I software RAIDed my hd's and... - Page 2

Factory RAID?

You know if Sager (or PCTorque) configured the 8887s with RAID 0 'from the factory' this would be quite a coup in the industry. Make Alienware's claims of uberperformance look silly and make it easier for us mortals to have this new level of performance.

Also, I would beseech Clevo, in their great wisdom, to dump the floppy on the upcoming D470 and replace it with the option for another hard disk with factory RAID-0 support!!

Yes, would this be sweet?

I'm still not clear on the SYS/BOOT volume being striped

I do not recall from installing XP, but I don't remember a FORMAT DYNAMIC vs. BASIC disk option when installing XP...

I do know that when you set up MS's software RAID, you need to use disks that are not allocated (thus leaving out the boot/sys volume).

Can someone enlighten me, so I don't have to do a re-install just to check: Can one install XP on a dynamic volume from the get-go? I seem to only remember the options for creating a partition (not a VOLUME) and formatting NTFS/FAT32 Quick/Normal... nothing about setting up striping or extending volumes (or any of the Dynamic Disk stuff).

-myrkat

Shayne,

This RAID stuff if so great. Disk performance if such a bottleneck in laptops.

Your benchmarks show a huge increase in throughput.

Could you give us a subjective feel for how much faster the laptop feels to you? Booting, running 6 apps at once, backups, etc.

I am using a 1 Ghz laptop now, and I can sit around and wait for 10-20 secs for stuff to happen. Drives me nuts. Looking forward to living in the land of Sager performance!

This is going to get interesting. Software Raid on a laptop.
How about partitioning a drive into 3 equal partitions and doing a Raid-5 array? Is it still a RAID 5? Not really. The purpose of RAID 5 is to span your data bits(2x8) and your parity bits(1x8) across multiple drives to achieve redundancy. In the event one drive fails, the parity bit is used to rebuild all information. In the event one drive fails in the one drive in a raid 5 array situation, all is lost and performance was crap.

JimM, in your situation, you will lose performance overall semi based on the above example, please don’t do it. Symantec Ghost is a great way to backup data. We use Corporate edition here to manager our networks in conjunction with Sysprep 1.1 to clear the pnpid's, generate a new sid, and to auto attach to our domain with all the latest greatest stuff(In other words, it is robust!). You MIGHT score well on a benchmark, but you will not like the results. In your situation, you would have (1-60gig)20/40+(2-40gig)40. The objective in a RAID-0 Array is to achieve maximum throughput by splitting your bottlenecked "Sustained Data Transfer Rates" among 2 drives effectively "Doubling” your drive bandwidth. Man, in the real world, software raid doesn’t work out that way. Especially if your PRIMARY drive is a split partition in Software emulated raid array. You now have the C drive trying to access the D drive (your new software array) and your primary drive is now splitting time to perform the functions you request, while the second drive is running around 33%. Not ideal in any situation EXCEPT a benchmark. The benchmark would load in memory, and only test the RAID-0 in a simulated (synthetic) test. The reality of it is when you are transferring files, or working, or playing, your overhead from the OS partition is going to chop the second partition used in the raid, while the second drive is rearing full speed but waiting for the battle between drive 1. Not good.

We also use Low Voltage Differential U160 SCSI drives in a RAID-1 and a RAID-5 Array for the integrity of our data. Our primary server uses a 5 Drive Raid Array consisting of 2 drives in a Raid 1 and 3 drives in a Raid 5. The Raid one is split into 2 partitions c and d. C is for the OS, and D is for the exchange server transaction files, and FTP server, so it will not affect anything in the event anything goes poop in the night. The Raid-5 stores all of our data.

The irony of RAID-0 on a single drive is it is just that..... To configure 1 device on a raid controller (that will let you do it) it must be configured as a RAID-0. So let’s say we ALL have RAID!
Unfortunately, RAID stands for Redundant Array of Independent Disks. NOT Inexpensive disks like so many have read in textbooks, including me in "kolledge".

Adam and I have discussed the benefits of some people being able to use the 8887 with 3 hard drives. Including a hardware raid controller for 2 drives in a raid-0 array or Raid-1 array, but it has amounted to nothing more yet due to high consummation of power, heat, and lack of demand (enough to make it happen).
If anyone has any questions about the RAID, please feel free to shoot away. Write back cache? Whats that?

