Expanding capacity using larger drives

[hammermedia]

I'm building a NAS using a SATA-II Promise EX16350 controller. I'm building it using four 200GB drives in a RAID 5 config. If over time I replace the 200GB drives with 500GB drives one by one, will the capacity increase once thay have ALL been replaced?

I understand that the space on the 500G drives will be lost until I upgrade the last 200 drive to a 500 but will the array then be 1.5TB or will it stay at 600GB?

As hard drive prices and cost per GB come down I want to take advantage of the newer drives.

My Proliant arrays do in fact increase the capacity but that's on a $3,000 controller and this is to replace tape backup.

Thanks!
Tim

 

[comtec17]

No, I have not seen this work. You will need to migrate all data to the newer RAID set.

Also keep in mind that performance will not change from the 200GB disks to the 500GB disks, they will both have the same I/O speed.

 

[Breslau]

fewer spindles per GB usually means lower performance, although you might not notice it.

 

[hammermedia]

I guess if I had 4 200GB drives totaling 600GB I could create a second array of 3 500GB drives then move over the data and kill the original set.

Do these $600-$900 sata raid controllers allow two RAID arrays in the same cage on the same controller?