Greetings,
It really depends on what you are trying to achieve here? ie just add more disks or expand what you already have. At the simplest level if you want to upgrade your 4 18's to 36's, then you must replace ONE drive at a time and allow the RAID to rebuild, then do the next etc until all have been done. At this time the extra space will be visible under the OS. But it will then need to be partitioned etc for the OS. Then create new drives or volumes.
If you are going to add the disk space to existing volumes or drives this may not be adviseable as the volumes with multiple segments etc. A rebuild here is what you really should do to ensure the continuity of the drives/volumes.
Or if you have spare slots in the 3000 they can take up to 10 drives depending on the size. You may want to consider creating a new array with the 36 drives and moving the data or apps. This is relavent as the 36's may be different speed's etc ie if the 18's are 7200 RPM drives and the 36's are 10K drives, you can impact the performance by using mixed spec'd drives in the same array, hence a new array suggestion.
Whatever you choose to do MAKE SURE you have a 100 % tested and reliable backup before you start.
Also make sure the server and RAID card are Flashed to the latest versions as well.
Regards....
