[svlug] Re: 3ware IDE RAID Recommendation ...

Rick Moen rick at linuxmafia.com
Tue May 30 13:39:57 PDT 2000


begin  Bryan -TheBS- Smith quotation:
 
> *BUT*, 3ware makes some excellent co-processed RAID controllers. 

Sorry, I don't care if they're coprocessed:  Using one IRQ per drive
pair is not OK.  Neither is lack of hot-fix on the drives.  Nor:

> One-channel per drive, a i960 (I believe) on-board to off-load the
> CPU, and FULL SCSI COMMAND-TAG QUEUING (even in the Linux driver)

Sorry, but if you're using ATA disks, by definition you cannot properly
implement SCSI-style command optimisation.  Elevator seeking is not 
possible, for example.  The host adapter lacks the ability to properly
manage pending requests, because of the relatively primative
adapter-to-drive bus.

> -- a major key to performance (whereas the Promise cards are NO
> FASTER than software RAID in NT or Linux).  

> This translates into a very cheap...

Yep.

> ...and efficient...

Efficient of money:  As I said, maximum possible redundant storage per
buck, at the expense of every other design objective.  

> ...higher performance...

I doubt that, extremely. 

> ...low-cost...

Yep.

> ...when you can't afford SCSI RAID.

Save up.

--  
Cheers,     "Not using Microsoft products is like being a non-smoker 40 or 50
Rick Moen    years ago:  You can choose not to smoke, yourself, but it's hard
rick (at) linuxmafia.com     to avoid second-hand smoke."  -- Michael Tiemann





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