I am trying to decide whether or not to use a RAID array in my new system, or to use a software backup solution to protect my digital files. I have 3 500G SATA hard drives, and I can't decide what the best configuration would be, to acheive a balance of file security (i.e. RAID 1/5 or software backup/disc imaging) and performance, assuming that there might be some improvements in system performance with a RAID solution. I have about 250G of music and images that I need to safeguard, so I thought either a RAID 1 or 5 option might accomplish that, but in the past I have always just backed up my data to another drive, and also kept up-to-date disk images for system repair. My concerns are that trying to get and maintain a RAID array with multiple hard drives could prove challenging and might lead to increased down-time and/or having to troubleshoot issues.

Here are the scenarios that I can see as options. I decided to put this question to a more experienced audience, so I am kindly asking if others could simply point out which scenario seems to make the most sense.

Motherboard: ASUS P5B-Deluxe motherboard, that uses the Intel ICH8R SATA RAID controller
Hard drives: 3 x = 500G SATA II Seagate 7200.10

Possible Choices:

#1. Non-RAID (IDE)
DISK1 as IDE with all software and data
DISK2 and DISK 3 used to store backups of files on DISK1
pros: easy to troubleshoot if system/disks become corrupt, most compatible method where drivers are concerned
cons: not gaining benefits of using AHCI/RAID, backups must be done manually

#2. RAID0
DISK1 and DISK2 striped as RAID0 to offer best performance benefits
DISK3 used to store backups of files on DISK1/2
pros: performance benefits
cons: no data safety, have to replace a drive if RAID breaks, experience system down-time, hard to fix?

#3. RAID1
DISK1 and DISK2 mirrored to provide drive/data copy for safety benefits
pros: data safety through disk mirroring, easier to fix if one drive becomes corrupt as array is not broken
cons: slight decrease in write speeds?

#4. RAID5
DISK1 and DISK2 and DISK3 used in a RAID5 array to provide best mix of performance and safety benefits
pros: performance and safety gains - no down-time if disk is corrupt
cons: possible decrease in performance by using on-board ICH8R SATA RAID controller?

As I am not that RAID-savvy, I have made some assumptions about what the pros and cons might be for each scenario, but they might not even be correct, which is also why I am putting this question out there. I would greatly appreciate any thoughts on what the best option(s) might be, given the motherboard/RAID controller I am using and the desire to preserve data safety, while minimizing any down-time or having to troubleshoot/replace drives if a RAID array becomes corrupt.

My sincerest thanks for any any helpful feedback!

Welcome to MSFN!!!

Funny you should ask... I've got two systems with that exact motherboard, and three different RAID configurations between the two. Your basic assumptions about the various RAID configurations are pretty much correct. Personally, I figure that any data that should be kept should go on RAID1 or higher. Single disks are a way of the past in my books (but others will disagree with me here... ).

On my main system (Quad-core workstation), I've got two WD3200AAKS drives in RAID0. From whatever testing I've been able to do so far (HDTach and copying files with TeraCopy), I can get about 130MB/s read speeds and about 75-80MB/s write speeds.

With my file server, the OS drive is built on two WD2500KS drives in RAID1. Read speeds are around the 65MB/s mark, and writing is at about 40MB/s.

In my file server, I've also got a RAID5 array setup, built with 4xWD5000AAKS drives, but it's connected to a 3ware 9650SE controller. The performance is through the roof (I haven't found an upper limit to the read speed, but I know that write speeds are in excess of 110MB/s), but that's somewhat to be expected from a dedicated controller. This is my storage array, where all backups, music, pictures, and video goes. Anything that wants to be kept is stored here. At the moment, it's about half full.


Is your data in a safe location right now, or is it on one of the three drives that you have? If you've got the three drives to play with, I'd suggest for your sake (and others) to test it out. One good way for you go get around any data that might be on those disks is to "temporarily buy" (buy, use, return) an external USB/eSATA drive from a store like FutureShop or BestBuy (where in Canada are you from, by the way?). Copy all your important data to the external drive, and then put it away. Tinker with your setup until you've found a setup that works for you, and then copy all the data back. That's exactly what I did with my RAID5 array, since I had about 400GB of data at the time.

Personally, I prefer to split up I/O as much as possible. That's why my file server has a RAID1 array for the system drive (OS, software, temp files, etc) and a RAID5 array for static data storage. If you can, I'd try to go along the same route, with with onboard or a dedicated RAID controller if you decide to go RAID5. I know the price is slightly steep, but you might want to consider the 3ware 9650SE-4LPML. If you're worried about performance, you won't have to anymore. I don't know how the RAID5 performance is on the ICH8R chipset, but I'd be curious to find out.

