RAID

[MindFlare327]

I am getting twin Seagate Barracuda 7200.9 3Gb/s 160GB 7200 RPM 8MB Cache SATA 3.0Gb/s hard drives for my build. I plan on doing RAID. When it comes to RAID 0 and RAID 1, which is better? Suggestions?

 

[Pain]

Better for what?

Probably worth looking through this forum and reading some of the threads there.

 

[MindFlare327]

Well, It will be primarily gaming, but also some video and photo editing.
These are my specs.

Case : NZXT NEMESIS ELITE BLK Black 1.0 mm ALUMINUM ATX Mid Tower 400 WATT PS2 ATX 12V Power Supply http://www.newegg.com/product/product.asp?item=N82E16811146007

Motherboard : ASUS A8N-SLI Premium Socket 939 NVIDIA nForce4 SLI ATX AMD Motherboard
http://www.newegg.com/product/product.asp?item=N82E16813131540

Video Card : ASUS EAX1900XT/2DHTV/512 Radeon X1900XT 512MB 256-bit GDDR3 PCI Express x16
http://www.newegg.com/product/product.asp?item=N82E16814121554

Power Supply : Antec TRUEPOWERII TPII-550 ATX12V 550W Power Supply
http://www.newegg.com/product/product.asp?item=N82E16817103931

Processor : AMD Athlon 64 X2 4200+ Manchester 2000MHz HT 2 x 512KB L2 Cache Socket 939
http://www.newegg.com/product/product.asp?item=N82E16819103547

Memory : CORSAIR XMS 2GB (2 x 1GB) 184-Pin DDR SDRAM Unbuffered DDR 400 (PC 3200) Dual Channel Kit
http://www.newegg.com/product/product.asp?item=N82E16820145575

Removable Storage : Sabrent 52-in-1 USB 2.0 Internal Flash Memory Reader/Writer
http://www.newegg.com/product/product.asp?item=N82E16820300608

3.5 Floppy Drive : SONY Black 1.44MB 3.5" Internal Floppy Drive Model MPF920 Black - OEM
http://www.newegg.com/product/product.asp?item=N82E16821103116

Hard Drives : 2 Seagate Barracuda 7200.9 3Gb/s ST3160812AS 160GB 7200 RPM 8MB Cache SATA 3.0Gb/s - OEM
http://www.newegg.com/product/product.asp?item=N82E16822148103

Keyboard : Microsoft Comfort Curve 2000 B2L-00047 Black 104 Normal Keys 9 Function Keys USB Ergonomic Keyboard
http://www.newegg.com/product/product.asp?item=N82E16823109156

Monitor : SAMSUNG 740N-Black 17" 8ms LCD Monitor 300 cd/m2 600:1 0.264mm Pixel Pitch - Retail
http://www.newegg.com/product/product.asp?item=N82E16824001072

CD-RW/DVD-RW : 2 Lite-on SHW-160P6S04 16x8x16xDVD+RW / 16x6x16xDVD-RW / 48x24x48x CD-RW
http://www.newegg.com/product/product.asp?item=N82E16827106013

CPU Cooler : ZALMAN CNPS7000B-Cu LED 2 Ball Blue LED Light Cooling Fan - Retail
http://www.newegg.com/product/product.asp?item=N82E16835118119

Operating System : Microsoft Windows XP Pro w/Service Pack 2 OEM
http://www.newegg.com/product/product.asp?item=N82E16837102062

Surge Protector : Opti-UPS ES1000C 8 Outlet 700 Watt
http://www.newegg.com/product/product.asp?item=N82E16842107113

 

[Pain]

Yeah, but better for what, i.e. are you concerned about security or are you concerned about speed. Raid 0 and 1 are two completely different things, and are really only related because they contain the term RAID, which really doesn't even apply to Raid 0...it's more like AID.

Go read that forum I linked to, and especially the raid faq, which will probably answer your questions.

 

[MindFlare327]

well, I was concerned about increased performance as far as gaming goes. Looks to me like RAID 0 would be the way to go, but if one drive fails, they both will fail...so wouldn't I be better off just getting one larger HD instead of 2 smaller ones set with RAID 0? How much would the performance be increased?

 

[Pain]

The hard disk forum has several threads on the front page that talk about this subject. Take a peek there and you'll probably find the answers to help you make a decision.

There really is no perfect solution, and you have to decide for yourself what is most important to you, so go read those threads and see what other people are saying.

 

[MindFlare327]

thanks for the help.

 

[lcdguy]

Raid 0 - Stripes the data across multiple drives boost read/write speeds, downside is if one drive fails all the data is gone

Raid 1 - Mirrors Data, the speed is the same as on one drive but you total capacity is cut in 1/2.

