Time for RAID

theycallmebruce · Post by **theycallmebruce** » Sun Dec 16, 2007 8:06 pm

Hey all.

So, my nice quiet Samsung 500GB drive starting making some very unfriendly noises on the weekend. I immediately turned off the PC and purchased a new drive from my local PC store (400GB Samsung, the largest they had in stock) and ghosted all my data. Luckily it was mostly intact, and after a reinstall of Windows all is working again.

I don't want this happening again though, so I think it's time for me to setup a RAID1. I have several options here:

1) Use Windows XP built in software RAID after converting to "dynamic disks"
2) Use cheapo fakeraid built into motherboard chipset (ICH6R)
3) Bite the bullet and fork out $$ for a real hardware RAID card like a 3ware or similar.

I haven't used RAID under Windows before, and I'm not sure what the best way to go is. If money was no object I'd buy a decent RAID card in a second. However, if 1 or 2 is a reasonable option I'll probably stick with one of those.

I guess what I'm after is more detail on the implementation of Windows built-in software RAID1 and in the ICH6R. In particular:

- Detecting disk problems. How good is Windows software RAID at detecting this, and how does it inform you of errors? How about the ICH6R chipset?
- Portability. If I set up RAID1 with the ICH6R, will I be able to access my data in another machine without ICH6R (if for example my board dies)? How about with Windows software RAID1?
- Performance. Does Windows software RAID1 or ICH6R take advantage of the fact that there are two copies of data to improve read performance?
- Any other limitations / caveats I haven't considered here?

Thanks.

PopCorn · Post by **PopCorn** » Sun Dec 16, 2007 8:22 pm

well if a true hardware raid is pretty much out of the question, then I'd go with the raid on your MoBo, because its a mix of hardware raid and software raid, (ie theres a chip on you MoBo that does the raid , that uses alittle cpu power but not much). With pure software raid, it uses alittle more cpu, is harder to configure most of the time, and normally alittle slower to, ps dont be fooled by some "hardware raid" cards, there merely a card thats software based and are pretty much the same as if using the raid on your MoBo, you can normally tell because they will be less $$ and there will only be like 2 or 3 chips on the board, but I'm not a raid expert either so someone my correct me

theycallmebruce · Post by **theycallmebruce** » Sun Dec 16, 2007 8:44 pm

One more consideration.. I'd like to be able to split the mirror at any time and use either disk on it's own in any machine for diagnostic / recovery / testing purposes. Will this be possible with either the ICH6R or Windows software RAID?

PopCorn · Post by **PopCorn** » Sun Dec 16, 2007 9:04 pm

well if u do them in a raid 1 and take the drive out u can put it in any system because raid1 has no "code" or any thing like raid 0 and raid5 does, its simply a mirror of the other hard drive so to answer your question, yes if with raid1 no matter what you use to raid it at any time you should be able to pull either one of the hard drives out and stick it in another machine and boot off it and u will have all the same apps and settings, one thing about raid 1 u probably know, say you put (2) 200gig hard drives in a raid1, you don't get 400gbs of storage, you only get 200gb, also during writes to the hdds its alittle slower (not by much) because it has to write to (2) hdds instead of one, but during reads off the hdds in theory it should be faster because can pull what ever its looking for off either of the hard drives if the other is busy doing something els

Nick Geraedts · Post by **Nick Geraedts** » Mon Dec 17, 2007 2:08 pm

Intel chipsets are pretty good when it comes to using the drives independently (i.e. in another system if needed). I'd suggest using the ICH6R chipset controller. Going with a high end controller isn't going to give you any benefit for RAID1. Dedicated hardware RAID controllers only help for high I/O environments or for RAID5/6.

theycallmebruce · Post by **theycallmebruce** » Fri Dec 21, 2007 10:50 pm

Well, in defiance of popular opinion I've opted for the Windows software RAID.

I would have used the ICH6R fakeraid, but I couldn't figure out how to get into the ICH6R RAID configuration screen

The BIOS options on my motherboard are very confusing, as it has six IDE ports and four SATA ports on board, with two of the IDE ports controlled by the ICH6R, four of the IDE ports by a VIA raid controller, and the SATA ports by the ICH6R. I tried a multitude of configuration combinations, but I just couldn't get it set up the way I want, and the manual is next to useless.

