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What IS RAID?

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March 29, 2010 9:50:32 PM

I watched youtube but I still not entirely sure what RAID IS?

Or how it works...

More about : raid

a c 127 G Storage
March 29, 2010 10:17:49 PM

In essence RAID is a method of using multiple drives to create one faster and/or more reliable drive. This can be accomplished by either hardware or software (drivers). The different RAID levels differ in the way they store data which affects usable space, performance and reliability. But they all have in common that they use multiple harddrives and create a single virtual 'RAID' drive, that can be used like it was a single disk.
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March 30, 2010 10:16:34 AM

RAID is a method of connecting multiple storage drives together through hardware/software, for one of two outcomes.

RAID 0 basically hooks multiple HDDs up as one large drive, effectivley multiplying the speed by the number of drives connected. being able to seek the data on two separate drives, means half the time waiting for the head to move the the correct point on the platter.

RAID 1 basically stores exactly the same data across the drives in question, meaning that if one is damaged, all the data is still available.

in short, RAID0=performance and RAID1=security.
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March 30, 2010 7:53:00 PM

jakew120 said:
I watched but I still not entirely sure what RAID IS?

Or how it works...


Well before you can get to how it works first you need to know what it is.

In short the point of RAID is redundancy to prevent data loss. This is the fundamental idea of RAID. There are many many forms of RAID. That's a very vague quick summary of it. I feel it's important to get the fundamentals down first before getting into the thick of it.

With the exception of of RAID 0 (striping RAID), All other RAID performs some kind of redundancy. You can ignore RAID 0 as that isn't even used now a days and doesn't even perform redundancy so it'll just confuse things.

Now how it works it depends on the level of RAID. It can get pretty complicated. The most common forms of RAID is RAID 1 (Mirroring) and RAID 5 (Parity) for hard disk drives.

The rest is up to you to read the thick of things. Just remember that the fundamental idea is redundancy to prevent data loss.

you can RAID SANS devices, servers, and even switches (load balancing). The concept still doesn't change - prevent data loss/downtime. Some consider data loss to be downtime.

Good luck!
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March 30, 2010 8:01:40 PM

*blink*

RAID levels include 0, 1,2,3,4,5,6,10,50,100

There are more than 2 levels of RAID.

welshmousepk said:
RAID is a method of connecting multiple storage drives together through hardware/software, for one of two outcomes.

RAID 0 basically hooks multiple HDDs up as one large drive, effectivley multiplying the speed by the number of drives connected. being able to seek the data on two separate drives, means half the time waiting for the head to move the the correct point on the platter.

RAID 1 basically stores exactly the same data across the drives in question, meaning that if one is damaged, all the data is still available.

in short, RAID0=performance and RAID1=security.

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a b G Storage
March 30, 2010 8:12:08 PM

sorry sk8er but there are a lot of people who strip their drives "raid 0" in fact i would venture to say it is the most chosen raid array for performance desktops/workstations, though you are correct it is not a true "raid array" as it is not redundant

and when working with switches it is called link aggregation not raid, raid stands for redundant array of inexpensive disks

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March 30, 2010 8:32:13 PM

ya i know but in the professional world in corporations raid 0 isn't used. If you wanna know what RAID is RAID 0 isn't going to tell you.

No, load balancing of switches is where you have two or more switches balancing the load. It's used quite often so when one switch dies the other can continue operation. you get a neat little email that says "cisco switch down" and it reroutes to a working switch to continue data flow. it's pretty cool.

as for teaming or link aggregation that is something different to what I was talking about.

You can also balance routers and Cisco ASA's.

Again data loss is down time and the concept stays the same if it's RAID or Load Balancing. The Idea is to prevent downtime. Like I said earlier it's important to get the fundamentals down first before diving into what raid 1 is for example.



