Hardware vs Software Mirroring of RAID arrays?

[bluewhaleCA]

We currently have a 2 TB fileserver we put together a year ago. We're considering moving to dual RAID5 arrays which would be mirrored and have one bid from Apple to supply the equipment already, but a question came to mind regarding the mirroring of the arrays. Apples solution is to have two 5.4TB Xserve arrays mirrored using a dual core G5. I also vaguely recall that Windows servers can do this as well. How would/do such 'software' mirrors compare with a hardware mirror? Perhaps having both RAID 5 arrays connected by fibre to an Adaptec controller?

Just curious.. I don't recall seeing anything in Eweek, Infoworld, NW, or any of the other publications on this topic.

Thanks

Paul

 

[technome]

Don't go with OS raid, hardware is safer and faster.
OS based raid requires about 25% of the CPU use, and ram.
High end hardware raids adapters have co-processors, and handle the I/O, which would fall upon the motherboard if the OS is used. Benchmarks for OS versus hardware raid do not show the motherboard affects of OS based raid.

With Windows you would go with a decent hardware raid adapter, a Pci-x at 133 MHz Pci bus motherboard or PCI-express mobo.

Due to the number of disks required for yours needs, SCSI bus saturation needs to be considered, more than two raid channels are needed, along with the largest capacity disks
(300 gig). You could also go SATA


Aberdeen computer

http://www.aberdeeninc.com/

SCSI Drives

http://www.seagate.com/cda/products/discsales/enterprise/family/0,1086,641,00.html

http://www.maxtor.com/_files/maxtor/en_us/documentation/data_sheets/atlas_10kv_data_sheet.pdf