The migration function is yet another advantage of using virtual machines in Cloud computing systems. There are two types of migration function: hot and cold.
Hot migration is the transfer of the OS and applications from virtual machines to physical machines without stopping OS operations or applications. In a highly demanding environment such as a public cloud, with even the best servers, the risk of failure starts to rise after around 3 years. Our hot migration function easily avoids downtime caused by failure and maintenance issues with physical machines. Hot migration fulfills several needs:
- Frees up a given physical server for maintenance without downtime for users;
- Dynamically balances workloads among physical servers so that they all run at optimal levels;
- Prevents a facility’s under-performing servers (or those on the brink of failure) from interrupting operations.
Cold migration, meanwhile, suspends OS and applications on virtual machines before transferring them to physical machines. Types of migration available depend on the hypervisor selected. With cold migration, you have the option of moving the associated disks from one datastore to another. The virtual machines are not required to be on shared storage. The virtual machine you want to migrate must be powered off prior to beginning the cold migration process.