Adding new larger drive to an existing RAID1 file server

[Private Citizen]

I have a Red Hat 9 File server running Samba, Webmin, SWAT, and not much else. The RAID card is a Promise PX4000. Right now I have two 40 gig Samsungs in RAID 1 config.

My plan: Upgrade the storage capacity to 250gig. Since this is a RAID 1 setup, this will require two 250 gig drives when it is all said and done.

My question: Could I slip one 250 gig in the array, let the card write all the info to that 250 gig drive and then after the initail rebuild completes, then add the second new 250 gig drive.

Is this possible or do I not make any sense at all

 

[spectrum]

I could be way off base here but....
If you put the 250 gig drive into the existing array and rebuild the mirror it will only use 40 gigs of the drive. Then when you put the other 250 gig in and rebuild again you will still only use 40 gigs. Only way I know of for sure would be to back up the data, create a new array with the 250's, then copy the data back over. Someone else may have more insight and an infinetly better way, but you can never go wrong backing up your data
Spec

 

[defakto]

some raid controllers allow you to expand hte raid image size, however i think that's only for adding drives to the arrya for raid 5, maybe raid 1 if you use all the same size to add drives too.