Addtional Raid Levels that might interest you

Raid 5 - Striping+Parity uses striping and a parity bit to give you both perfmance and some degree of data redundancy, Downside you need a min of 3 disks and you lose one drive to parity

Raid 0+1 - total capacity is cut in half, you need a min of 4 disks can have up to 3 disks fail.

Raid 10 - like raid 0+1 only more advanced.

Personally i would drop the raid, get a seagate 7200.10 320GB drive, it's what i use and it's a 3.0GB drive with NCQ support

 

[Pain]

Raid 0+1 - total capacity is cut in half, you need a min of 4 disks can have up to 3 disks fail.

On the 3rd disk failure you lose all your data, so you can have 2 disks fail, right?

I'd also be sure to check the controller documenation to be sure it will be able to use the drive indepdantly before assuming you could have a disk from each array fail and still have a striped set operating.

 

[lcdguy]

sorry, ya 2 drives can fail.

 

[bliq]

You can have 2 disks fail in RAID 0+1 as long as they're both from the same RAID 0 part of the mirrorset.

If one drive fails from each of the two mirrors, you're hosed.

If you're really worried about data security and you want increased speed, go RAID 5.

But remember, a HDD MTBF is something like 300,000 hours. The chances are, you could have your machine on for 10 years and not suffer a failure. Reality is more like 3-5 years for a highly stressed server, and closer to 10 for a less stressed workstation. I have 3GB HDDs from more than a decade ago that are still working (though not in everyday use anymore)

 

[aristotelus]

I am always laughing when i see people suggesting that a raid 0 (striping data across multiple disks) is unsave for your data while the initial question is mostly in comparison with single drive.

Yes you will loose all your data if one of the drives fails within a raid 0 configuration..........

But the same goes for your single drive........



So comparing single drive to 2 popular and meaningfull raid configurations for home use, raid 0 and raid 1. (Dont even think about going raid 5, totally overkill for home usage) You will need atleast 3 drives for raid 5 and raid 5 is slower than raid 0 and raid 1. Raid 5 is only used in larger networks with high concurrent user counts that are mining data.

Compared to single drive:

raid 0 will give you faster read and write performance, much faster i might add. If one drive fails, all data is lost, but that also goes for your single drive. This is only stated to enlighten the reader about the difference within raid configurations, not in comparison to a single drive.

raid 1 will give you no hit on your write speeds but does slow down your read speed just a little bit, you do get 100% fault correction. If one drive fails you can keep working(you will be notified), replace the broken drive when you are ready for it and simply rebuild the array.

 

[bliq]

Raid 5 is about 30% faster than a single drive, about 35% faster than RAID 1 (due to controller overhead). RAID 0 is about 40-50% faster than a single drive. BTW "faster" is a relative term- some forms of RAID are faster at read, some are faster at write, some excel at both. I have about a decade of personal test experience in mid to high end server usage.

The primary factor you're not considering when looking at failure is that a single drive MTBF is about 300,000 hours. playing the averages, when you move to 2 drives, you cut MTBF in half. But 150,000 hours is still a really long time.

RAID 5 is indeed overkill for most home applications (like gaming or office productivity) but with the cost of drives as low as they are and built in support for RAID 5 + hot spare in many mainstream motherboards, it's not out of the question for sensitive applications- financials, telecommuters, and anyone else reliant on their computers and data for their livelihood (like me, though I run RAID 0 because playing the averages, I'll be fine since I upgrade about every two years)

BTW, RAID 5 is not only for datamining. There are many applications for RAID 5 in the enterprise. We use a huge 1.5TB RAID5 array (actually more like several RAID 0+5 arrays) as the docroot and another 5TB array as a content delivery system of my company's website. Many graphic artists I know use RAID5 becuse they need speed and redundancy as losing an image can represent days or weeks of lost work, missed deadlines, and lost contracts.

 

[aristotelus]

Are you sure about raid 5 being faster than raid 1?

I was always thaught it was not, and yes it is relative to reading or writing, i did take that into account.

Whether you have a decade of experience or not......we all still make mistakes sometimes......

I keep mixing the raid 0 and 1 up (which one is the stripe or the mirror)
I recently got reminded so for now i remember.......

And i have been a database man a long time (DB2 on AS/400 and Oracle on UNIX aswell as on NT clusters) ........so.......or i am getting rusty ( i do know how stripe or mirror works so not seniel yet) ..........or it was just not important enough to remember for some time....

Anyways, i do remember trading off raid configurations based on speed and durability..........


So I ask again.....are you sure?

 

[PCcashCow]

I may be wrong, but I know that many raid setup are only worth the effort when they are done on a controller that does not rely on native motherboard processing like onboard raid and sata channels do. Some low-end cards only offer controllers and channels, so be sure to consider the external card with decent chipsets like adaptec or lsi.

 

[Bosaka]

How much faster is Raid 10 vs Raid 5? In terms of random access and constant rate.