Let us know what you're thinking. Hope this helps!


P.S. Let me be the first to say a very big thank you for having done your homework ahead of time.

I do know. It'll be horrible compared to a controller with a dedicated RAID processor. There are redundancy calculations that have to be done for RAID5 writes. Without a dedicated RAID processor, it'll use the system's CPU. If you're doing anything CPU intensive (playing a game, video editing, etc, etc) then the hard drive write performance will be terrible. This is why I recommended the 3ware controller for your file server.


@kanataguy
There's some pretty in-depth information in this thread. Most of the information there is probably more than you need know...but it's a good read anyway.

For your situation I would recommend using a combination. Set two of the drives up in RAID1 and use the other drive as a stand-alone (and possibly as a backup alternative to the RAID1 set). Also, there shouldn't be any write slow downs with RAID1. A lot of people say this, but there aren't. The "slow down" most people mention is the difference between RAID0 writes and RAID1 writes (RAID1 offers no write speed benefits over a single drive, but with a good controller there's no slow down either).

If you REALLY want the best mix of performance and redundancy, get yourself a fourth 500GB drive and setup RAID10. You can (potentially) lose two drives without losing any data. See the thread I mentioned above for more information on RAID10.

Zxian is right about splitting up I/O as much as possible. Hard drives are the single slowest device in your computer so splitting up write and read I/O across as many drives as you can will help increase performance.

Oh yeah...WELCOME!!

Censor's warning - Memnoch is crazy about RAID10. (and probably rightfully so)

It's definitely worth it if you can afford it. And SATA drives being so cheap these days...it's hard to argue against it.

I have to agree about RAID-10. I think most businesses are now going to either RAID-10 or RAID-6 on new installations. If possible, I would get another drive and either do one RAID-10 or two RAID-1s.

-John

A big THANK-YOU to Zxian, nmX.Memnoch and those who responded, as I found your detailed replies to be most helpful! I was rather impressed to receive such prompt assistance from my first post. Obviously these forums are the place to go for up-to-date information.

getting back to my RAID scenarios ...

I like Zxian's idea about keeping the OS, software, pagefile, temp files, etc. on a separate RAID1 or RAID0. I do have a pair of 320G SATAII Seagates that I could possibly devote to the OS and Program Files RAID. Perhaps the best use for my 3 500G drives is to mirror 2 of them as RAID1, and leave the 3rd 500G for backups. I am worried that without a dedicated RAID controller, I might not benefit from configuring the 3 500G drives as RAID5.

I am still trying to install (integrate using nLite) the proper Intel RAID/AHCI drivers for ICH8R prior to installing a slipstreamed copy of WinXP. There is limited documentation about when you enable the BIOS option to RAID or AHCI, as in BEFORE or AFTER you have those drivers installed. I think I am finally getting somewhere, but that is slightly off-topic.

nmX.Memnoch does seem to favour the RAID10 setup, and why not with such a balance between redundancy and performance. My only issue is that can my on-board ICH8R controller make any of this happen? I am starting to doubt if it's even worthwhile to consider a RAID5 array that uses the motherboard's controller. I think given that fact, I might try to stick to using a RAID0 setup for 2 drives for my OS, Program Files, etc. (I save disk images often) and then consider a RAID1 for 2 of the 500G drives with the 3rd one used for backups.

Does this seem reasonable? Can my P5B-Deluxe on-board RAID controller support these two options (2x320G as RAID0, and 2x500G as RAID1), but more importantly, will there be a noticeable hit on performance with this scenario?

I am able to get clean all of these drives with an external hard drive, so there won't be any issue of having important data on any of these drives during a RAID setup. I would start fresh with empty drives.

I just thought of something... What about disk partitions? Are these irrelevant in a RAID0/RAID1 setup? I typically have my drive divided into several partitions (C:WinXP/Progs, D:Pagefile, E:Games, F:MyDocs, G:Backups, H:Installers, G:Downloads, H:Music, I:Pictures, J:Temp, etc.) Does this have any impact on a RAID array? Will these partitions simply be striped or mirrored when created across the other drive? Can I create a RAID0 or RAID1 using a disk that has already been partitioned, or do I need to start from scratch, and partition the RAID drives once the RAID is built?

Many thanks again for your prompt and detailed replies, and I look forward to hearing your thoughts on my latest questions. Oh and Zxian, I am from Ottawa.