505090 said:
sorry sk8er but there are a lot of people who strip their drives "raid 0" in fact i would venture to say it is the most chosen raid array for performance desktops/workstations, though you are correct it is not a true "raid array" as it is not redundant

and when working with switches it is called link aggregation not raid, raid stands for redundant array of inexpensive disks

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March 30, 2010 8:42:18 PM

xxsk8er101xx said:
...You can ignore RAID 0 as that isn't even used now a days and doesn't even perform redundancy so it'll just confuse things.


Excuse me, xxsk8er101xx. I am using RAID 0 for performance, and it works quite nicely. I do not care about losing my data - it is backed up to another storage location. The speed is what I desire, and striping gives it to me. I am not alone by any means.

For the new guy, RAID 0 has two or more hard drives in a line. The RAID controller chops the data up into blocks, and each block sent to a different drive. Looking at it simply, two drives means two blocks, almost twice as fast. Three drives, three blocks, almost three times as fast. See where this is going?

Here is a video of a guy that took 24 Samsung Solid State Drives and built a very very fast RAID 0 Array. Why? Just for fun!

http://www.youtube.com/watch?v=26enkCzkJHQ

Are you ready for RAID 1, now? Instead of making separate blocks, the controlloer writes the data two times - that is the redundancy part. So, if one of the hard drives breaks, as they all do eventually, then you still have the other one for an automatic back up. Pretty simple, isn't it?

The other forms of RAID mix and match the splitting and duplicating functions, but it is all pretty much the same theme as RAID 0 and RAID 1.

I know this explanation is simplified, and the other experts may try and argue that I don't have it all perfect, but that is my version of RAID, and I sure hope it helps.
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a b G Storage
March 30, 2010 8:44:19 PM

Quote:
You can ignore RAID 0 as that isn't even used now a days and doesn't even perform redundancy so it'll just confuse things.

False! There are MANY people (me included) who run RAID 0 on OS/scratch disks. (And yes, you don't/shouldn't use RAID 0 on a server; but we aren't talking about servers here).

Quote:
In short the point of RAID is redundancy to prevent data loss. This is the fundamental idea of RAID.

Not exactly. RAID will NOT prevent data loss due to corruption,viruses,etc. The ONLY protection RAID (1,5,etc) provides is against HDD failure.
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a b G Storage
March 30, 2010 8:46:43 PM

xxsk8er101xx said:
ya i know but in the professional world in corporations raid 0 isn't used. If you wanna know what RAID is RAID 0 isn't going to tell you.

No, load balancing of switches is where you have two or more switches balancing the load. It's used quite often so when one switch dies the other can continue operation. you get a neat little email that says "cisco switch down" and it reroutes to a working switch to continue data flow. it's pretty cool.

as for teaming or link aggregation that is something different to what I was talking about.

You can also balance routers and Cisco ASA's.

Again data loss is down time and the concept stays the same if it's RAID or Load Balancing. The Idea is to prevent downtime. Like I said earlier it's important to get the fundamentals down first before diving into what raid 1 is for example.


If the op was in the professional world he would have learned this in school, and raid 0 is still listed as a raid level in every book on my shelf, and used by most regular users of this site

i didn't say "load balancing" I said "link aggregation"
http://www.ieee802.org/3/trunk_study/tutorial/ahtrunk.p...
regardless the term "raid" does not apply to to networking protocols

the idea is to prevent downtime and to increase performance, thus maximizing profit for the capital invested.

and yes you need the fundamentals first but if you give people the incorrect terms now someone else is going to have a harder time explaining it them later when they want the details

writing is writing regardless of the language it is done in, that doesn't make french and spanish the same thing, just because both mediums convey a message using visible symbols
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a c 415 G Storage
March 30, 2010 9:03:44 PM

xxsk8er101xx said:
In short the point of RAID is redundancy to prevent data loss. This is the fundamental idea of RAID. There are many many forms of RAID. That's a very vague quick summary of it. I feel it's important to get the fundamentals down first before getting into the thick of it.


