Re: Mirroring Root Disks

[Martin Bene]

At 22:11 11.02.00 -0800, Andre Hedrick wrote:
>
>You have made an eligant point; regardless, I do not do what you propose
>because ATA ...... the kernel does not yet know how to fake the OS in
>switch to get a boot in a failure.

Depends on how dead the disk is: 
Disk is no longer detected by the bios -> no problem. The software solution
is perfectly capable of booting from the 2nd drive if the first one is gone.

Still recogniced, but can't be read from -> Problem - manual interfention
IS required.

As I concurred before, the hardware raid solution is superior - but then,
there's a lot of room for different solutions and different reliability
requirements - both with regards to financial and technical considerations.

>I will trump the debate with a $2600.00 ATA-Hardware RAID solution I
>showed at [e-mail] 2000.

There's a lot of systems out there where even $2600 is too expensive, and
where a software solution using, say, two $100 ATA drives can still greatly
enhance reliability in omparisn to a system without any mirroring at all.
Also, many systems just plain don't NEED 320GB of storage :-)

>$2600.00 == 320GB (8x40GB ATA Disks) and an 8-channel Host (3ware).
>This was a RAID 0 stripe.
>Imagine that you can remove the disks and shuffle in any order (on the
>same card) and it finds-reconstructs the RAID?

Same goes for the software raid - disks can be moved around any way you want; 

>SCSI can not touch 320GB in disks for $2600.00 USD.

Right on that one, price/performance for ATA Disks is currently really
stunning.

Bye, Martin

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