New to RAID - Question...

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Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Since I can't decide between RAID 0 or RAID 1, I'm considering 0+1. I'm
trying to find out if there's a way to do striping and mirroring on just
two disks by setting up logical drives.

Is this possible or are 3 disks the minimum? I'd like at least 120GB total
storage. This is all on XP Pro.

I was originally thinking of two 80GB striped, and a 160GB for the mirror,
but was wondering how to do it for a bit less money.

Any recommendations?

Thanks.

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Intel's Matrix RAID lets you do RAID 0 and 1 on different parts of two drives
(just like NT did 10 years ago).

I would forget about RAID 1 on the desktop, just backup to an external drive
instead.

"Bob Huckleby" <bhuck@fastnet.com> wrote in message
news:ZKWdnV2IgLcvQCjcRVn-uQ@comcast.com...
> Since I can't decide between RAID 0 or RAID 1, I'm considering 0+1. I'm
> trying to find out if there's a way to do striping and mirroring on just
> two disks by setting up logical drives.
>
> Is this possible or are 3 disks the minimum? I'd like at least 120GB total
> storage. This is all on XP Pro.
>
> I was originally thinking of two 80GB striped, and a 160GB for the mirror,
> but was wondering how to do it for a bit less money.
>
> Any recommendations?
>
> Thanks.

 

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Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Bob Huckleby <bhuck@fastnet.com> wrote:

>Since I can't decide between RAID 0 or RAID 1, I'm considering 0+1. I'm
>trying to find out if there's a way to do striping and mirroring on just
>two disks by setting up logical drives.

I don't think you've quite grasped the motivation for RAID.

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Bob Huckleby wrote:

> Since I can't decide between RAID 0 or RAID 1, I'm considering 0+1. I'm
> trying to find out if there's a way to do striping and mirroring on just
> two disks by setting up logical drives.
>
> Is this possible or are 3 disks the minimum? I'd like at least 120GB total
> storage. This is all on XP Pro.
>
> I was originally thinking of two 80GB striped, and a 160GB for the mirror,
> but was wondering how to do it for a bit less money.
>
> Any recommendations?

If you want striping and parity you need at least three disks. While it
might be possible to come up with some scheme that provides striping and
parity on two it's not been implemented in any standard or well established
way.

If you want 120 GB RAID 5 will do that for you with three 60 GB disks.
Three 80s would cost less than 2 80s and a 160.

> Thanks.

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Previously Bob Huckleby <bhuck@fastnet.com> wrote:
> Since I can't decide between RAID 0 or RAID 1, I'm considering 0+1. I'm
> trying to find out if there's a way to do striping and mirroring on just
> two disks by setting up logical drives.

> Is this possible or are 3 disks the minimum? I'd like at least 120GB total
> storage. This is all on XP Pro.

> I was originally thinking of two 80GB striped, and a 160GB for the mirror,
> but was wondering how to do it for a bit less money.

Maybe do RAID5 with 3 80GB disks? On reads that is amost as good as
a 2-way RAID-0. On writes it is slower, but so ist RAID 0+1.

Arno
--
For email address: lastname AT tik DOT ee DOT ethz DOT ch
GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
"The more corrupt the state, the more numerous the laws" - Tacitus

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

J. Clarke wrote:

> If you want 120 GB RAID 5 will do that for you with three 60 GB disks.
> Three 80s would cost less than 2 80s and a 160.


Interesting. The first question that comes to mind though is, if I'm
striping with two 80GB drives that gives me 160GB of storage doesn't it?
If that's true, how can that be mirrored on one 80GB drive?

I guess I'll rethink my whole plan as I've just ordered my MSI Neo Platinum
mainboard and I'll be working with the built-in RAID. RAID 5 isn't an
option to me right now.

Sorry for silly questions, but this is all new to me.

Thanks all.

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Bob Huckleby wrote:

> J. Clarke wrote:
>
>> If you want 120 GB RAID 5 will do that for you with three 60 GB disks.
>> Three 80s would cost less than 2 80s and a 160.
>
>
> Interesting. The first question that comes to mind though is, if I'm
> striping with two 80GB drives that gives me 160GB of storage doesn't it?
> If that's true, how can that be mirrored on one 80GB drive?

RAID 5 doesn't involve mirroring, it uses error correction algorithms to
reconstruct the data from any single lost drive in the array using the data
from the remaining drives. All drives in a RAID 5 array are the same size.

> I guess I'll rethink my whole plan as I've just ordered my MSI Neo
> Platinum mainboard and I'll be working with the built-in RAID. RAID 5
> isn't an option to me right now.
>
> Sorry for silly questions, but this is all new to me.
>
> Thanks all.

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

J. Clarke wrote:

> RAID 5 doesn't involve mirroring, it uses error correction algorithms
> to reconstruct the data from any single lost drive in the array using
> the data from the remaining drives. All drives in a RAID 5 array are
> the same size.

I guess it's sort of like a giant PAR file.

Very cool.

Thanks!

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

On Tue, 07 Dec 2004 10:43:30 -0600, Bob Huckleby <bhuck@fastnet.com>
wrote:

>Since I can't decide between RAID 0 or RAID 1, I'm considering 0+1.

The logic of this sentence seems very strange to me.

These are three totally different levels which address totally
different needs. Pick one - don't assume a "hybrid" is right because
it is a "compromise".

> I'm
>trying to find out if there's a way to do striping and mirroring on just
>two disks by setting up logical drives.

it is possible by creating a software raid volume using 2 firmware
raid created logical drives - but it would accomplish nothing or at
least not what it seems you're expecting.

>Is this possible or are 3 disks the minimum?

On some scsi raid. IBM's 1E is similar to 1+0 but starting with 3
disks and including odd numbers of disks. It is also available on the
mylex U160 cards from when IBM owned Mylex. I don't think current LSI
cards do this but you may want to look into it if you are set on it.

> I'd like at least 120GB total
>storage. This is all on XP Pro.
>
>I was originally thinking of two 80GB striped, and a 160GB for the mirror,
>but was wondering how to do it for a bit less money.
>
>Any recommendations?

read more about raid and spend more time thinking what you want to
accomplish as well as how much the raid is worth to you before setting
an arbitrary price point or buying anything.