Will start out as static data, backups of SQL databases, PST files, compressed tarballs of smb shares etc ...
Data size currently looking like 100 to 200GB.
Will probably want to progress to integrated agents in MS SQL 2008 (and soon to be 2012), Exchange 2010 and Windows Server 2008 R2 Ent and VMWare ESXi 4.1 in the future.
Not sure how to calculate exact data usage. 100GB for starters but how much will be required if i archive daily and keep 6 months
I presume i'm only keeping deltas but i have no idea how much a file will change day to day.