loose information while I am working.

What is NAS? You have me interested. Is this something I can do and still use the computer or does it turn it into a server only? Will this work with my droid?

Would it be better if I loaded my OS onto WD5000KS-00MNB0 as it is not a green drive? It only has 16MB cache but I do not know how that plays into the operations of the OS. Then I would be able to use the TB drives for storage only (with RAID depending on your answer to the question above). If I RAID the TB drives will the "spin down" feature still work?

Thanks for the help
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a b G Storage
March 8, 2011 1:49:21 AM

RAID 0 takes two disks and spreads information across them both. That way you could theoretically read and write at twice the speed.
Pretend you have a 2 bit file. 1 bit goes to one drive and 1 bit to the other. Now, picture one drive failing. You lost everything because half a file is worthless.
Also, RAID 0 does not help with access time which is the big slow down with 5400rpm platters.
However, you could certainly do it. There is a slight hit in performance with your chipset on the biostar as well.


edit... NAS stands for network attached storage

The NAS is a separate computer dedicated to serving files. Mine is in the crawlspace/basement under the house. You plug it into a network switch and anything else plugged into that switch (ie a wireless router or an ethernet cable to your desktop) can access that server. Generally people build a home NAS out of an older, retired, computer. You can buy them fairly cheap in the form of a DNS 323 or a nicer one that I like is the hp 495. You usually get performance for price but before you buy something you should check google for some reviews.

The idea is that you have a low powered computer with a bunch of spinning drives somewhere in the house and (in my dream world) every other computer has a simple SSD for the OS and access to the NAS for files. Most NAS boxes have upNp support and various methods of transferring files/music/video, etc.

A DAS is a box which sits beside your computer and can also house all your spinning disks in some manner of RAID. It would connect via USB3 or Esata or something. They are usually cheaper and should be faster than a NAS but necessarily they are serving to one computer which is less than 2m away.
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March 8, 2011 11:23:28 PM

adampower thank you for the clarification. Is it common to have errors like this when using a RAID? or is it just the same as errors with drives when not using the RAID? What is the diff b/n RAID 0 and RAID 0+1? From what I have read they both work pretty much the same but 0+1 has more fault tolerance. Not sure what that means. Is it possible to only RAID two of the drives and leave the others independent? Taking that another step is it possible to have two RAID's? Not that I am really thinking of doing that just trying to understand how it works, this is all new to me. If I used RAID 0 for the 2 1TB drives what drive do you recommend I install the OS on? At this time I am not buying an SSD however much I would like to.

I looked into NAS a little last night. I think I really do that now its just that I also use the computer that is the NAS. from what I found (and I by no means spent a lot of time looking and am in no way an expert on NAS) the only feature I do not currently do is the backup to another computer. This is mostly because I do not have enough space to back stuff up. Which leads me to another rumor I have heard which is that using a RAID allows for some sort of ultra high compression for backups. Is this true or is it for only a certain type of RAID (which my board probably doesn't support)?

I have 4 other computers on my network and they all file share off of this one. Mostly just for media. However, they run XP and I have all the drives mapped and it is messy. My wife has a hard time learning how to use it (i.e. refuses). I was thinking with one large RAID I would only have to map one drive (using just the 2 1TB drives in the RAID would be enough)

Please let me know your thoughts!
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a b G Storage
March 9, 2011 12:26:20 AM

Hmmm. The RAID levels are pretty straightforward there is a good wiki article on them I think. Here's my brief.

0 - stripe, two or more disks in a volume where any one disk failure results in volume failure. Benefit is up read and write up to double (for 2 disk raid 0) the speed of one drive. 2 x 1tb drives creates a single 2tb volume (ie one letter drive)

1 - mirror, two drives which mirror one another for redundancy. Either disk can fail and the other will continue to act normally (ie no information loss). There is a slight performance hit due to the necessity to write everything twice. 2 x 1tb drives create a 1 tb volume

2, 3, 4 not used much.