Anyway, thanks for your opinions.

VanWaGuy · Post by **VanWaGuy** » Sat Dec 22, 2007 4:15 am

Well, to go completely off the board, I will say none of the above.

It is good that a potential hardware issue got you thinking about this issue, but when you first start being concerned about a drive failing, and potentially losing your data, what you really need to consider is the bigger picture of how to protect (backup) your data, and RAID may or may not be part of the answer.

Raid is not a cure-all for data protection. If your drive hardware suddenly goes out, then yes, you have a nice copy of your data, and it should be very fresh. (Nothing lost since last backup.)

However, if you have some sort of software data corruption, virus, malware, worm, etc, that manages to write to your hard drive before it is detected, then all RAID will accomplish is making sure that you have 2 similarly affected drives.

Nick Geraedts · Post by **Nick Geraedts** » Sat Dec 22, 2007 8:45 am

To get into the Intel Matrix manager BIOS screen you need to enable RAID mode in the BIOS first. Once you do, the computer will boot, and give you the option of loading the IMM confuration (Ctrl+I - I believe). In there, you can set your RAID configuration as you wish.

Just be warned - you'll need to integrate your chipset drivers into your installation CD to be able to install Windows on a RAID array.

bkh · Post by **bkh** » Sat Dec 22, 2007 7:21 pm

I second the "none of the above" comment. I had been using a hardware mirrored pair (2 disks on an adaptec card) for my Windows XP "C drive" and evidently suffered a power glitch that happened during a disk write, trashing both disks simultaneously. Neither disk was bootable after that disaster. Fortunately I was keeping backups too....

Wedge · Post by **Wedge** » Sun Dec 23, 2007 7:05 am

Can someone tell me if ANY form of RAID will increase desktop PC performance? Or if maybe it depends on the application(s), and if so, what are they?

I set up a fake RAID using ICH9R with two 160GB Seagates for my latest C2D build. Not sure if it performs any better than my non-RAID single 250GB Seagate drive in a separate rig with a 2.8GHz Northwood. If I can't at least perceive some difference, it makes me think it's not really worth it. Maybe my expectations of how any RAID should increase performance is bases on a flawed understanding of RAID.

inti · Post by **inti** » Tue Dec 25, 2007 1:31 pm

RAID is very difficult to make silent - whenever I've tried it, 'seek' noises from HDD become very much more obtrusive, because both drives are seeking exactly simultaneously.

Therefore I agree with other posters. Use a single working drive, and implement a sensible backup system using one or more spare hard drives. I keep my drive partitioned, with a small Windows partition that is easy to backup, a 'personal data' partition for documents and photos (again easy to backup), and only easily replaceable stuff like game installs on the large partition.

mr_plow_king · Post by **mr_plow_king** » Tue Dec 25, 2007 5:20 pm

RAID 0 will increase the performance on hard drive intensive applications and, if you install Windows on a RAID 0 array, the boot time will be reduced

However, since it's less " secure " in case of drive problems, I keep my personal and important files on a non-raid drive and I backup them on an external hard drive

Nick Geraedts · Post by **Nick Geraedts** » Wed Dec 26, 2007 7:10 pm

Wedge wrote:Can someone tell me if ANY form of RAID will increase desktop PC performance? Or if maybe it depends on the application(s), and if so, what are they?

RAID0 will give you the best overall drive performance, since it's simple logically, and can in some cases nearly reach the 200% theoretical boost in performance. My system boots to a fully loaded desktop in under 20 seconds (from pressing the power button).

The question at hand is how you're measuring your performance boost? You'll notice it the most when you've got multiple disk I/O operations going on at the same time. Try this simple test - do some large file copy operations, and then open a large program (photoshop, CAD software, etc). Chances are, the single drive will bog down a LOT, while you'll notice the lack of performance less with a RAID0 setup.

inti wrote:RAID is very difficult to make silent - whenever I've tried it, 'seek' noises from HDD become very much more obtrusive, because both drives are seeking exactly simultaneously.