Troy

If I got a 8888 and it still has the option of 3 hds, would it slow down the performance of the actual hds themselves or no? kind fo a stupid question but I want to know

Dont know how many IDE connectors there are in the 8887 ect

NO striping on Boot/System Volume

Well, being as committed as I should be... er, that I am, I immediately set out to re-format and re-install everything just to see if I could do a software RAID-0 install.

NOPE. CANNOT BE DONE. In fact, XP does not recognize it's own DYNAMIC VOLUMES on the install screen!

Oh well, so now I have a 10GB C: + 10GB C:\Applications (mounted in a folder), and a RAID-0 for 92.2GB D:

Interesting, I've never mounted NTFS / Windows partitions into a folder (like *nix) so in my computer, it only shows C: and D: (10gb / 92gb) - even though there's another 10GB inside C:\Applications.

I must say, the load time for BF1942 is noticably faster, though not too much (maybe it was already fast enough).

-myrkat

No.

If you have 2 "dedicated" drives in a Raid-0 array, the results are better than a single drive. If you split the drive, and want only HALF of the drive to be in a 2 drive raid array, you are wasting time. (I didnt think this was possible, but.... If someone found it IS, then I will trust them)

When "drives" are rated like "ATA100" or "ATA150", they are talking about the "theoretical" data transfer rate of the BUS. Raid-0 Boosts your sustained DTR, but still will not achieve full data saturation of the bus. Me being a "gerd"... well, I would do it to test it and play with it, but I would not recommend anyone USE it in a business atmosphere, unless it's raid-1.

It is pretty standard that there are 4 IDE channels in every laptop(silly southbridge) just some are not used, or not capable of being used due to limitations of laptop size or proprietary architecture. The 8887's are capable of using all 4 channels. So you could have 3 hard drives and one optical drive. Ever seen a sony with 3 hard drives?

I dont think so.

Paul Harvey, "Good Day"

The option of being able to replace the TV tuner card with a third hard drive and adding hardware raid on the motherboard sounds like a grand idea for the next big improvement. I'd definitely upgrade my 8887 if the option was offered!

At the moment, I wouldn't mind getting the third hard drive and trying out the software raid. Troy, does PCTorque offer the drive bracket for the TV tuner area?

Yes we do and the pricing is the same as the 2nd bay HD and bracket.

Thanks for the reply, Adam!

I'll be saving up for another HDD soon

I'm a bit confused .

Obviously, there's no point configuring RAID-0 on a single drive.

But striping across two drives seems like a perfectly workable idea. Isn't this what ShayneOSU did?; and didn't he see a near doubling in throughput?, or was this benchmark too artificial?

How is it that myrkat wasn't able to find a way to use dynamic disks and RAID-0, but ShayneOSU was?

Also, what's the difference between 'software RAID' as implemented by XP through dynamic discs and 'software RAID' that is included as a firmware option on the motherboard (ie, upcoming Canterwood)?

I do understand that a dedicated hardware RAID PCI card completely offloads the CPU from disk duties, but that doesn't seem to be available for laptops.

As long as you backup, I don't think you're rolling the dice too much, are you?; especially considering the benefits.

Can anyone clarify?

More confusion...

So, it sounds like the drives you raid need to be used completely for the raid to get good performance and you cant install the OS and load it onto a dynamic disk (RAID) from the get go. So, can you load the OS on one hard drive and then convert the entirety of 2 hard drives to a dynamic disk spanning both hard disks? Thus the OS would be on the raid partition. From my read of the posts here, it seems like this would offer good performance? Has anyone done this and noticed an appreciable increase in speed when doing regular office applications and web browsing (of multiple apps simultaneously?).

Or do you really need 3 hard drives to have raid that really speeds up the system? One hard drive has the OS image, unraided and the other 2 hard drives are raided?

Thanks for all your assistance.

If RAID were built into the motherboard of the laptop, you could set up the drives with striping in the BIOS, and install Windows on it, and everything would be fine. In this case, you'd only need 2 drives and could play with RAID. The RAID information would be stored on the motherboard, so you could erase the hard drives and you'd still have your RAID setup.

