This document describes how to estimate the time for online migrating the system and applications from a source server in your IDC or cloud platform to Tencent Cloud CVM.
The migration time is subject to the data transfer speed during migration. You can estimate it by testing the transfer speed between the source server and destination CVM.
If the destination type of a migration task is CVM instance, the estimated migration time is mainly the actual data transfer time.
For example, if the size of the data on all disks to be migrated on the source server is 50 GB and the outbound bandwidth is 100 Mbps, the estimated total migration time will be 1.14 hours as calculated below:
If the destination type of a migration task is CVM image, the migration time includes the actual data transfer time and image creation time.
For example, if the size of the data on all disks to be migrated on the source server is 50 GB and the outbound bandwidth is 100 Mbps, the estimated total migration time will be 1.23 hours as calculated below:
You can use the iperf3 tool to test the data transfer speed, such as bandwidth and speed of data transfer from client to server.
- When you use online migration in the console, if the migration destination is a CVM image, the relay instance
do_not_delete_csm_instancewith a bandwidth cap of 50 Mbps will be created during migration.
- You can dynamically adjust the inbound bandwidth of the destination or relay instance in the console during migration to control the migration speed.
For example, if you use the online migration feature in the console to migrate a server to a CentOS 7.5 CVM instance, you can test the transfer speed in the following steps:
- If the migration destination is a CVM image, a CentOS 7.5 relay instance will be created during migration. To test its speed, we recommend you choose an available Standard model with a low CPU and memory configuration, which is more like the actual migration scenario.
- The default port of the iperf3 server is TCP 5201. You need to add it to and open it in the inbound traffic configuration in the security group of the CentOS 7.5 instance.
Run the following command to install iperf3 in the destination CentOS 7.5 instance:
yum -y install iperf3
Install iperf3 on the source server. Use the installation command corresponding to the Linux distribution on the source server for installation.
If "Server listening on 5201" is returned, the start succeeded.
4. Run the following command to start iperf3 on the source server as the client:
iperf3 -c [destination instance IP]
The returned test result is as shown below, indicating that the transfer speed between the source server and the test CentOS 7.5 instance is 111 Mbps.