two identical drives: can I do a partial raid 0?

[RIGorous1]

Hi all I have two identical 200gb drives and I want the benefits of raid without the risk of losing everything in the event one drive fails.

Can I do a partial raid 0? for example can I create a 100gb partition on each drive and raid 0 both of those partitions only, while having the other 100gb as free space for picture/movie/document storage?

Thanks,

Rig

 

[EagleEye]

I don't think that it is possible to do a raid 0+1 on only 2 hds, but I could be mistaken.

 

[RIGorous1]

Originally posted by: EagleEye
I don't think that it is possible to do a raid 0+1 on only 2 hds, but I could be mistaken.

No, I don't want both raid 1 and 0 I just want 0 on half of the partitions on each drive and the other half of the partitions on each drive as spare space...

is that possible?

 

[JEDIYoda]

no its not possible!!
whatever you create in raid zero....say you create a 100 mg partition///then you lose whatever is left on that harddrive is unusable!!

 

[Rubycon]

It depends on the controller and its BIOS.

On the LSi's you can most definitely create a conglomeration of logical drives and combined raid arrays that will make the most seasoned storage professional break down!

 

[imported_Tango]

Originally posted by: RIGorous1
Hi all I have two identical 200gb drives and I want the benefits of raid without the risk of losing everything in the event one drive fails.

Can I do a partial raid 0? for example can I create a 100gb partition on each drive and raid 0 both of those partitions only, while having the other 100gb as free space for picture/movie/document storage?

Thanks,

Rig

Hum...<Isn't this exactly what Matrix RAID does? 2 drives, Raid 1+0?

 

[darkxshade]

Originally posted by: RIGorous1
Hi all I have two identical 200gb drives and I want the benefits of raid without the risk of losing everything in the event one drive fails.

Can I do a partial raid 0? for example can I create a 100gb partition on each drive and raid 0 both of those partitions only, while having the other 100gb as free space for picture/movie/document storage?

Thanks,

Rig

Why not just run both drives in raid 0? It's like saying you have 2x1gb sticks of ram and saying you only want to run half of each stick in dual channel(assuming it would be possible).

 

[Jiggz]

NO! When it's raided it means the entire allocation of each drive is under the RAID configuration regardless if you partitioned it into 2, or 3 or even 4 logical drives. Once one of the drives dies, then the whole RAID dies including all logical drives.

 

[JEDIYoda]

Originally posted by: C6FT7
It depends on the controller and its BIOS.

On the LSi's you can most definitely create a conglomeration of logical drives and combined raid arrays that will make the most seasoned storage professional break down!

Sorry you are mistaken C6FT7-- it does not matter the what controller you use...
a raid0 configuration never ever allows you do partition the harddrive and only use a certain amount as raid0!! Impossible...sorry to be so blunt!!
Jiggz
Platinum Member states---

NO! When it's raided it means the entire allocation of each drive is under the RAID configuration regardless if you partitioned it into 2, or 3 or even 4 logical drives. Once one of the drives dies, then the whole RAID dies including all logical drives.

 

[fire400]

Originally posted by: JEDIYoda
no its not possible!!
whatever you create in raid zero....say you create a 100 mg partition///then you lose whatever is left on that harddrive is unusable!!

owned

 

[Rubycon]

Originally posted by: JEDIYoda

Sorry you are mistaken C6FT7-- it does not matter the what controller you use...
a raid0 configuration never ever allows you do partition the harddrive and only use a certain amount as raid0!! Impossible...sorry to be so blunt!!

Sorry but YOU are incorrect.

This is doable, has been done time in and time out. If a drive dies you will lose data ONLY in the striped part of the logical disk however if the other remaining media is used in a fault tolerant array that data is intact.

This is NOT the entry level type featureset you find on desktop mainboard controllers. They only let you create a single logical drive and you have to use all of the media. Not so with LSi's.

 

[V00D00]

Lets see some links to these products. Don't say it exists and debate about it without showing some proof.

I know you can do that with crappy software raid, but that is pretty much useless. I would like to see a hardware solution that can do that.

 

[JEDIYoda]

Originally posted by: C6FT7

Originally posted by: JEDIYoda

Sorry you are mistaken C6FT7-- it does not matter the what controller you use...
a raid0 configuration never ever allows you do partition the harddrive and only use a certain amount as raid0!! Impossible...sorry to be so blunt!!

Sorry but YOU are incorrect.

This is doable, has been done time in and time out. If a drive dies you will lose data ONLY in the striped part of the logical disk however if the other remaining media is used in a fault tolerant array that data is intact.

This is NOT the entry level type featureset you find on desktop mainboard controllers. They only let you create a single logical drive and you have to use all of the media. Not so with LSi's.

I have been doing raid0 set ups since my first computer....
I am sorry to inform you that you cannot take 2 harddrives and set them up in a raid0 set and then partition those harddrives into a seperate partition that is NOT raid0.....
it is impossible to have your cake and eat it too...

You stated....
Sorry but YOU are incorrect.