But since there's no onboard RAID in our laptops, you have to use software RAID. And of course, with software, that means installing it to the hard drive. What this means is, you cannot format your hard drives once you set the software RAID, or you will lose the RAID setup information, and there goes your RAIDed drives. So using Windows XP to set up the RAID, you're setting up the drives while in Windows. So you have to install Windows on a hard drive before you can work on the RAID setup, meaning at least one drive has to be plain vanilla, with Windows on it, so it can manage your other hard drives with RAID.

I think it's very interesting that Windows XP will allow you to RAID with just two hard drives. I wouldn't even have tried it myself until I got a third drive

I'm no expert at anything I've just said above - just going from my own experiences

Hope it helped a bit!

RAID Explained (In Detail...)

Go here http://www.anandtech.com/storage/showdoc.html?i=1491 for information on RAID. They do a very good job of explaining the various "flavors" of RAID, and their pitfalls. They also have benchmarks and explain the results very well.

If you are considering going to RAID, definitely read this first! It's a great read!


BTW, the short answer is: You will see a performance boost (esp. with the fast processors in the Sager's). But, I don't know why you would want to do it with only two HDD's. Also, you really need two identical HDD's to get RAID to work properly. That means no partitioning. So, a good setup might be:
10 GB OS drive (5400 RPM, if possible)
60 GB RAID 0 Disk 0 (5400 RPM, of course)
60 GB RAID 0 Disk 1 (5400 RPM, of course)

This would give you a 10 GB Os drive and a 120 GB RAID 0 drive. And a higher risk of data loss - so backup!

But read the article!

Here's another one from the perspective of Canterwood mainboards.

http://www.extremetech.com/article2/...1034037,00.asp

3 drive solution

Alright. So using LeFisch050's solution above...
One 60 GB 6022GAX and two 40GB 4019GAX drives.
Arranged as...
Both 40GB drives in RAID-0
C: 10GB partition on 60GB drive (OS)
D: 10GB partition on RAID-0 (Applications)
E: 70GB partition on RAID-0 (Data-storage)
F: 50GB partition on 60GB drive (for backing up RAID-0).

What type of performance would we see here? Now all I have to do is figure out how to off-load as many Win2k apps onto the RAID as possible?
Also, what would this do to Avg Seek Time?

I think one way to do a raid 0 is to start a new intallation of the os in 10 gig. Then use the rest for raid0.

disk0 40 gig total
10 gig(os and drivers)
30 gig(raid0)


disk1 40 gig total
10 gig (pre-partition and formated)
30 gig(raid0)

c:10 gig os & drivers
d:10 gig
e:60 gig raid0


http://support.microsoft.com/?kbid=303184

Troubleshooting

Do not mix hardware RAID-0 with software RAID-0.

A striped volume cannot hold the system or boot partition of a Windows 2000-based system.

You cannot extend or mirror striped volumes.

There is no fault tolerance on a striped volume. This means that if one of the disks becomes damaged or ceases to function properly, the entire volume is lost.

I think Troy@pctorque addressed this very setup. He said that since the OS will need to access files on the non-raid as well as the raid partition it will have to split it's time between the 2 partitions and not end up with a "real' gain in performance. The benchmark is seen as artificial since the app accessing the raid (SiSoft) is loaded into memory and runs from there.

Troy, correct me if I'm wrong.

I think I know what Troy means.

since C: 10 gig (os and drivers) is in tha same physical location of half of the dynamic disk (raid0) it will defeat the purpose of the raid0. I think that in order to work correctly you need three hard drives like somebody else said.

c: os drive0
d: drive1 and drive2 raid0

Bingo on last 2 gents. Artificial / synthetic benchmarks might look tempting, but in reality, if working from OSdrive accessing DataRaidArray(In physical 60-40 split to logical (20-40)+(40) your performance will be degraded overall and "possibly" imroved (example) in a very small margin of accesing the Array from an external device. But I wouldnt bet on it.... But I still dont know if it is possible! Man, talk about ordering 3 cokes and a french fry for dinner. This is just wrong.