DISK_PERFORMANCE structure (winioctl.h)
Provides disk performance information. It is used by the IOCTL_DISK_PERFORMANCE control code.
Syntax
typedef struct _DISK_PERFORMANCE {
LARGE_INTEGER BytesRead;
LARGE_INTEGER BytesWritten;
LARGE_INTEGER ReadTime;
LARGE_INTEGER WriteTime;
LARGE_INTEGER IdleTime;
DWORD ReadCount;
DWORD WriteCount;
DWORD QueueDepth;
DWORD SplitCount;
LARGE_INTEGER QueryTime;
DWORD StorageDeviceNumber;
WCHAR StorageManagerName[8];
} DISK_PERFORMANCE, *PDISK_PERFORMANCE;
Members
BytesRead
The number of bytes read.
BytesWritten
The number of bytes written.
ReadTime
The time it takes to complete a read.
WriteTime
The time it takes to complete a write.
IdleTime
The idle time.
ReadCount
The number of read operations.
WriteCount
The number of write operations.
QueueDepth
The depth of the queue.
SplitCount
The cumulative count of I/Os that are associated I/Os.
An associated I/O is a fragmented I/O, where multiple I/Os to a disk are required to fulfill the original logical I/O request. The most common example of this scenario is a file that is fragmented on a disk. The multiple I/Os are counted as split I/O counts.
QueryTime
The system time stamp when a query for this structure is returned.
Use this member to synchronize between the file system driver and a caller.
StorageDeviceNumber
The unique number for a device that identifies it to the storage manager that is indicated in the StorageManagerName member.
StorageManagerName[8]
The name of the storage manager that controls this device.
Examples of storage managers are "PhysDisk," "FTDISK," and "DMIO".
Requirements
Requirement | Value |
---|---|
Minimum supported client | Windows XP [desktop apps only] |
Minimum supported server | Windows Server 2003 [desktop apps only] |
Header | winioctl.h (include Windows.h) |