This is doable, has been done time in and time out. If a drive dies you will lose data ONLY in the striped part of the logical disk (it doesn`t work that way....you cannot have part of your disk raid0 and the other part non raid....then you go --however if the other remaining media is used in a fault tolerant array that data is intact.
what don`t you understand about raid0??? raid0 is never fault tolerant.....
This is NOT the entry level type featureset you find on desktop mainboard controllers. They only let you create a single logical drive and you have to use all of the media. Not so with LSi's.


But I have an open mind..so post some links.....and lets see where you are coming from..

 

[Some1ne]

I believe it's possible to set up a software RAID in Windows that will work like that. It may be possible to do it in hardware via your integrated RAID controller, but I haven't heard of any integrated consumer-level solution that offers that ind of feature, so I doubt you can do it that way with your hardware.

I don't know what, if any, performance gain doing a software RAID will give you, but here's an article that I think describes the basics:

http://www.techimo.com/articles/index.pl?photo=149

 

[JEDIYoda]

Originally posted by: Some1ne
I believe it's possible to set up a software RAID in Windows that will work like that. It may be possible to do it in hardware via your integrated RAID controller, but I haven't heard of any integrated consumer-level solution that offers that ind of feature, so I doubt you can do it that way with your hardware.

I don't know what, if any, performance gain doing a software RAID will give you, but here's an article that I think describes the basics:

http://www.techimo.com/articles/index.pl?photo=149

We already know its possible to set up your hardrives in anysort of raid array.
I believe that you have never set up a raid configuration.
If you have you would know for a fact that it is possible to only set up a designated amount of space as a raid configuration.
BUT.....say you have 2 - 100 gig harddrives and you set them both up in a raid0 configuration....then you make it so only 100gig of the 200 total gigs is raid0...
You will lose the use of the 100 gig`s that is not set up in a raid0 config.
Thats raid0 101...so to speak....
YES-- being a avid gamer I can tell you ther performance increase in a raid0 configuration is well worth the potential loss of any and all info should the raid0 fail....

An excert from the arrticle--- Be aware that if you decide to undertake this delicate procedure that your data is at risk. If you have one drive go down then you?re your RAID configuration is no longer valid. Remember, striping splits your data among the drives, so if you lose a drive to failure you won?t be able to access the half files left behind on the good drive!
Any person who has been using raid configuration for any length of time knows you backup all your files or you transfer your important stuff to zip drives or to another harddrive!!

 

[Rubycon]

I'll try to keep this simple as possible.

Say you have a pair of 36GB disks on a 320-2E HBA.

When you CTRL+M to get into the controller, you want to create a logical disk. You select both physical drives and select RAID0. You pick the usual parameters and then you type in the size. Well if you you select a size smaller than 72GB you can create a second logical disk. Let's pick a size of 50GB.

We fast initialize the disk and go back to the main menu. Time to create a second logical disk. This time we select RAID1 and this will tell us the max size is 11GB (half of the difference, remember we are mirroring which has 50% overhead).

Initialize and disks are now ready.

You can boot from the XP disk, hit F6 and load drivers. Windows will detect TWO drives as if they were physical drives, one will be 50GB (this will be drive 0 if you told the 320-2E to boot from it, for example) and one will be 11GB. You can put anything you want on either volume, it makes no difference.

This is just one example where you can have different RAID modes across just a single pair of disks. Have more disks? You can add RAID5 into the mix.

The neat thing about the 320-2E is it lets you pick policies that are completely discrete for each logical drive. For example you can use your cache to exclusively write back on a RAID5 volume and use write through on a RAID1 or RAID0 volume. You don't even have to use more than one disk as well - these are treated as RAID0 logicals even though there is no interleaving of data.

This positively cannot be done with mainboard RAID. Does not work that way at all.

 

[Some1ne]

We already know its possible to set up your hardrives in anysort of raid array.
I believe that you have never set up a raid configuration.
If you have you would know for a fact that it is possible to only set up a designated amount of space as a raid configuration.
BUT.....say you have 2 - 100 gig harddrives and you set them both up in a raid0 configuration....then you make it so only 100gig of the 200 total gigs is raid0...
You will lose the use of the 100 gig`s that is not set up in a raid0 config.
Thats raid0 101...so to speak....

Um...I run a RAID-0 array on my desktop, and I've had experience setting up and using with RAID-0, RAID-1, RAID-5, and RAID-0+1 arrays in a database server environment. My point was that *software* RAID, as implemented in Windows XP Pro, works on logical drives as opposed to physical ones like the integrated controller likely requires, and as such it is entirely possible to do a software RAID of two 100 GB partitions on different drives and have the remainder of the space on the drives remain usable and non-RAID'ed (which is what it sounds to me that the OP wants). Yes, it's impossible to RAID-0 two physical volumes, and then partition the RAID'ed space and then have the remainder of the space magically become un-RAID'ed, but this isn't want the OP described wanting to do, and it's not what I suggested could be done using a software RAID.