Provides a method for kernel services to inform the system that an event has occurred within a workload partition (WPAR) that will deny or subsequently will re-allow a checkpoint of the WPAR.
| Item | Description |
|---|---|
| cmd | An integer command that informs the API what action to take on behalf of the caller. |
| kcid | The WPAR ID where the command operation is to take place. |
| varp | A void pointer to different elements depending
on the cmd parameter.
|
Cmd Types
The cmd parameter is supplied on input to the kwpar_checkpoint_status API and describes the type of action or event notification the caller is expecting. The following cmd types are supported:
| Item | Description |
|---|---|
| WPAR_CHECKPOINT_DENY | The caller is experiencing an event within the WPAR identified by the kcid parameter that would deny a checkpoint operation. The caller must supply a pointer to a user readable character string in the varp parameter. |
| WPAR_CHECKPOINT_ALLOW | The caller is clearing a previous checkpoint denial operation. Deny and allow operations are cumulative and thus each denial operation must be matched with an allow operation before a checkpoint is finally re-allowed. |
| WPAR_CHECKPOINT_TRY | Used by the AIX® 5.1 checkpoint system itself. The caller supplies the varp pointer to an integer containing a “willing to wait” timeout in seconds before a checkpoint denial operation is cleared. |
| WPAR_CHECKPOINT_CLEAR | Used by the AIX 5.1 checkpoint system itself. The caller has completed a checkpoint after a successful WPAR_TRY_CHKPNT operation. |
| WPAR_RESTART_CLEAR | Used by the AIX 5.1 checkpoint system itself. The caller has completed a restart. The WPAR restart state is initially set when the WPAR is recreated on the arrival system. |
The kwpar_checkpoint_status kernel service provides a mechanism for kernel services to inform or query the system about a checkpoint denial event. Kernel extensions that experience a temporary event which prevents a WPAR from being the target of a checkpoint operation, must use this API to deny and then to subsequently re-allow a checkpoint when the event clears. An example denial event might occur if a device open is in an un-serialized interim state that cannot handle a checkpoint operation.
The kwpar_checkpoint_status kernel service can be called from the process environment only.
| Item | Description |
|---|---|
| 0 | Success. |
| non-zero | Failure. |
The kwpar_checkpoint_status service fails if one or more of the following errors occur:
| Item | Description |
|---|---|
| EINVAL | The caller has supplied a not valid cmd or other parameter. |
| ENOENT | No WPAR with the kcid ID is currently active in the system. |
| EBUSY | Either of the following situations can lead
to the EBUSY error.
|
| ETIMEDOUT | The caller is waiting for a timeout period during a WPAR_CHECKPOINT_TRY operation but the timer has expired. |