RAID 5 and Proper Boot Disc/Partition

jethrodesign

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Apr 16, 2004
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Hi, I'm building a new system most likely based on an Asus P5W or P5B (still waiting to see which is better). Both have the Intel chipset that supports a SATA RAID 5 setup.

I would like to get 3 really good SATA drives and build a RAID 5 for my main storage. I'm sick of drives crashing and all of the hassle it brings, especially with ever-increasing storage sizes.

- My question is - would I need to put my operating system boot drive on a seperate drive, or could it be on a 'different partition' on the same RAID array?

I read something about the Intel chipset allowing multiple RAIDs across the same set of discs.

- Is this a similar concept to multiple partitions on a single drive?

- If I'm planning on doing audio recording or video to the main RAID 5 storage area, what would be the performance hit of having the boot drive be on either the same RAID, or a seperate RAID across the same discs?

- If, for performance sake, I make the boot drive a separate drive, can I setup a RAID 1 concept across 2 equal partitions on 1 drive? I don't want to lose the data on my boot drive either, but 5 drives in my machine is just too much (3 for storage, 2 for boot disc)!

THANKS for any help! I'm a bit new to RAIDs and just want to make sure I understand things correctly. I know the usual way to do audio is to have a separate drive for audio from the main boot drive.
 

mkaibear

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>Could it be on a 'different partition'

Yes.

>multiple RAIDs across the same set of discs // similar concept to multiple partitons

Sort of.

Normal RAID works on a disk-by-disk basis - in its simplest form you stick two disks together and mirror the data.

Linux (& Windows) software RAID, and the Intel chipset RAID allows you to, say, take two 80Gb drives, split each one into 2 40Gb partitions, and then RAID 1 two of the partitions for redundancy and RAID 0 two of the partitions for speed.

You end up with;

Disk 1 Partition 1 is in a RAID 0 with Disk 2 Partition 1
Disk 1 Partition 2 is in a RAID 1 with Disk 2 Partition 2

It's a bit more flexible than that, of course, but that's the basic idea.

>planning on audio recording or video

I wouldn't use RAID 5 if I was doing audio recording or video. The write overhead is far too big (because of the Xor calculations).

I would have 2 drives in a RAID 0 for your audio and video work, and 2 drives in a RAID 1 for your O/S and "data storage".

>RAID across 2 partitions on 1 disk.

Yes, you can do this. It's a pretty dumb idea! There's no hardware redundancy - so if the disk fails you still lose everything. (instead of "Redundant Array of Inexpensive Disks" you would have a "Non-redundant non-array of One Inexpensive Disk". So possibly a NOID).
 

jethrodesign

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Thanks for all of the tips!

- So how much perfromance is 'lost' when using a RAID 5 as compared to a single stand-alone drive? Is there a resource where I can find this info easily?

Thanks. I really want to have redundancy and security against losing data. I've heard that a RAID 1 is a real performance stealer compared to a single drive. But I was hoping a RAID 5 may do better.

- Any other ideas for having decent performance for audio/video (at least the same as a standard 7200rpm SATA drive), while at the same time getting the peace of mind of having safe redundancy?

- And what would be the best solution (performance/security) for the boot/OS partition?

THANKS AGAIN FOR ANY HELP! If there are any great resources where I can get the basics on this stuff explained, that may be helpful as well.
 

mkaibear

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>resource where I can find this info easily

It depends on the controller, the disks, and what you're doing with it. Because of the range of factors I seriously doubt you'd find a resource that will tell you definitively.

>RAID 1 is a real performance stealer

RAID 1 doesn't affect the performance of a single drive (at least, not with SATA - having 2 IDE drives on 1 controller in RAID 1 would have an effect). RAID 1 may even make things faster.

>decent performance, peace of mind

RAID 1.

>safe redundancy

An external hard drive and regular backups to recordable DVD.