Background migration of virtual storage

One or more computer storage medias that are not a signal per se having computer-executable instructions that, upon execution by a computer cause the computer to perform operations comprising:

• executing control, by a target host, of a virtual machine executing at a source host before migration of virtual disk data stored in a storage component of the virtual machine;
• migrating the virtual machine and the storage component of the virtual machine from a first storage unit of the source host to a second storage unit of the target host;
• obtaining, by the target host, the virtual disk data via background copying of inbound data at a rate based on an inbound transfer rate threshold;
• throttling the background copying to utilize less than a percentage of a line rate;
• obtaining, by the target host, reads on demand as requested at a higher priority than the background copying of the virtual disk data;
• obtaining, by the target host, newly-written data at a higher priority than the background copying of the virtual disk data;
• servicing, by the target host, read/write requests during the migration of the virtual machine and the storage component of the virtual machine;
• and
• throttling a transfer rate of the inbound data during the migration to stay below a limit specified by the target host.

In a computing environment, a system comprising:

• a memory storing data associated with one or more virtual machines;
• and
• a target host configured to:
• execute control of a virtual machine executing at a source host before migration of virtual disk data stored in a storage component of the virtual machine;
• migrate the virtual machine and the storage component of the virtual machine from a first storage unit of the source host to a second storage unit of the target host;
• and
• service read/write requests during the migration of the virtual machine and the storage component of the virtual machine, including by:
• obtaining the virtual disk data via background copying of inbound data at a rate based on an inbound network data volume threshold;
• throttling the background copying to utilize less than a percentage of a line rate;
• throttling a transfer rate of the inbound data during the migration to stay below limits specified by the target host;
• obtaining on demand reads at a higher priority than the background copying of the virtual disk data;
• and
• obtaining newly-written data at a higher priority than the background copying of the virtual disk data;
• and
• throttling the obtained newly-written data based at least on a rule that at least some of the background copying proceeds while the obtained newly-written data proceeds.