oaly said:
also, the server that we have is filling up quick. what would be the best solution?
Adding more internal drives would be the best solution. I wouldn't consider using an external drive for anything but backups and unimportant, personal data.
going raid for the server
Don't think of RAID as a way to add storage capacity, because that isn't
really what it is for. It would be simpler to just increase storage capacity by adding additional drives without the fuss of assigning them to RAID arrays etc... Think of RAID as more of a way to achieve increased speed or fault tolerance.
All company or office servers
should have RAID. If your server doesn't, please consider it... And don't consider
RAID 0 (speed and great capacity without fault tolerance), but something like
RAID 5 (speed, good fault tolerance, good capacity) or at least
RAID 1 (OK speed, excellent fault tolerance, poor capacity).
RAID 0 (and variants) would be recommended for any server that needs speed, but doesn't contain any data worth saving. It takes 2 or more disks and stripes them together. So 2 x 500 GB drives look like a single 1000 GB drive to the computer. Read speeds are increased slightly, but if one disk goes down, all of your data is lost and some argue that using 2 or more drives without fault tolerance double your chances of drive failure.
RAID 5 (and variants) would is the ideal choice for most servers. This method takes 3 or more disks and stripes them together. You put in 3 x 500 GB drives and get 1000 GB of storage space. The left over 500 GB is used for parity information (fault tolerance) and is used to rebuild your RAID array if one disk goes down. RAID 5 can tolerate one failed drive without data loss. Read speeds are slightly increased.
RAID 1 (and variants) takes 2 or more drives and mirrors them. You put in 2 x 500 GB, you get 500 GB of usable space. The second drive is continually mirroring the first drive, so it has identical data. This provides fault tolerance (one drive can fail without data loss) but at the cost of space. Read speeds could be increased slightly.
If you don't have a need for RAID, then you absolutely
must keep a reliable software backup of your important data. An external hard drive may be a good way for you to keep a good software backup.
So ideally, assuming your data is important, setting up RAID 5 and a large external drive as a backup would be ideal. Keep in mind that any RAID array requires support from your BIOS or RAID controller. 5 has become more common but is still usually found only on 'prosumer' equipment. RAID 50 is generally only available on business/enterprise level equipment.