Anyone explain RAID?

Re: Performance

Me! And a lot of others too, I'll bet.

I already have a plan to make a RAID 0 Stripe from 4 x 250GB SATA HDD to make 1 TB disk space volume. No more piles of CDs everywhere - just keep everything on the one data server.

That could go into my current Pentium 4 machine, but I think its more likely I'll push it back until I build the kick-*** next gen machine I am building next year or the year after for longhorn.

1 TB is pretty cool, as you write, no more piles of CD's (DVD's in my case), no more moving around of files so you can make space for the latest games requirements etc but I think you are forgetting one very important detail about RAID 0, which is:

No fault tolerance
if 1 of your 250 GB SATA HDD decides to go to ETHER space (DIE) then it will result in loss of ALL DATA (1 TB!!!).

I hope you have a good backup strategy in case this should occur.

Good luck with your kick *** machine!

OH no, I had not forgotten.

Actually, I am investigating the possbility of a RAID 5 SATA controller. These are not cheap, especially if they support hot swapping HDD drives. But its possible.

Lets see 1 tb raid 0, backup would be a huge pile of cd's.


















j/k I couldn't resist

Out of curiosity, is RAID 5 100% fault tolerant? (with parity drive failure aside ..)

I am not sure I understand how it works totally, but I cannot see how it would be very reliable to rebuild your data with just parity information.

I'm assuming something like RAID 1 or 10 would be more secure, correct?

Well, so long as you never loose more than one HDD at a time, all you have to do is replace that HDD with another one and the data will be regenerated.

This is a lot cooler than RAID 0, but that's why RAID 5 controller cards are a lot more expensive.

Today I just bought 2 x 160GB Maxtor SATA HDD which I am going to RAID 0 into one array.

Go have a look here:

http://www.pcguide.com/ref/hdd/perf/raid/levels/

Adrian

Well, I have dumped my RAID 0 setup for a more traditional master slave setup. I didn't notice any speed benefit and didn't need one 160 gig drive. Now I can use true image to backup my main drive to my slave. Now I can go a clean install from my image in about 10 mins, instead of 10 hours.

Ok so, before I even start to read all of these "Raid" post, I just need to understand the very basics of Raiding, as in how it 100% works and what not. Does anyone know any good sites that explain the basics of it? I've googled a bit, but that's what brought me here, and to a few other sites that jump a little further ahead than my likings. Thanks.

I think I kind of agree with Jared could you guys and gals, explain it kind of like this "Raid for Dummies". I have heard about the benefits of this that and the other, the question is if someone is new to the concept is there a website or someone here that could really explain it in it's simplest form. Which type of Raid, Raid 0, 0/1, 1

Processor: AMD Athlon 64 3400+ Socket 939 CPU (CP2-A64-34009 C )

Motherboard: Asus A8V Deluxe Via K8T800 Pro Socket 939 Motherbo (A455-2110 )

Hard DrivesX2: WD Caviar 120GB Serial ATA HD 7200/8MB/S-ATA-150 (TSD-120JD TSR )

Hard drives are identical

Remaining Hardware is listed in my profile.

Real-world IDE Raid explored
What is RAID

That was exactly what I was looking for I have an external hard drive which I use to store important information and anything that is super important I stick on a DVD anyway. Raid 0 sounds like what I am looking for. Next question. Is the system that I bought going to work, unfortunetly I have not even seen it yet and will not for another couple of months. I just want to make sure that I have everything that I need to make it work when it shows up.

Video card: Radeon 9600 128m

Motherboard and Processor: Asus A8V Deluxe Via Socket 939 ATX Motherboard and AMD Athlon 64 3400+ Processor
(built in 5.1 dobey digit sound)

Memory: Ultra 512MB PC3200 DDR 400MHz Memory
2 sticks

Hard Drives: Western Digital / Caviar SE / 120GB / 7200 / 8MB / SATA-150 / Hard Drive
2 identical ones

Case: EZ-Media G7 Black ATX Mid-Tower Case with Clear Side, Front USB Ports, Front Thermo LCD and 480-Watt Power Supply

Other drives:

Sony DRU710A / 16x4x16x DVD+RW / 8x4x16x DVD-RW / 2.4x DVD+R DL / 48x24x40x CD-RW / Dual / Nero Software / DVD Burner

YE Data USB 2.0 All-In-One Internal Floppy Drive

I am guessing that the ASUS manual is going to explain how to set up the board to set up the RAID...

