span arrays

[NickS]

I have a netfinity 5100, servaraid 4M

Channel 1, 2 drives raid 1
Channel 2 (going to EXP300), 4 drives raid 5

Now I have added 4 new drives to Channel 1, when configuring my Raid I noticed a "Span Array" option in Serveraid Manager.

Will this option allow me to span the newly added drives (4) to the existing Raid 5 on channel two?

If so, will this just added the disk space to my windows volume?

If so, will the existing data on my Raid 5 be ok or will it need to be restored?

Thanks
Nick