disk

Documentation

Index

• func AlignedBlock(BlockSize int) []byte
• func DisableDirectIO(f *os.File) error
• func Fdatasync(f *os.File) error
• func GetOBDInfo(ctx context.Context, drive, fsPath string) (Latency, Throughput, error)
• func IsRootDisk(diskPath string) (bool, error)
• func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error)
• type Info
  • func GetInfo(path string) (info Info, err error)
• type Latency
• type Throughput

Functions

func AlignedBlock

func AlignedBlock(BlockSize int) []byte

AlignedBlock - pass through to directio implementation.

func DisableDirectIO

func DisableDirectIO(f *os.File) error

DisableDirectIO - disables directio mode.

func Fdatasync

func Fdatasync(f *os.File) error

Fdatasync - fdatasync() is similar to fsync(), but does not flush modified metadata unless that metadata is needed in order to allow a subsequent data retrieval to be correctly handled. For example, changes to st_atime or st_mtime (respectively, time of last access and time of last modification; see inode(7)) do not require flushing because they are not necessary for a subsequent data read to be handled correctly. On the other hand, a change to the file size (st_size, as made by say ftruncate(2)), would require a metadata flush.

The aim of fdatasync() is to reduce disk activity for applications that do not require all metadata to be synchronized with the disk.

func GetOBDInfo

func GetOBDInfo(ctx context.Context, drive, fsPath string) (Latency, Throughput, error)

GetOBDInfo about the drive

func IsRootDisk

func IsRootDisk(diskPath string) (bool, error)

IsRootDisk returns if diskPath belongs to root-disk, i.e the disk mounted at "/"

func OpenFileDirectIO

func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error)

OpenFileDirectIO - bypass kernel cache.

Types

type Info

type Info struct {
	Total  uint64
	Free   uint64
	Files  uint64
	Ffree  uint64
	FSType string

	// Usage is calculated per tenant.
	Usage uint64
}

Info stat fs struct is container which holds following values Total - total size of the volume / disk Free - free size of the volume / disk Files - total inodes available Ffree - free inodes available FSType - file system type

func GetInfo

func GetInfo(path string) (info Info, err error)

GetInfo returns total and free bytes available in a directory, e.g. `/`.

type Latency

type Latency struct {
	Avg          float64 `json:"avg_secs,omitempty"`
	Percentile50 float64 `json:"percentile50_secs,omitempty"`
	Percentile90 float64 `json:"percentile90_secs,omitempty"`
	Percentile99 float64 `json:"percentile99_secs,omitempty"`
	Min          float64 `json:"min_secs,omitempty"`
	Max          float64 `json:"max_secs,omitempty"`
}

Latency holds latency information for write operations to the drive

type Throughput

type Throughput struct {
	Avg          float64 `json:"avg_bytes_per_sec,omitempty"`
	Percentile50 float64 `json:"percentile50_bytes_per_sec,omitempty"`
	Percentile90 float64 `json:"percentile90_bytes_per_sec,omitempty"`
	Percentile99 float64 `json:"percentile99_bytes_per_sec,omitempty"`
	Min          float64 `json:"min_bytes_per_sec,omitempty"`
	Max          float64 `json:"max_bytes_per_sec,omitempty"`
}

Throughput holds throughput information for write operations to the drive