It looks like that board has a Promise controller on it. They are a staple of the IDE raid market. It shouldn't be too difficult to find information about it.

For me the important thing to consider when getting a raid controller is performance. The cheaper ones are typically software driven. The difference between software raid and hardware is phenominal. Hardware raid controllers, while expensive, have huge perfomance boosts in that they have their own ram and bios. Of course, bus speeds may become the bottleneck.

Another important factor is the drive types. Some software controllers, albeit rare, will let you make a raid from most any drive device. This is dangerous because you will not have a very stable configuration if you use, for instance, an EIDE drive with a SATA drive. Likewise, if the drives have different drive speeds your config will s'plode during a read/write operation. Mixing 5400rpm, 7200rpm, and 10000rpm drives in your raid is not a healthy idea. Some controllers may have compensations for this, but I wouldn't trust them.

Drive size is not that important. Sure if you want to be efficient you should use the same sized drives, but most controllers will normally operate as if all the drives are the size of the smallest drive in your array.

Sorry if this information is redundant.....guh...stupid pun. I was lazy and didn't read the entire thread.

Promise RAID stuff is great.

PATA to SATA

I'm not too sure on RAID and has PATA & SATA got anything to do with making drives into RAID, help! My drives are setup as PATA in BIOS and are speedy @ 7,200 IDE, UDMA Ultra 5 mode (whatever that means).

I'm guessing the 'S' is Serial and 'P' is Parallel. Is PATA for 40pin cables & SATA for the smaller/narrower 80pin cable. Is that right?

So if I changed it to SATA would I then have RAID & how much faster is it than my current speeds? My Half-Life 2 loading level screens takes 90+ seconds to load with a AMD Athlon 3400+ 512L2 cache.

I'd appreciate any help :giddy:

NO. The controller determines used determines whether RAID is supported or not. There is STA Raid and PATA Raid.

NO, 40 wire 40 pin and 80 wire 40 pin cables are both parallel IDE cables. The 80 wire 40 pin cable is required for (I believe) ATA 66 and above speeds.

First off, to use RAID you have to have a controller that supports it. SATA drives are faster than IDE. SATA drives are ATA 150, IDE drives are ATA 133 and below. I believe Ultra DMA 5 mode is ATA 100. Raid can be faster or slower depending on what mode you use, striping or mirroring. For two drives RAID 0 (striping) gives you an increase in read speed. Technically it's not really Raid because you don't have any redundant drives, lose one lose them all.

I have a raid array 0

I will put it to compete against any single drive reading and writing and it will out do anything as long as its not SCSI. It read slower cuz they didnt have the ram or cpu appropiate for it. remember the machine is as fast as its slowest piece

Thanks for the advice Alphunumeric. When I bought my PC it says that Ultra DMA mode 5 is 133Mbps for IDE. So it must be right but unless someone has a list for the 'DMA modes' then it's anyone's guess!

The motherboard I have that I want to put two SATA drives on with my two IDE drives is a MS 6741. I've tried finding out about which SATA drives to use and if I can use them with two IDE drives, so if some buffs could give me a hand - don't clap

I'm using Windows XP Pro SP2.

Compaq Proline 1500 server; P1 166Mhz + P1 166Mhz co.

I've got a Compaq Proline 1500 server with a capacity of 5 disks of which 4 are taken by 1 9Gb and 3 18.9Gb disks.
It used to run under Win2k server for the last time, which was installed on the 9Gb.
I managed to save it from going to the junkyard when the company I worked for closed down.
I'm planning to make this baby running on linux to start learning and working with server technology.
Any info I can get somewhere in how to install from scratch and how to configuring it's raid?

Greetz,
ßeetlejuice

My mistake, mode 5 is ata-100 and mode 6 is ata-133,
Ultra DMA
Mode, Maximum Transfer Rate (MB/s)
Mode 0, 16.7
Mode 1, 25.0
Mode 2, 33.3
Mode 3, 44.4
Mode 4, 66.7
Mode 5,100.0
Mode 6,133.0

You should be able to set up a Sata raid array and a separate IDE drive Raid array. I don't believe you can mix and match sata and IDE in the same raid array, if that is what you are wondering.