Considering that I've never tried it, I'd follow Memnoch's advice about avoiding RAID5 on the onboard controller. You'd probably be best off using the 320GB drives as you said - for the OS and programs. I'll get to your question about partitions later...

As for the RAID/ACHI drivers, I've got them somewhere on my system here, but I'll have to dig around to find them. I'll post a link for you to download them from and integrate them using nLite (like I did for both of my systems).

The ICH8R does indeed support RAID10. Don't be confused by the higher "number" meaning more computationally intensive. RAID10 is actually not very demanding on resources at all. The reason why RAID5 requires computing power is because parity information is calculated for every bit of data that is written to the drives. With RAID10, the data is simply written to one location or the other, so the calculations involved are near negligible. This site has a great explaination of various RAID levels. I'll admit, their diagram for RAID10 is horrible, but if you look at the one for RAID0+1 and think the other way around, you'll hopefully understand what's going on. If you go with just RAID0, 1, and/or 10 for your system, you shouldn't need to worry about any significant performance decrease from your storage subsystem.

I used to partition all my drives into various parts, but I've moved away from doing that, now that I've got multiple hard drives. I generally just categorize everything into folders and let my defragmentation program deal with the rest. A RAID0 drive must be wiped clean to be created, but I think that it *might* be possible to span a single drive into a RAID1 array. That being said - I'd still think you're better off just wiping and starting from scratch if you can. There's less that can go wrong that way.

You mentioned that you have a separate partition for your pagefile... there's actually been a lot of discussion about this, but generally speaking, if you've only got one disk, put the pagefile on the same partition as the operating system and software. Games should be considered software (since that's what they technically are). Keep everything that is "run" on one partition, and you can keep static data elsewhere. Personally, I think that partitions should go the way of the dinosaurs, since they don't really benefit in any way other than some form of organization (but folders can do that for you as well).

He can get the RAID/AHCI driver as well as the chipset driver from here. Note that I selected "Windows XP", but those drivers are also good for XP x64, Vista and Vista x64. The only exception is the driver floppy for x64 Windows. That can be found here.





I don't like doing partitions either. I find that directories provide plenty of organization for my needs. Too many partitions can actually hurt performance anyway. A single partition can be defrag'ed putting the files on the fastest part of the disk. Partitions split the drive up so the read/write heads will have to travel more if you're writing/reading data on multiple partitions at the same time.



I have to recommend the same. Leave the page file alone...just let Windows handle it. Windows XP does a great job of handling the page file on it's own without mucking around with it.


I can make one, and only one, case for partitions. We used to partition drives at work into 40GB C: drives and D: was whatever was left (depending on drive size). We'd use the D: partition to store the Outlook PST's, My Docs and other data files. The reason we did this was if the OS got fragged for whatever reason we didn't have to worry about backing up too much data...just reinstall the OS, join the machine back to the domain and give it back to the user. We've gotten away from doing that though since XP is pretty stable...not to many worries about an OS install getting fragged. Plus we have a GigE network in the office now so backups don't take that long anymore.



EDIT: Corrected "Leave the partition alone" to "Leave the page file alone"...dunno what I was thinking.

Agreed - in fact, even with multiple physical RAID arrays, I generally mount the first as the "storage volume", D:, and then all other arrays as mount points inside this volume. It's also a preferable setup in Cluster and near-line storage as well, as defragmenting or running chkdsk (heaven forbid) doesn't affect the whole volume, just the mount point, reducing possible downtime. One other drawback to the small partitions people make on C: is that they generally don't leave enough room for a pagefile on that drive that's at least the size of RAM in the machine - if the box ever goes south and you need to analyze it, you CAN'T get a memory dump without a pagefile on C: that's at least 2GB (kernel-only) or RAM+64MB (full dump, preferable).

The moral of the story is to use the disk space you have, and partition only when ABSOLUTELY necessary. Oh, and use RAID10 .

Ok, I think you have made valid points about keeping disk partitions to a minimum. I had read this article that seemed to make sense to me, and the reasons provided also seemed valid (http://icrontic.com/articles/os_setup_guide_2005). I guess for some reason, the idea of having the drive physically divided seemed more secure, and easier to manage when it came time to perform disk images. I think I would at the very least create an OS/Programs/pagefile partition (C:) and then leave the rest to folders for separating.