Depending on which RAID organization you choose, you can use RAID to improve one or both of the following hard drive characteristics:

- Performance
- Reliability

It's completely valid for someone to choose performance and ignore reliability, if that's their primary goal. This makes RAID 0 a perfectly valid RAID level. There's nothing wrong with it as long as you're using it for the right purpose and understand it's limitations.

There are plenty of instances even in the corporate world where RAID 0 is used because scratch file performance is important, there's no permanent data at risk, and the occasional down time to replace a failed drive is acceptable.
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a c 415 G Storage
March 30, 2010 9:11:31 PM

xxsk8er101xx said:
Meh please stay away from wiki. There are plenty of professional sites that explains what RAID is.

Wikipedia has it's issues, but it's by far the fastest way to get comprehensive information on virtually anything with a remarkably reliable and consistent format, along with links to supporting material. IMHO it's too valuable a resource to ignore, especially for someone needing technical information.
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March 30, 2010 10:12:52 PM

Wow, has jakew120 even looked at any of these posts? All we seem to be doing here is quoting xxsk8er101xx, and trying (pretty much successfully) to disprove him.

BTW, Sminlal, nice take on Wikipedia. Agree totally with your opionion. I think it really gets a bum rap in the schools these days, likely because it takes too much of the challenge out of research.
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a b G Storage
March 31, 2010 12:21:06 AM

^ Now that you mention it, I use Wiki for school work, except I cite the sources Wiki cites :lol: 
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March 31, 2010 3:24:41 AM

Hmmm. I'm the OP, just for reference. ;) 

Okay, RAID is a collection of hard drives some how (EXPLAIN THIS PLEASE) put together to increase reliability and/or performance using RAID switches (what is this?)

Raid 0 = Speed
Raid 1 = Reliability because it duplicates the info. (Wouldn't this slow it down?)
Raid 5 = Something about parity?

And would setting RAID up for gaming be a good idea.

What I am thinking is the following:

2 HDD RAID 0 as the main hard drive
1 or 2 terabyte HDD as media

Data back up will be through DvDs. (Mostly movies.) And USB (any documents.) I might also get an external hard drive.

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a c 415 G Storage
March 31, 2010 4:12:34 AM

What makes disks into RAID volumes is either hardware, software, or a combination of both. Many motherboards these days include a chipset that works together with Windows drivers to implement RAID. This is what most casual users of RAID use (and that term sends chills up my spin because I think being a "casual user of RAID" is asking for trouble).

Note that no RAID organization can improve access times significantly, and therefore RAID cannot compete with technologies like SSDs to improve the performance of tasks that read a LOT of small files (booting and starting applications are typical examples of this).

You should also understand that RAID 0 increases your chance of data loss because a failure of ANY drive means you loose ALL your data. This means backups are even more important than they would be otherwise.
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March 31, 2010 4:29:49 PM

Does RAID 0 increase the chance of a hard drive failing, or will both hard drives (hopefully) run there normal life span? If it is the latter then I really don't need to worry about RAID 0 as I will back up files like I would on a regular hard drive. If it is the former, then I will reconsider the RAID idea all together.

I also had/have no idea how RAID actually works physically. What do I plug into where, what hard ware do I need etc.? I looked on Newegg under Hard Drives and clicked the section: Controllers / RAID Cards. Do I need one of these cards to run RAID?

If so, I assume I will need drivers, but because I plan to run the OS on the RAID, I don't see how it will work... And do I connect the Hard Drives to the RAID card, or to the motherboard...?
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a c 415 G Storage
March 31, 2010 7:05:12 PM

With RAID 0 each drive isn't any more likely to fail, but if you are using two drives then you have twice as much chance for failure as for a single drive. And, unlike using two independent, non-RAID drives, you loose ALL the data on BOTH drives if EITHER drive fails.

If your motherboard supports RAID then you just plug the drives into the motherboard ports as usual and install the RAID drivers into the OS. Consult your motherboard manual.

