Unusual RAID Question

[JPD]

I'm building a new system for myself. I have two 36GB Raptor HDDS that
I'm considering using in a RAID 0 config. My question is: Must I use
ALL of each drive in the RAID config, or can I use just part of each
drive in RAID and use the rest of the space unRAIDed?

For instance, can I partition the first 5GB of each drive and combine
the two 5GB partitions into a single RAID 0 partition (C for the OS
(XP Pro)?

If I must configure each entire disk as RAID to begin with, then can I
later shrink the RAIDed space into smaller partitions (using something
like Partition Magic) and make nonRAIDED partitions of the remaining
space?

I'm hoping to enjoy the benefits of using RAID 0 for my OS, but
without dedicating the entirety of both drives just to the OS. I've
also got a third drive -- 160GB PATA Barracuda -- that could be used
for data or as an external backup.

Plan B would be to forget about RAID and put the OS and apps on one
drive and data on the other, I guess... but my motherboard (latest MSI
875P FISR) has onboard RAID 0 and I'd like to use whatever benefit
there might be in it.

 

[Toshi1873]

I'm building a new system for myself. I have two 36GB Raptor HDDS that
I'm considering using in a RAID 0 config. My question is: Must I use
ALL of each drive in the RAID config, or can I use just part of each
drive in RAID and use the rest of the space unRAIDed?

Almost all hardware and "hardware (software)" RAID cards
are an all-or-nothing approach. The raid card takes 2+
drives and presents them to the operating system as a
single drive. (The O/S really doesn't even know that
the disks are RAID'd.)

For instance, can I partition the first 5GB of each drive and combine
the two 5GB partitions into a single RAID 0 partition (C for the OS
(XP Pro)?

Sure, if you were to use Linux along with Software RAID.
But you can't in WinXP. In Linux, when using Software
RAID, you can do all sorts of neat stuff like only
mirroring parts of a disk.

If I must configure each entire disk as RAID to begin with, then can I
later shrink the RAIDed space into smaller partitions (using something
like Partition Magic) and make nonRAIDED partitions of the remaining
space?

No, you won't even be able to see the "unused" portion
of the disc.

I'm hoping to enjoy the benefits of using RAID 0 for my OS, but
without dedicating the entirety of both drives just to the OS. I've
also got a third drive -- 160GB PATA Barracuda -- that could be used
for data or as an external backup.

Plan B would be to forget about RAID and put the OS and apps on one
drive and data on the other, I guess... but my motherboard (latest MSI
875P FISR) has onboard RAID 0 and I'd like to use whatever benefit
there might be in it.

RAID0 isn't worth much performance-wise. Better to use
the drives as two separate spindles and put your
temp/swap on the 2nd spindle.

 

[Ron Reaugh]

I'm building a new system for myself. I have two 36GB Raptor HDDS that
I'm considering using in a RAID 0 config. My question is: Must I use
ALL of each drive in the RAID config, or can I use just part of each
drive in RAID and use the rest of the space unRAIDed?

For instance, can I partition the first 5GB of each drive and combine
the two 5GB partitions into a single RAID 0 partition (C for the OS
(XP Pro)?

Depends on what does the RAID.

If I must configure each entire disk as RAID to begin with, then can I
later shrink the RAIDed space into smaller partitions (using something
like Partition Magic) and make nonRAIDED partitions of the remaining
space?

You haven't specified any logical reason NOT to have all of both Raptors in
RAID 0.
You can then use standard Fdisk or PartionMagic to have primary and extended
patitions on the RAID 0 array. The RAID 0 array looks like a single bare
drive to the OS which one can deal with in the same way as an individual
single Raptor.

XP's intrinsic software RAID will probably allow you to use only part of
each drive for a RAID 0 array but that makes little sense often especially
if the OS is on the same drives and on a RAID 0 array.

I'm hoping to enjoy the benefits of using RAID 0 for my OS, but
without dedicating the entirety of both drives just to the OS.

Why NOT dedicate it all to RAID 0 and then divy the RAID 0 into c:, d: etc??

 

[Ron Reaugh]

Almost all hardware and "hardware (software)" RAID cards
are an all-or-nothing approach. The raid card takes 2+
drives and presents them to the operating system as a
single drive. (The O/S really doesn't even know that
the disks are RAID'd.)


Sure, if you were to use Linux along with Software RAID.
But you can't in WinXP.

I beleive you are mistaken.

In Linux, when using Software
RAID, you can do all sorts of neat stuff like only
mirroring parts of a disk.


No, you won't even be able to see the "unused" portion
of the disc.


RAID0 isn't worth much performance-wise.

That's flat false.

Better to use
the drives as two separate spindles and put your
temp/swap on the 2nd spindle.

Just no. That's almost never better performance wise than RAID 0.

 

[Marc de Vries]

I beleive you are mistaken.

He probably means that windows can only use software Raid1 on the
bootdisk and not raid0.

Linux people claim that linux can use software raid0 or raid5 on the
bootdisk.

Marc

 

[Ron Reaugh]

He probably means that windows can only use software Raid1 on the
bootdisk and not raid0.

Linux people claim that linux can use software raid0 or raid5 on the
bootdisk.

So does Linux precognit it's booting and overlay the MBR boot code with code
to parse stripes during the initial partition boot to Linux<g>?

 

[Marc de Vries]

On Mon, 28 Jun 2004 21:08:13 GMT, "Ron Reaugh"

So does Linux precognit it's booting and overlay the MBR boot code with code
to parse stripes during the initial partition boot to Linux<g>?

That's why I said that linux people claim it. I'm not one of them

Maybe they use a bootfloppy? (I remember using a bootfloppy for linux
in a very distant past....)

 

[JPD]

Depends on what does the RAID.

The motherboard (latest MSI 875P FISR) has onboard RAID 0.
http://www.msi.com.tw/program/products/mainboard/mbd/pro_mbd_detail.php?UID=554

You haven't specified any logical reason NOT to have all of both Raptors in
RAID 0.

To enjoy the benefits of RAID 0 for the OS while avoiding the
vulnerability of storing data on RAID 0 disks. If a disk fails,
restoring the OS isn't a big problem.

After all, it's a typical scenario to put the OS on a RAID 0 array and
to put data on a third drive. There's going to be plenty of room on
the Raptors after installing the OS, so why not leave the data
"unRAIDed" on the Raptors, if possible? (Just asking.)