5 - three or more drives where one drive is dedicated to parity information. One can figure out a simple algorithm which allows one drive to create a parity bit for either one or the other of the first two drives to fail. In this situation reads and writes can be faster but there is more cpu workload to figure out the parity bit. 3 x 1tb drives equals 2tb of information (the other 1tb is used for parity)

6 - like 5 but with two parity drives for more protection.


After that we get to double digits such as 10 or 50 or.. 0+1 which are combinations of the aforementioned RAID levels.

A 0 + 1 raid is at least four drives configured such that you have 2 drives striped in a RAID 0 which is mirrored (RAID 1) with another 2 drives which are striped. 4 x 1tb drives results in a 2tb raid. The benefit is that you have similar doubling of speed like a RAID 0 but you can survive any one drive failing because there is another identical RAID 0 mirror. There is some debate about 0+1, 1+0, 10 etc. but imho with 4 drives there is no difference. At 8 drives you can debate the benefits.

I don't know of any magical compression software except for things such as Acronis which have nothing to do with RAID.

If you can build an xp network you can likely figure out some simple RAID setups.

You can, certainly, have a two disks in a RAID 0 for your OS and another two drives in RAID 1 for your 'secure' data. Commonly one would raid 0 some 150 gb velociraptors and have a couple of green drives in raid 1 for storage.

Again SSDs have made this less relevant.

I found it cumbersome and somewhat uncomfortable having a RAID 0 running the OS on my main desktop. Bought a 1 tb cav black and used it until the ssd came along.

Upgrade to an ssd and win7 and your wife will be happy with the file sharing! Then she won't mind that you spent the money on your ssd.
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March 9, 2011 9:49:51 PM

That is the simplest best explanation I have seen yet! Thank you!!!!

If you don't mind let me run this by you as a solution to my rebuild.

1. Clean out the 500GB drive (WD5000KS-00MNB0) (somehow)

2. Remove all but the 500 GB drive and turn on AHCI+RAID

3. Install W7X64 onto the 500GB drive.

4. Install the 250GB drive (WD2500KS-00MJB0) and move any files I am keeping to the 500 GB drive. Then format the 250 GB drive. (I can even do this using my external enclosure then install it into the case)

5. Place 1 TB (WD10EADS-00L5B1) into external enclosure and somehow figure out how to get the files I need off of it and onto the other drives. (will have to use space on the drives in the other computers on my network) Then Format that drive.

6. Install both 1TB drives (WD10EADS-00L5B1 and WD10EARS). Using the RAID 0 make those appear as one drive which will increase the performance. - Will the "spin down" feature still work or should I try to ask WD that?

7. Then install the 80 GB ST980811AS

Please offer any thoughts/suggestions. This doesn't solve my backup problem, but it still leaves me better off then I am now. I will have to implement some sort of backup utility that backs up to another computer on the network. Know of a good one that compresses the hell out of the information?

Then I only have to map the RAID 0 drive to the other computers (and maybe the OS drive). Now how do I do that (I know how to map the drives I meant the RAID)? I am assuming the RAID is setup in the BIOS or using a Mobo utility? (I haven't gotten that far yet)

Just to confirm, the errors I have read about when using RAID are results of actual disk failures, correct? Not actually errors writing the information to the drive, that would cause corrupt data while using them?

Stupid question that I think the answer is no to. Can I leave the data on the 1TB drive and setup the RAID or does this process wipe out all the data on the drive already?

YOU HAVE BEEN A TREMENDOUS HELP, THANK YOU!!!!!!!!!!!
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a b G Storage
March 9, 2011 11:21:37 PM

Wow
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a b G Storage
March 10, 2011 1:27:09 AM

First, first, thing. Go to ncix.com and buy a 2tb green drive (ears) for 69.99. Hopefully you live in Canada. Everybody should. haha.

First thing I see is the EADS/EARS raid 0. EADS has 512b sectors and ears 4kb. hmmmph not sure what's going to happen or if one can force the eads to have... Gonna say NO. Can't be done. (watch how fast somebody proves me wrong).

