Adding a HDD to a RAID 5

Is this a hardware or a software controlled array?

And the answer varies depending on the hardware, if it is a hardware solution, but generally the asnwer is no.

Is this a hardware or a software controlled array?

And the answer varies depending on the hardware, if it is a hardware solution, but generally the asnwer is no.

My understanding of how the Raid works, you can not add a new drive.

Your best bet is to start a second raid if your controller will handle it.

Otherwise the entire first raid would have to be conpletely rebuilt because of the way it is sized and spread among the different drives.

i'm assuming if it's a scsi drive and a server that you are on a hardware raid controller. what i don't know is if your boot drive is raid 5 or just your data drive or both.
to find out, look in Device manager, write down the complete controller driver names. and any drive model numbers. watch a reboot. if you see a controller load its bios, it's the boot drive controller. write all the stuff down it tells you. press CTL S or whatever it is an peek around in there. don't save anything tho.
you will have to look up your raid controller model number at the mfg website to get full instructions to do as you wish. but first understand what you've got as best you can.
you can look at disk administrator to confirm what you see. correct me bfilm but think hardware raided drive array looks like one drive to windows disk administrator. so maybe you just see boot drive and data drive.
RAID 5 eh? i do believe that's one of 'em you potentially can expand. give tip of hat to former admin or salesguy. and you.
i bet if you trusted your backups you'd have tried it by now...so Sgt says go test your backups. right now.
to answer your question: probably yes. depends on exactly your particulars. so go discover them and write them down then go to website of ms or controller mfg.
meanwhile, for example: for certain adaptec scsi raid controllers:
from www.adaptec.com
How to use the Online Capacity Expansion
feature of Adaptec RAID controllers? How to add another drive to the existing RAID array and thus expand the capacity available?

I?d like to offer one or two solutions to your need which is to increase the RAID 5 C: drive.

1. Use Norton Ghost 9.0, which supports hardware RAID 5, to ghost the RAID 5 HDs to a local or network HD. Replace the 3 HDs with larger ones and then image back.

2. If you can create a second RAID, you may ghost directly from your original RAID to the second and boot from it.

I have not tried these but it logically makes sense to me.

Refer to
http://tinyurl.com/brmak Supported RAID levels
http://tinyurl.com/e4ztp How to manually create a Norton Ghost 9.0 backup image

Depending on your MFG yes you can add a drive to an array. We use Compaq servers and a compaq raid controller which performs a hardware raid config. We recently added 2 146 gig drives to one of our servers and all went without a hitch never even required a reboot. we did it while it was live! the controller added the new drives to the array and performed the expansion from a 400+ to a 650+ gig drive.

Hope that helps. BTW all the drives are 146.8 Gb drives and the array is partitioned with 2 partitions one is the C drive (bootable) and the other is for data/RIS.