perfstat_virtualdiskadapter Subroutine
Purpose
Retrieves the Virtual Small Computer System Interface (SCSI) or Serial Attached SCSI (SAS) adapter usage statistics in Virtual I/O Server (VIOS).
Library
Perfstat Library (libperfstat.a)
Syntax
#include <libperfstat.h>
int perfstat_virtualdiskadapter (name, userbuff, sizeof_struct, desired_number)
perfstat_id_t * name;
perfstat_diskadapter_t * userbuff;
size_t sizeof_struct;int desired_number;Description
The perfstat_virtualdiskadapter subroutine retrieves one or more Virtual SCSI/SAS adapter usage statistics.
The same function can also be used to retrieve the number of available sets of Virtual SCSI/SAS adapter (VHOST) statistics.
To get one or more sets of Virtual SCSI usage metrics, set the name parameter to the name of the first Virtual SCSI adapter for which the statistics are to be collected, and set the desired_number parameter. To start from the first Virtual SCSI adapter, set the name parameter to the quotation marks (" ") or FIRST_VHOST. The userbuff parameter must always point to the memory area that is big enough to contain the number of perfstat_diskadapter_t structures that this subroutine is to copy. Upon return, the name parameter is set to either the name of the next network adapter, to the quotation marks (" ") after all of the structures are copied.
To retrieve the number of available sets of Virtual SCSI adapter usage metrics, set the name parameter and the userbuff parameter to the value of null, and the desired_number parameter to the value of zero. The returned value is the number of available vhost adapter. The perfstat_virtualdiskadapter subroutine provides the statistics only in VIOS machine.
Parameters
| Item | Description |
|---|---|
| name | Contains the quotation marks (" "), FIRST_VHOST, or the name indicating the first network adapter volume group for which the statistics is to be retrieved. For example: vhost0, vhost1. |
| userbuff | Points to the memory that is to be filled with one or more perfstat_diskadapter_t structures. |
| sizeof_struct | Specifies the size of the perfstat_diskadapter_t structure. |
| desired_number | Specifies the number of perfstat_diskadapter_t structures to copy to the userbuff parameter. |
Return Values
Upon successful completion, the number of structures filled is returned.
If unsuccessful, a value of -1 is returned.
Error Codes
The perfstat_virtualdiskadapter subroutine is unsuccessful if one of the following is true:
| Item | Description |
|---|---|
| EINVAL | One of the parameters is not valid |
| EFAULT | The memory is not sufficient |
| ENOMEM | The default length of the string is too short. |
| ENOMSG | The dictionary is not accessible. |
Files
The libperfstat.h file defines standard macros, data types, and subroutines.