Next thing I think is... why? If you do a fair amount of photoshop or video transcoding the RAID 0 might help a little but for serving files over a cifs/samba network a single drive can probably max things out. However, perhaps the best answer to the why is... because... it can be done and it's cool and therefore I want to do it. I can live with that answer

Okay so now the how...

As I said I don't think you can raid those particular 1tb drives. However, you could buy another ears? Or, better yet buy a couple of 640gb cav blacks or something your budget can handle.

Or, shelve the RAID idea until you retire this rig to being a NAS and follow the below procedure for cleaning up the mess. After that, everything else in your computing life will be easier.

You can change a bit in your registry which will allow you to go back into your bios and change from ide mode to ahci mode. I think. Here's the procedure. Write it down and try it.

type regedit into the little 'start, run, search,' thingy in win7.
Find HKEY_LOCAL_MACHINESystemCurrentControlSetServicesMsahci
It should be set to 1. Set it to 0 by right clicking and choosing modify.
Now close regedit... I think it saves automatically.

Reboot and enter bios where you change your hd setting from ide to ahci.

Windows SHOULD come up. If not, reboot and change it back to ide and cross your fingers. For future reference I think there are only two modes as far as win7 is concerned. AHCI or NOT. A 1 in the msachi register is for ide AND raid mode. A 0 is for AHCI mode. So, you should be able to change your bios to RAID mode without boot issues.



Okay, now we're in AHCI mode right?

So, plug in your new ears drive and build a nice, clean, easy to follow, file structure whilst copying everything dear to you onto this volume. Clear the 500gb drive first as I think this is your best drive.

Load win7 on the 500gb drive and proceed to clear the rest of your storage drives of windows junk and build yourself some nice file structures.

Now you have.. an se16 500gb boot disk, 2 x 1tb storage disks and an 80gb on the side. Right?

Your next purchase is a 2 or 3 tb green/lp drive and a nice little external usb or esata drive reader. Win7 backup compresses and works ok (and it's already paid for). Use the backup utility to store everything on your new backup drive.

Now you can save your pennies and buy some proper drives for your raid array. Even get them second hand. Get some raptors or some cav blacks. Or samsung f3s. Then you can play. Whatever you do you should put your boot partition on the raid 0 because it will help load win7.

Of course, ultimately, you will have to go to ssd when you build a new desktop for yourself.

What do you think? Luckily you can not raid the 1tb disks as you would need to find someplace to put 2 tb of information.

from your post:

"Just to confirm, the errors I have read about when using RAID are results of actual disk failures, correct? Not actually errors writing the information to the drive, that would cause corrupt data while using them?"

Correct. There is something called a write hole for raid 5s which has to do with power failures... etc. but. The danger with a striped array is that every drive will fail. If you stripe across two drives you have doubled your chance of failure. And 2tb of your life goes in the toilet.

The only real benefit to your raid 0 would be that there is only one volume to map.
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March 10, 2011 8:53:35 PM

I am in the "good" old US of A so that's a no dice on the Canada. I cannot spend $70 on another drive right now or else I would that's a great deal.

No offense but I hope someone does answer with how this can be done I was really looking forward to setting them up in a RAID. What would happen if I tried it anyways?

Not sure 100% what you mean by "video transcoding" but I have an idea and no I don't. I access the files from another computer and play them on that system. (would be great if I could find a way to play them on this machine and watch them on the other). However I have a feeling that drive speed does come into play with how well the file plays on the other machine, but most of it is how old those systems are. Even if it doesn't help I am going with "it can be done and it's cool and therefore I want to do it."

As for the cleaning if the RAID is out I think I am going to pull the drives completely out and install a new OS from boot, using AHCI so I can access the other two ports on the mobo. I get nervous when I have to go into the registry, plus my other OS's are so messed up this will force me to build a solid file structure with no chance of the other installs coming back to haunt me.

