Can someone help me understand RAID 0, do you have the full amount of GB?

[Phusius]

I have seen on Alienware systems you can get 1.5 TB 3x 500GB SSD's in RAID 0... so do you have actually 1.5 TB of room? Or does it fill up faster so technically you only have 750gb?

 

[zenlaserman]

When in doubt, there are always search engines.

http://en.wikipedia.org/wiki/Standard_RAID_levels

 

[Frick]

You'd have 1.5 TB.

 

[norbert.x]

Yes, you'd have 1.5 with striping (RAID 0)

 

[Phusius]

No, you'd have 500 with striping (RAID 0) if im not mistaken...

#3 post gave complete opposite answer...


lord can someone please answer me lol

 

[TheoneandonlyMrK]

#3 post gave complete opposite answer...


lord can someone please answer me lol

Ive used raid o for years, you do get the full space 1.5tb

 

[norbert.x]

#3 post gave complete opposite answer...


lord can someone please answer me lol

Sry my bad, have been advising another friend and got my answers mixed up....

But a raid0 with 3 drives isn't something i'd recommend anyways... Not as long as data integrity is of importance

 

[qubit]

#3 post gave complete opposite answer...


lord can someone please answer me lol

The best answer was in post 2 by zenlaserman which gives you everything you wanted to know about raid and more.

However, for a quick answer, here are the most common raid levels:

0 striping, no data redundancy, reliability cut by half, performance improvement. You'll see 500GB

1 redundancy, improves reliability, no performance improvement. You'll see 500GB

JBOD: no redundancy, highly unrecommended, no performance improvement, you'll see all the drive capacities added. In your case 500x3 = 1.5TB

 

[brandonwh64]

Raid 0 = Stripe which will combine all the HDD's space so 1.5tb is what you will see
Raid 1 - Mirror which will copy everything you do on one drive to the other as a backup so only 500GB you will see.

I have two 500GB WD blue drives in raid 0 128kb stripe size for over 2 years and I see 1TB

 

[qubit]

Raid 0 = Stripe which will combine all the HDD's space so 1.5tb is what you will see
Raid 1 - Mirror which will copy everything you do on one drive to the other as a backup so only 500GB you will see.

I have two 500GB WD blue drives in raid 0 128kb stripe size for over 2 years and I see 1TB

If you've got two 500GB drives making a 1TB virtual drive then they're in jbod, not raid 0. I hope you have backups...

Check out that Wikipedia article in post 2 if you don't believe me.

 

[brandonwh64]

If you've got two 500GB drives making a 1TB virtual drive then they're in jbod, not raid 0. I hope you have backups...

I do not store anything I intend to need/cannot get again incase of HDD failure. I use a 1TB WD black drive as storage space set to turn off when PC is idle or drive is not being accessed.

With that being said these drives have been good for over 2 years and it would be said for any HDD that fails that most of the time data can not be recovered.

Also I have it in RAID 0 and can provide screen shots if needed.

A RAID 0 (also known as a stripe set or striped volume) splits data evenly across two or more disks (striped) without parity information for speed. RAID 0 was not one of the original RAID levels and provides no data redundancy. RAID 0 is normally used to increase performance, although it can also be used as a way to create a large logical disk out of two or more physical ones.
A RAID 0 can be created with disks of differing sizes, but the storage space added to the array by each disk is limited to the size of the smallest disk. For example, if a 100 GB disk is striped together with a 350 GB disk, the size of the array will be 200 GB (100 GB x 2).

As from WIKI, 100GB x2 drives = 200GB in raid 0

 

[Frick]

If you've got two 500GB drives making a 1TB virtual drive then they're in jbod, not raid 0. I hope you have backups...

Check out that Wikipedia article in post 2 if you don't believe me.

No, that is raid 0.. Not sure what you're on about here. If it was one 500GB disk and one 250GB disk you get 500GB. Its all there in the article.

 

[brandonwh64]

No, that is raid 0.. Not sure what you're on about here.

Yea exactly what I thought reading his post. I have a AMD quad at work I use for crunching and it has two 80GB drives in raid 0 128K stripe and it combines to 160GB.

 

[lilhasselhoffer]

There are a total of four common RAID configurations. These are:

RAID 0 - Striping
+ Writing speed will increase, because both drives are being utilized at once.
- Data safety is halved. Each new drive creates a new point of failure.

RAID 1 - Mirroring
+ Data safety is doubled. Assuming an instant crash, the data is backed up.
- Halved storage capacity due to redundancy.
- Must have even number of drives.

RAID 10 - Striping and Mirroring
+ Speed boost and redundancy.
- Data storage is halved.
- Must have even number of drives, and a minimum of 4.

RAID 5 - Striping and Parity
+ You only lose one drive worth of storage.
- You have a minimum of 3 drives necessary.