Therefore I agree with other posters. Use a single working drive, and implement a sensible backup system using one or more spare hard drives. I keep my drive partitioned, with a small Windows partition that is easy to backup, a 'personal data' partition for documents and photos (again easy to backup), and only easily replaceable stuff like game installs on the large partition.

The question at hand is whether or not the performance boost is worth the silencing loss. For me, working with large video files, the performance boost is well worth the seek noise. On the other hand, I actually don't mind the seek noise that much, since I know that my computer is actually doing something (it's a little bit of confirmation that my system isn't lagging

).

Partitions are actually bad for performance. You're better off creating a proper folder structure, and backing things up by folder.

Chocolinx · Post by **Chocolinx** » Mon Dec 31, 2007 9:13 pm

I recently went RAID 0 a month ago. It's great for what I do. I do a lot of video recording/editing. So lots of files get moved around from externals and stuff. My RAID 0 is actually 2 Notebook Harddrives WD 160s. I noticed a HUGE speed increase after they went RAID. Files move along my drives a lot faster now, and when recording 60FPS it's a lot smoother and less likely to skip frames. That's basically my 2 cents on raid. Great benifits, double the risk. But then again, backup everything as usual and you'll be fine. Most of the time you'll notice when they're dying anyway.

Greg F. · Post by **Greg F.** » Tue Jan 01, 2008 7:44 am

someone on this forum suggested I use Cobian backup. I did and have been happy since. As VanWa guy told us, a software corruption on a RAID1 disk just mirrors it to the second. Cobian and eSata (now) for me. Also some USB flash memory and uploads to Picasa. I also use the Google docs for spread sheet and word processing now. Bookmarks and Foxfire setup saved with Online bookmark Manage and others.
Of course if I know some of you like I think I know you, from reading these posts, then you have everything backed up to multiple computers, not just hard drives.

Sizzle · Post by **Sizzle** » Tue Jan 01, 2008 8:52 am

I've used ICH6R up to ICH9R now. Also used NVRAID as well. All worked well for me.

sailorman · Post by **sailorman** » Sun Jan 13, 2008 3:25 am

Nick Geraedts wrote:To get into the Intel Matrix manager BIOS screen you need to enable RAID mode in the BIOS first. Once you do, the computer will boot, and give you the option of loading the IMM confuration (Ctrl+I - I believe). In there, you can set your RAID configuration as you wish.

hi all, this is correct but....

i'm facing a big problem with a similar procedure with my system...

recently i bought 4 WD7500AAYS (raid edition, 5 years warranty) in order to build my RAID 5 array.

My motherboard is ASUS P5E3 deluxe/wifi@n with INTEL ICH9R raid controller, CPU E6850 core2duo and i use Windows Vista 64bits Ultimate edition installed in a separate drive WD5000ABYS.

i did the same procedure as described in that post (assign as [RAID] from mobo's BIOS, ctrl+I to determine the 4 drives(WD7500AAYS) in a RAID array) but..... windows DO NOT see it at all!!

i installed all the fresh updates and drivers, i did a fresh installation of windows from the beginning but NOTHING.... windows still can not recognise the RAID array not even the 4 drives of the array!!

ps the 4 WD7500AAYS drives only recognised by the OS when i assign them as [IDE] from the BIOS.

does anybody know something more about this problem??? a trick or something that i missed here??????

its my first time im facing a problem like this while i used a RAID array before but in Windows XP environment...

pls let me know asap cause it makes me crazy 3 days now...

thx

dhanson865 · Post by **dhanson865** » Sun Jan 13, 2008 10:28 am

Wedge wrote:Can someone tell me if ANY form of RAID will increase desktop PC performance? Or if maybe it depends on the application(s), and if so, what are they?

I set up a fake RAID using ICH9R with two 160GB Seagates for my latest C2D build. Not sure if it performs any better than my non-RAID single 250GB Seagate drive in a separate rig with a 2.8GHz Northwood. If I can't at least perceive some difference, it makes me think it's not really worth it. Maybe my expectations of how any RAID should increase performance is bases on a flawed understanding of RAID.