I'm glad I at least was able to figure out which drive was best for the install. I did notice you missed the 250 GB (WD2500KS-00MJB0) drive in your last post. I hope that doesn't change your answer (unless it means I can RAID).

I have a external enclosure that connects via USB that I can put the drives in. I don't like to use it for long term though. If you haven't figured out I am a little energy cautious and that thing keeps the drive spinning all the time.

"Now you can save your pennies and buy some proper drives for your raid array. Even get them second hand. Get some raptors or some cav blacks. Or samsung f3s. Then you can play. Whatever you do you should put your boot partition on the raid 0 because it will help load win7. "

Thanks for the advice but I think I will save the pennies for a new system with an SSD and a new quad core (or whatever is most reasonable for the $ at that point). The Disk space with my new drive should hold me for a while.

The only thing I have left to solve is how to make the multiple drives "user" friendly over the network; so my wife will stop emailing files to herself when she changes computers. I have some ideas of using folder shortcuts on one drive and only map one drive. Maybe she will stop being stubborn and figure out how to use it (not that I haven't shown her)

THANK YOU FOR YOUR HELP! and hopefully someone else can tell me if they have a way to RAID those two drives. I am starting the prep work on moving files around now but due to my work schedule am not going to have the time to truly do the rebuild until the end of the month.
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a b G Storage
March 10, 2011 9:45:56 PM

Is there a jumper on the back of your ears drive? I think you can remove that and have a go.

Something like unraid could help with the mismatched drives.. check here:

http://www.lime-technology.com/

Might help with a mismatched array BUT again this is a NAS OS. Perhaps you could run it embedded whilst still running win7? I know nothing of this.

I'm excited about the jumper thing though. I'd try it just for kicks.
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a b G Storage
March 10, 2011 9:47:32 PM

Transcoding is what my old q6600 machine tries to do with my wife's hd video to make it into mpeg2 format. Takes forever.
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March 10, 2011 10:14:42 PM

there are no jumpers on the back of the drive. I see where they can go but nothing there.

That unraid looks exactly like what I need. I will look into using that within W7 or something like that.

This looks like a software RAID more than a hardware/BIOS RAID (not sure of the proper terminology there maybe should use "normal")

Thanks
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a b G Storage
March 11, 2011 12:32:11 AM

Yes, anything we do will be 'software' raid even if the bios settings change. But a raid 0 is pretty light on the cpu.

Hardware raid requires a card which will calculate parity bits etc.

It seems I got my hopes up over nothing. Apparently there is some way to add a jumper which makes it emulate 512b sectors by starting at sector 64 or something BUT it is still a native 4kb drive. For some reason windows requires drives to present themselves as 512b?

Anyway, if the RAID does work it may work terribly slowly. You could still try it. I'm interested in the result.
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March 12, 2011 2:39:00 PM

So even if I do a software RAID it will be terribly slow? Now that I am turned onto software RAIDing it appears that W7 can do it. I don't usually like using windows for things like this, but are there any pro's/con's?

I do not want to use unRAID because that is an OS and i want to stick with W7. Maybe some day I will go with a NAS and then may use unRAID. I am still looking for a utility that works like that though. Something where it doesn't care what I put in it it just works. Please let me know if you have any suggestions.
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a b G Storage
March 12, 2011 6:13:05 PM

Windows software raid works fine. Speed should be fine if drives get along. The reason I think it will be slow is the sector size issue. If it works at all. I'm intrigued.

UnRaid is neat. But, as you say it should be saved for your nas.
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March 15, 2011 6:29:37 PM

Sorry I havn't replied in a while. I have been busy and researching all this stuff.

Would something like FlexRAID be what I need?

www.flexraid.com
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a b G Storage
March 15, 2011 8:18:46 PM

Looks cool. Never heard of it before. I think that could be exactly what you are looking for. Not sure about the linux / win xp or win7 issues.

A 'lightweight' raid that sits 'on top' of your file system. Perfect for something like what you are doing. Seems tailored more to protection than speed but both are important for your data.

I'm intrigued. Please let me know how it works, whatever you decide.
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