If your motherboard doesn't support RAID then you have the choice of using software RAID (i.e., via Disk Manager in Windows) or buying a hardware RAID card, connecting your drives to it, and installing it's drivers.
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April 1, 2010 1:46:36 AM

sminlal said:
With RAID 0 each drive isn't any more likely to fail, but if you are using two drives then you have twice as much chance for failure as for a single drive. And, unlike using two independent, non-RAID drives, you loose ALL the data on BOTH drives if EITHER drive fails.

If your motherboard supports RAID then you just plug the drives into the motherboard ports as usual and install the RAID drivers into the OS. Consult your motherboard manual.

If your motherboard doesn't support RAID then you have the choice of using software RAID (i.e., via Disk Manager in Windows) or buying a hardware RAID card, connecting your drives to it, and installing it's drivers.


I am getting the feeling that you don't want me to try RAID, and I can understand that but I guess I will have to learn the hard way.

So, back to how it works. Let's say that I have everything built in my computer, with 2 HDD that will be RAID 0 and one larger one for media. I plug the computer into the monitor and turn it on.

I go to the BIOS page and set up the RAID according the to motherboard manual. Question: Will I be able to get the first to HDDs in the RAID configuration to be separate from the third? So that the OS will eventually see 2 HDDs?

Then I put windows 7 in the disk tray and boot it up. Questions: Can I add the Drivers from the RAID 0 setup after I get windows set up, or is there a point in the installation where I am allowed to install the drivers? If so, will I need to Disk readers?
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Best solution

a c 415 G Storage
April 1, 2010 2:12:14 AM

The thing is that RAID is a more complex configuration that comes with it's own set of issues, but you're asking very, very basic questions that make me fear you might be getting in over your head. And I really, really hate to give people directions that may cause them grief - it makes me feel a little guilty.

That having been said, it sounds like you're building a brand new system and that means there's nothing much you can blow up - so it's a good place to start.

I can't give you specifics because each RAID implementation is different. You really need to go by the documentation for whichever one it is your using. But I can give you the following general guidelines:

1) Yes, for hardware or motherboard RAID you need to do the BIOS configuration first to set up the RAID volumes, then install the OS.

2) I think pretty much every RAID controller will let you configure two disks as a RAID volume and a third disk as a non-RAID volume. Once you've done that, when you get the system up and running it will look like you have two disks.

3) Windows 7 includes drivers for most of the relatively recent motherboard RAID chipsets such as the Intel ICH series - if you're using one of them then you may not have to do anything special during the installation. Otherwise, when you start the Windows installation you'll need to load the drivers that come with your motherboard or RAID controller card. You do this by choosing "Custom Install" and clicking the "Load Drivers" link in the next window.
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April 1, 2010 2:27:02 AM

I guess you can say that I am getting in over my head. With this new computer adventure I've really dived into the deep end and am sitting at the bottom of a very, very large and deep pool.

Luckily, I am a swimmer and I am slowly working my way to the top. (Top refers to understanding. I don't want to give the impression that I mean the top of the computer world.)

The reason I ask very basic questions is because I like to confirm things, and know the intricacies (relatively of course. I don't mean understanding the electrical layout of the device or whatever.) of what I will be doing.

I am researching many, many topics with this and you have been extremely valuable for this one part. And yes, before I posted this thread, I did both a google search and looked it up in wikipedia but everything I found was far to general.

I appreciate both your assistance and concern but unfortunately for me, I am stubborn.

Again, thanks. I feel relatively comfortable with my knowledge of RAID now. As in, I can set it up. Although I will probably be back asking what HDDs are recommended etc..
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April 3, 2010 5:22:39 PM

So close the thread and choose sminlal as best answer!
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April 3, 2010 9:22:13 PM

Best answer selected by jakew120.
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a b G Storage
April 4, 2010 12:36:20 PM

I'd love to point you to the forum sticky, but it's about 8 years old :lol: 
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