Well, my formula for calculating Exchange replication bandwidth used by Veeam is really pretty simple:pmalinov wrote: I dont understand where the other 18GBs come from
Local Disk (1MB blocks) -- EDB size/2
LAN Target (512KB blocks) -- EDB size/3
WAN Target (256KB blocks) -- EDB size/4
Now, you've provided a little bit of conflicting information on the size of your Exchange as, in your first post you stated that your Exchange server had ~100GB used), while more recently you posted that you had 60 users with 250-500MB mailboxes, which is only ~30GB of EDB max.
If your Exchange is really using 100GB, and your using WAN target, then 20GB is just a little under my "rule of thumb" and that's about the best Veeam is going to do. You can decrease this about 90% with a WAN acceleration box that supports caching, maybe 30-50% if it supports just TCP optimization and advanced compression.