Binary Tree and several of our clients have performed multiple laboratory tests to evaluate CMT for Exchange migration throughput. We have observed migration speeds of up to 9 GB of data per hour. However, these numbers have to be qualified with the following factors:
1. Laboratory migrations are performed over a high speed LAN (1000 mbps).
2. Laboratory Domino and Exchange Servers support very few active users.
3. Laboratory Migration workstation(s) normally have 2 GB of RAM or higher (often 4 GB). Although Binary Tree specifies a minimum acceptable amount of RAM as 1 GB, 2 GB is strongly recommended. Also, processor speeds and number of processors increase migration throughput.
4. Higher migration speeds have been observed on physical workstations vs. virtual ones.
5. Migration throughput is higher when migrating smaller number of messages with larger attachments than larger number of messages with smaller attachments.
6. Migration throughput is lower when migrating calendar data, especially repeating calendar events. Large number of reschedules of repeating calendar events dramatically decreases migration throughput.
7. Large number of entries in address translation table used to resolve source recipient lists decreases migration throughput.
8. Large numbers of personal contact distribution lists, and especially distribution lists with many members, dramatically decreases migration throughput.
Note: Laboratory migration performance does not necessarily provide accurate estimates for production migration performance. It is most often used for comparing performance of competing migration products.
Some things to consider that could affect performance:
1. Antivirus - running on-demand scans while data is being migrated can greatly affect performance
2. VM performance - If Exchange servers are running on VMs, it’s important to account for not only CPU and memory performance but I/O capacity as well. If the VMs are sharing the same backplane or fiber connection to a SAN that is at or near capacity this also can greatly affect performance
3. Server maintenance and backups - During the migrations it’s crucial that backups are not running at the same time, nor any Domino maintenance utilities such as compact, updall or fixup.
4. Network - Ensure that there are not saturated links being traversed from the source server, migration workstation and the destination Exchange servers. Also ensure that there is no packet shaping or data prioritization occurring for the migration traffic.