 

[misry]

since it looks like your a new egg kind of guy,

http://www.newegg.com/Product/Product.asp?Item=N82E16822136009

yes Virginia, they cost more. they also have 16M of cache and 1M MTBF. you read that right, 1,000,000 hours, they are near line drives. RAID 0 them and install XPPro x64 in 20 minutes.

 

[Pain]

I keep mixing the raid 0 and 1 up (which one is the stripe or the mirror)
I recently got reminded so for now i remember.......

Think of it that RAID 0 (zero) has no Redundancy.

I use RAID 5 at home, 2 servers in fact and mirror my data nightly between the 2 servers. Do the same thing at work actually. Both home and work have tape backups as well.

If you have critical data without a backup plan (not just a Redundant array) you are playing Russian Roulette.

I too think that thinking about a disk failure in a Raid 0 array is counter productive, becuase like I said, you need a backup plan. If you have a backup plan then who cares if a disk fails, weither you have a single disk or a strip set, doesn't matter. However, I don't think the speed increase is all that great for typical applications, and even in the best of circumstances you might get 40% increase tops, and usually it probably averages for the typical user at around 20% or less.

 

[aristotelus]

I may be wrong, but I know that many raid setup are only worth the effort when they are done on a controller that does not rely on native motherboard processing like onboard raid and sata channels do. Some low-end cards only offer controllers and channels, so be sure to consider the external card with decent chipsets like adaptec or lsi.

Most ASUS boards come with reasonable raid controllers.
Yes performance wise you could take it a step further using the dedicated controllers from adaptec.

But to say that raid configurations are only worth the effort when you use those controllers you are only looking at the performance aspect.
There will be a very noticeable speed jump from single drive to raid 0 on any raid controller...although it could be bigger......

But when we look at raid 1, that has become rather (or is becoming) important even in home use...........

Ever saved 80 Gigs of MP3, perfectly labeled etc. .............and have the single drive die on you?............Any raid controller that suports raid 1 will do just fine in that case.....

 

[Pain]

since it looks like your a new egg kind of guy,

http://www.newegg.com/Product/Product.asp?Item=N82E16822136009

yes Virginia, they cost more. they also have 16M of cache and 1M MTBF. you read that right, 1,000,000 hours, they are near line drives. RAID 0 them and install XPPro x64 in 20 minutes.

I had 3 of those in a 5 array, and just switched over to 5, 250G models of the RAID class disks in my main server at home.

 

[Dante_Jose_Cuervo]

This may be a bit of a stretch but has anyone thought of RAID 5EE as a possible solution for this guy? I mean yeah it's a lot more expensive to get a controller for this kind of RAID considering only top-level controllers use it but if he's concerned about data protection and throughput it might not be a bad idea if he can find a refurbished controller that supports RAID 5EE.

Again this might be a stretch and I might just be blowing steam but hey, just thought I'd throw that in for you guys.

 

[misry]

I had 3 of those in a 5 array, and just switched over to 5, 250G models of the RAID class disks in my main server at home.

Yeah, I wish I had known about them when I setup the files server at home but those Samsung 250's in 5 have got me to respect those drives as well.

the wd1600's were my first RAID0 at home.

 

[Pain]

This may be a bit of a stretch but has anyone thought of RAID 5EE as a possible solution for this guy? I mean yeah it's a lot more expensive to get a controller for this kind of RAID considering only top-level controllers use it but if he's concerned about data protection and throughput it might not be a bad idea if he can find a refurbished controller that supports RAID 5EE.

Again this might be a stretch and I might just be blowing steam but hey, just thought I'd throw that in for you guys.

Well, I'm participating in the discussion because it keeps me off the streets and out of the bars, at least until quiting time. But, my original intent was to point the guy at the proper forum and let him read the information already there. Now that we've thourough beaten this dead horse, who knows what he'll ultimately decide to do, but it appears that he hasn't been back.

I would image he will decide to use his onboard controller and the pair of disks he has now, and that means 0 or 1. 8) Course, he may just go all out and build a server. :twisted:

 

[chuckshissle]

I use raid 0 with two 74Gb raptors and I have one 300Gb caviar se to back it up. Yeah like they said raid 0 is fast and uses all the space but one failure of even one disk will corrupt the whole data. It's like having one hd, basically and it's not fault tolerant so it's raid 0 is not really a raid. But for me I have no worries since my important data is in the backup/storage disk and the os and games are in the raid array hd.

Here's more guide :

http://www.acnc.com/04_00.html

 

[lcdguy]

for anything other than raid 0 or 1 ie: 5, 6, 10, etc you should always use a DEDICATED HARDWARE raid card with an XOR processor onboard to calcualte parity since most consumer level boards do not have true HARDWARE RAID support. Something from Adaptec, 3Ware, LSI, Highpoint, etc.