In most use RAID 0 and a single drive are not noticeably different in terms of speed.

http://www.codinghorror.com/blog/archives/000335.html goes into it from many angles or you could just go with the AnandTech summary:

If you haven't gotten the hint by now, we'll spell it out for you: there is no place and no need for a RAID-0 array on a desktop computer. The real world performance increases are negligible at best and the reduction in reliability, thanks to a halving of the mean time between failure, makes RAID-0 far from worth it on the desktop.

There are some exceptions, especially if you are running a particular application that itself benefits considerably from a striped array, and obviously, our comments do not apply to server-class IO of any sort. But for the vast majority of desktop users and gamers alike, save your money and stay away from RAID-0.

As to performance on RAID 1, RAID 10, and RAID 5

Assuming there are 3 reads for every write, the penalty factor for RAID 5 is 0.57 and for RAID 1 (or 0+1) it is 0.8.

It's also worth looking at http://support.microsoft.com/kb/929491 which discusses why RAID 5 performance may be slower than expected and what to do to avoid the issue.

CAUSE
This issue may occur if the starting location of the partition is not aligned with a stripe unit boundary in the disk partition that is created on the RAID.

A volume cluster may be created over a stripe unit boundary instead of next to the stripe unit boundary. This is because Windows uses a factor of 512 bytes to create volume clusters. This behavior causes a misaligned partition. Two disk groups are accessed when a single volume cluster is updated on a misaligned partition.

AndyB wrote a good post that summarizes some choices on RAID strategies

modified by dhanson865 wrote:Basically when it comes to RAID, there is only a couple of things you need to know.

How much storage your get for using how many drives.
How much redundancy you will get.

Here are a couple of examples for you to get 2TB of storage, with a max drive failure before you actually loose data.

RAID-1+RAID-1, 4x 1TB drives arranged as 2x 1TB drives that are mirrored, you would then see 2x separate drives where you could have 1 failure per array before loosing data, the main benefit here is that you could back-up really important stuff from one array to another, you would in essence have 4 copies.

RAID-10, similar setup with a speed benefit, but a slightly higher risk rate.

RAID-5 4x 1TB drives, you can afford the loss of one drive, all 3TB would be listed as a single drive which makes things easy, one benefit is that you only loose 1TB (25%) to redundancy, the drawback is that you have 4 drives and only 1 needs to fail before you panic, if you were using 5 drives you would run a higher risk because you have more drives that can fail but you only loose 20% to redundancy.

RAID-5 3x 1TB drives, just like the example above, but you loose a higher % of storage to redundancy. 2TB of usable space.

RAID-6 4x 1TB drives, just like the above example of RAID-5 with 4 drives, with one major difference, you would loose 50% to redundancy therefore only having 2TB of space, this gives you the same risk as the RAID-1 example, except that you would only have 1 array (and drive letter ideally) which makes data management easier.

I think that about does it for examples, you can figure out your chances with other capacity's and drive capacity's yourself.

AndyB mentioned 5 disk raid 5. I think one more option should be mentioned

RAID 1 + RAID 5. You can do 2x 1TB drives and 3x 500GB drives for 2TB of usable space and lower cost or 2x 1TB drives and 3x 1TB drives for 3TB of usable space and higher cost. RAID 1 on the first two drives for the OS and any situation where write speed is more important (pagefile, database, etcetera). RAID 5 on the remaining 3 drives for the space and read speed advantage. Doing this gives you 2 redundant drives without having the drawback of hardware controller cost and complexity issues with RAID 6.

If disk performance is truly important you can do other combinations too numerous to list them all but here are a few:

RAID1 + RAID1 (OS on one, pagefile or database on the other)
RAID1 + RAID1 + RAID1 (OS on one, database on the other, page file and random data on the third (multiple partitions on the third array)
RAID1 + RAID1 + RAID5 (OS on one, pagefile or database on the other, random data on the third)

Or you could run a high end exchange server and do lots and lots of RAID10 and RAID1 arrays (never RAID5)

Type Contains
Direct-attached storage (RAID 1) Windows, Exchange system files
Direct-attached storage (RAID 1) Pagefile
SAN RAID 0+1 MTA queues and SMTP queues
SAN RAID 1 Log files for first storage group
SAN RAID 0+1 Databases for first storage group

If your server contains multiple Exchange Server storage groups, Microsoft recommends that you create extra volumes. For each Exchange Server storage group, the Exchange log files should be placed on a SAN-based RAID 1 array, while the Exchange databases should be placed on a SAN-based RAID 0+1 array.