Now, getting back to the RAID options. RAID10 sounds excellent, however I don't have the budget for a 4th drive at this time. So, I am considering the following:

OS and Programs - 2 x 320G HDD as RAID0

Files and Data - 2 x 500G HDD as RAID1

Backups - 1 500G HDD

Thanks for the driver links nmX.Memnoch. I was able to successfully integrate them into an nLite'd copy of XP, and the key to having Windows boot without the BSOD is to enable the RAID BIOS option BEFORE installing XP with the RAID drivers integrated.

So... tonight I will attach my 2 320G drives, and then all 5 SATA drives will be connected. Once I can wipe the OS drives, I will use them to create a RAID0 array, and then do the same with the 2 500G drives for my RAID1 backups array.

I have a few outstanding questions before starting the create the RAID volumes tonight.

1) Can both a RAID0 and RAID1 array be used without much performance hit using the on-board ICH8R controller?
2) Is it fairly easy to recover/troubleshoot from a drive that becomes corrupt or out of synch? I have no concept of what I am getting into should I experience errors with a RAID volume. I will have all my data backed up on the non-RAID 500G drive, and I will also have OS drive backup images (using Acronis True Image) for easy re-installation. Is the worst thing that could happen is I lose a drive and I'll have to replace it? Can the RAID volumes be "re-built" fairly easily? Can you tell I have no experience with RAID failures?
3) cluberti mentioned something about "mount points" in a RAID volume. Can someone clarify? Does this have anything to do with partitions? From my limited experience, when creating the RAID0 or RAID1 arrays, I will simply choose the 2 disks in the CTL-I boot menu. Is it possible somehow to "mount" folders or drive partitions, rather than using the entire drive? Is there any use for this? As I have a lot of storage (2x320G plus 3x500G), should I be aware of different ways to create or mount these RAID volumes?

Ok, that should do it. Phew ... I will appreciate any advice and recommendations, upon which I can then plan to create the best RAID solution - I am looking forward to getting my feet wet in this new domain!

Given the drives that you already have on hand, that's exactly the way I would set them up. Just keep in mind that if you lose one of the drives in the RAID0 array that you lose all the data. This shouldn't be that much of a problem since the main array is generally used just for the OS and apps. RAID0 will give you the performance you're looking for on your OS/apps drive. The only thing you'll need to worry about really backing up from your OS array is your browser favorites/bookmarks and any saved games (provided you play games).

When you're done you should have a C: drive (the RAID0 array) and a D: drive (the RAID1 array) and nothing else. Don't partition the drives at all. Doing so will definitely hurt performance (as well as being harder to manage IMO).

To be honest with you, my main workstation is configured like this:

C: drive (OS/apps) -- 2 x 250GB RAID0
D: drive (data/downloads) -- 2 x 400GB RAID0

However, I have a file server with a RAID5 array (4x400GB) dedicated to storing my important data so I'm not really concerned with losing anything on my primary machine. Yeah, it would suck, but all of my important stuff is backed up or saved to another computer that has drive redundancy.


Yeah, we all completely skipped over that question...not on purpose, we all just forgot to answer it. As you've already figured out, you have to have the RAID enabled in the BIOS and your arrays configured before you install Windows.


Yes, you can do any mixture of array types that the controller and your drive configurations (size/type of drives) allows. There won't be any performance hit at all with mixing array types. RAID0 will give you both good read and write speeds which RAID1 will give you good read speeds with only a minimal (not noticeable) write speed hit.


As I mentioned above, if you lose a drive in the RAID0 array you'll have to replace that drive, recreate* the array and reinstall. On the RAID1 array all you'd have to do is replace the failed drive, then the controller should automatically intiate a rebuild (if not, you can manually kick off a rebuild using either the controller BIOS or by using the Intel Matrix Storage Manager application in Windows).

*Note the use of the term "recreate". In RAID array speak, the term "rebuild" is used for redundant arrays when you're simply replacing a failed drive. The redundancy is then "rebuilt" on that array. "Recreate" means you have to recreate the array from scratch and replace all of the files manually (because it's not a redundant array).


Mount points are something done within Windows. They can be done with single drives or RAID arrays. Basically, instead of giving the drive a drive letter, you tell Windows to create a mount point on another drive letter. For instance, if I had a 500GB drive that was my D: drive and then I added another 300GB drive to the system but didn't want to have another drive letter, I could tell Windows (in Disk Management) to mount the drive at D:\Downloads. Anything saved to D:\Downloads would actually be saved to the new 300GB drive instead of on the 500GB drive.

For your situation I really don't think it's anything you need to worry about.