Method, apparatus, and computer usable program code for migrating virtual adapters from source physical adapters to destination physical adapters

1. A computer-implemented method in a data processing environment that includes a plurality of host computer systems that are coupled to a plurality of adapters using a fabric for migrating a virtual adapter from a source physical adapter to a destination physical adapter, said computer-implemented method comprising:

causing said virtual adapter to stop processing transactions;

capturing all in-flight transactions that are associated with said virtual adapter;

migrating said virtual adapter to said destination physical adapter by moving configuration information for said virtual adapter from said source physical adapter to said destination physical adapter;

restoring said in-flight transactions; and

restarting said virtual adapter on said destination physical adapter, wherein said virtual adapter is included in said destination physical adapter and wherein said virtual adapter begins processing transactions.

2. The computer-implemented method according to claim 1 , further comprising:

identifying resources on said source physical adapter that had been allocated to said virtual adapter; and

freeing said identified resources after said virtual adapter is moved to said destination physical adapter.

3. The computer-implemented method according to claim 1 , further comprising:

determining an amount of physical adapter resources needed by said virtual adapter;

determining whether said amount of resources are available on said destination physical adapter; and

in response to determining that said amount of resources are available on said destination physical adapter, allocating resources of said destination physical adapter in said amount of resources to said virtual adapter in response migrating said virtual adapter to said destination physical adapter.

4. The computer-implemented method according to claim 3 , further comprising:

said configuration information defining a configuration of said virtual adapter;

in response to determining that said amount of resources are available on said destination physical adapter, reconfiguring said virtual adapter by modifying said configuration information; and

migrating said virtual adapter by storing said modified configuration information in said destination physical adapter.

5. The computer-implemented method according to claim 1 , further comprising:

said configuration information including a pointer to a configuration that defines said virtual adapter.

6. The computer-implemented method according to claim 5 , further comprising:

storing said configuration in a fabric manager.

7. The computer-implemented method according to claim 5 , further comprising:

before migrating said virtual adapter, storing said configuration in a fabric manager and in said source physical adapter; and

after migrating said virtual adapter, storing said configuration in a fabric manager and in said destination physical adapter.

8. The computer-implemented method according to claim 1 , further comprising:

said fabric including a plurality of devices;

each one of said plurality of host computer systems, said plurality of adapters, and said plurality of devices including a queue for storing in-flight transactions;

capturing all said in-flight transactions by moving all in-flight transactions from each one of said queues from each one of said plurality of host computer systems, said plurality of adapters, and said plurality of devices that are either destined to be transmitted to said virtual adapter or that had been transmitted from said virtual adapter.

9. The computer-implemented method according to claim 1 , further comprising:

said fabric being a PCI Express switched fabric that includes a plurality of PCI Express devices.