But FWIW, I run all my home PCs on a single drive right now due to noise. I'll probably go to running two non raid drives down the road just to move data and page file off the OS drive.

Who knows when SSDs get cheap enough we might be doing RAID on every PC. Give it a few years and I might think about it...

jwickers · Post by **jwickers** » Mon Jan 14, 2008 6:53 am

I will be getting 4x 500G drives, 3x in RAID 5 and one in external case for backups.

I will see what the performance are, i will be doing software RAID on linux. But anyway it should blow away my old notebook drive

PeterL · Post by **PeterL** » Mon Jan 14, 2008 7:34 am

Hi,

I'm in the same situation and I went for "fake motherboard RAID-1" (in my case nForce 4). Cheap, easy to replace if the motherboard goes up in smoke, very little config hassle.

Peter.

dhanson865 · Post by **dhanson865** » Fri Jan 18, 2008 5:53 am

Code: Select all

RAID Level Comparison for arrays up to 8 drives.
Features                RAID 0  RAID 1   RAID 5   RAID 6   RAID 10
Min Drives                2       2        3        4        4
Data Protection           0       1        1        2        2 (Up to one disk failure in each sub-array)
Read Performance         High    High     High     High     High
Write Performance        High   Medium    Low      Low     Medium
Degraded Read Perf       N/A    Medium    Low      Low      High
Degraded Write Perf      N/A     High     Low      Low      High
Capacity Utilization %   100     50      67-87    50-75     50

It's interesting to note that RAID 1 and RAID 10 are the only RAID types listed here that get faster on writes if a drive fails. You lose redundancy at that point so it isn't something you get to take advantage of for long.

Data protection is rated in number of drives that can fail before you lose all your data.
You may still be able to lose data even if a drive doesn't fail.

Degraded performance assumes only one drive has failed.

Typical Applications:

RAID 0: High end workstations, data logging, real-time rendering, very transitory data
RAID 1: Operating System, Transaction databases
RAID 5: Data Warehousing, Web Serving, archiving
RAID 6: Data Archive, backup to disk, high availability servers with large capacity requirements.
RAID 10: Fast Databases, Application servers

If you took each type and gave a performance score with N/a=0, Low=1, Med=2, High=3 and added the data protection number you would have:

RAID 10: 13 points
RAID 1: 11 points
RAID 6: 8 points
RAID 5: 7 points
RAID 0: 6 points

Of course that is based on the minimum array size, if you recalculate for 8 disks you get:

RAID 10: 15 points (2 arrays)
RAID 1: 14 points (4 arrays)
RAID 6: 10 or 8 points depending on making one or two arrays.
RAID 5: 8 or 7 points again depending on making one or two arrays.
RAID 0: 6 points (4 arrays)

You could argue that the performance benefit of the extra drives in a single RAID 5 or RAID 6 array increases the performance enough to merit giving them the higher score either way.

You could consider the lower number of required drive letters for RAID 5 or RAID 6 a blessing if you have lots of data or a curse if you are concerned about performance.

You could argue that capacity utilization % should be factored in to that score or that performance or reliability should be favored more. Tune the values as you like and do the math.

Just don't expect a point system to make it easy to evaluate between having RAID 1 + RAID 1 + RAID 1 or doing RAID 1 + RAID 5. The only purpose of this post is to make you think...

dhanson865 · Post by **dhanson865** » Fri Jan 18, 2008 7:20 am

The high cost of RAID 5
http://www.networkworld.com/newsletters ... stor1.html
http://www.networkworld.com/newsletters ... stor2.html

http://storageadvisors.adaptec.com/2006 ... -x86-cpus/
[quote]Another point is that RAID-5 is becoming â€œyesterdayâ€™s technologyâ€

Time for RAID

How should I implement my 2 disk RAID1?

Time for RAID

OVER A YEAR AGO

same situation