So, let's assume 4 2 TB drives are present in the system. You'd have:
RAID 0: 8 TB - Highest Performance (minimum 2 drives)
RAID 1: 4 TB - Lowest Performance (Minimum 2 drives, must be even drive quantity)
RAID 10: 4 TB - Highest Performance with redundancy (Minimum 4 drives, must be even #)
RAID 5: 6 TB - Lowest cost to redundancy (minimum 3 drives)

Just remember, RAID is a bandage and only helps you if you have an instant failure. Degradation isn't accounted for with any of these RAID level, so that slowly failing drive can still bork your system.

 

[Mindweaver]

I've been running 3x 250 WD RE in "RAID 0" for a full 750Gb drive mostly for my steam games for years. I'd suggest anyone to run 3 drives in RAID 0 for the speed and the space. Just realize that running a RAID 0 array is no different in redundancy than running a single drive.. There is no redundancy, but the speed is much higher than a single drive.

I keep the games I play the most on SSD, and the rest on my 750gb RAID 0 array.

 

[Phusius]

thanks all.

also. /dies lol

 

[qubit]

Yea exactly what I thought reading his post. I have a AMD quad at work I use for crunching and it has two 80GB drives in raid 0 128K stripe and it combines to 160GB.

http://img.techpowerup.org/130311/Capture004221.jpg

Yeah my bad, you're right.

It's been a while and I wrote my post off the top of my head while at work, so I was a bit rushed.

 

[Wrigleyvillain]

Yeah it's a nice way of getting one big volume from multiple smaller drives instead of using the operating system's pooling capabilities (as you also get a nice speed boost too since they work in parallel via striping). However, it also significantly raises the chances of data loss as if one drive dies it's all gone. So a RAID 0 volume with three drives is three times as likely to go tits up as a single drive volume.

But I'm sure you keep good backups, right?

 

[McSteel]

I've been running 3x 250 WD RE in "RAID 0" for a full 750Gb drive mostly for my steam games for years. I'd suggest anyone to run 3 drives in RAID 0 for the speed and the space. Just realize that running a RAID 0 array is no different in redundancy than running a single drive.. There is no redundancy, but the speed is much higher than a single drive.

I keep the games I play the most on SSD, and the rest on my 750gb RAID 0 array.

Actually, it IS different from having a single drive: Chance of failure is approximately tripled with three drives. Why? Because if one drive's expected failure chance is X, and the array fails if any one drive fails, the total failure chance is effectively X (1st drive) + X (2nd drive) + X (3rd drive) = 3X, minus some corrections for statistical insecurities.

There are a total of four common RAID configurations. These are:

RAID 0 - Striping
+ Writing and reading speed and storage capacity will increase proportionally to the number of drives, because both all drives are being utilized at once.
- Data safety is halved approximately multiplied by the number of drives. Each new drive creates a new point of failure.

RAID 1 - Mirroring
+ Data safety is doubled for every new redundancy layer (HDD pair). More accurately, for every mirrored drive, the data loss chance is very nearly halved. Assuming an instant crash, the data is backed up. However, there is no protection against logical errors in the filesystem.
+ Read speed is nearly doubled, though write speed is nearly halved.
- Halved storage capacity due to redundancy.
- Must have even number of drives.

RAID 10 - Striping and Mirroring
+ Speed boost and redundancy. Failure chance is about half the chance of a single drive failure. Speed increase is more pronounced in reads than writes.
- Data storage is halved.
- Must have even number of drives, and a minimum of 4.

RAID 5 - Striping and Parity
+ You only lose one drive worth of storage.
- You have a minimum of 3 drives necessary. Redundancy covers one drive failure only.

There are also levels 01, 3, 4, 6, 50... These are mostly upgraded basic levels or (re)combinations thereof.

So, let's assume 4 2 TB drives are present in the system. You'd have:
RAID 0: 8 TB max - Highest Performance (minimum 2 drives)
RAID 1: 4 TB max - Lowest Performance (Minimum 2 drives, must be even drive quantity)
RAID 10: 4 TB max - Highest Performance with redundancy (Minimum 4 drives, must be even #)
RAID 5: 6 TB max - Lowest cost to redundancy (minimum 3 drives)

Just remember, RAID is a bandage and only helps you if you have an instant failure. Degradation isn't accounted for with any of these RAID level, so that slowly failing drive can still bork your system.

A good, informative post, but I felt it could use some enhancements. My additions are in bold. Another thing worth noting is that RAID is not a backup/reliability solution, it is an availability solution. It's there to prevent your server coming to a screeching halt when a hard drive fails - not to "save" you from backing up your data regularly. Well, except RAID0, which isn't truly a redundancy scheme, it's just a speed boost with a reliability hit tradeoff.