blockdevice

Documentation

Index

• type Diskstats
• type FS
  • func NewDefaultFS() (FS, error)
  • func NewFS(procMountPoint string, sysMountPoint string) (FS, error)
  • func (fs FS) ProcDiskstats() ([]Diskstats, error)
  • func (fs FS) SysBlockDeviceStat(device string) (IOStats, int, error)
  • func (fs FS) SysBlockDevices() ([]string, error)
• type IOStats
• type Info

Types

type Diskstats

type Diskstats struct {
	Info
	IOStats
	// IoStatsCount contains the number of io stats read.  For kernel versions
	// 4.18+, there should be 18 fields read.  For earlier kernel versions this
	// will be 14 because the discard values are not available.
	IoStatsCount int
}

Diskstats combines the device Info and IOStats

type FS

type FS struct {
	// contains filtered or unexported fields
}

FS represents the pseudo-filesystems proc and sys, which provides an interface to kernel data structures.

func NewDefaultFS

func NewDefaultFS() (FS, error)

NewDefaultFS returns a new blockdevice fs using the default mountPoints for proc and sys. It will error if either of these mount points can't be read.

func NewFS

func NewFS(procMountPoint string, sysMountPoint string) (FS, error)

NewFS returns a new blockdevice fs using the given mountPoints for proc and sys. It will error if either of these mount points can't be read.

func (FS) ProcDiskstats

func (fs FS) ProcDiskstats() ([]Diskstats, error)

ProcDiskstats reads the diskstats file and returns an array of Diskstats (one per line/device)

func (FS) SysBlockDeviceStat

func (fs FS) SysBlockDeviceStat(device string) (IOStats, int, error)

SysBlockDeviceStat returns stats for the block device read from /sys/block/<device>/stat. The number of stats read will be 15 if the discard stats are available (kernel 4.18+) and 11 if they are not available.

func (FS) SysBlockDevices

func (fs FS) SysBlockDevices() ([]string, error)

SysBlockDevices lists the device names from /sys/block/<dev>

type IOStats

type IOStats struct {
	// ReadIOs is the number of reads completed successfully.
	ReadIOs uint64
	// ReadMerges is the number of reads merged.  Reads and writes
	// which are adjacent to each other may be merged for efficiency.
	ReadMerges uint64
	// ReadSectors is the total number of sectors read successfully.
	ReadSectors uint64
	// ReadTicks is the total number of milliseconds spent by all reads.
	ReadTicks uint64
	// WriteIOs is the total number of writes completed successfully.
	WriteIOs uint64
	// WriteMerges is the number of reads merged.
	WriteMerges uint64
	// WriteSectors is the total number of sectors written successfully.
	WriteSectors uint64
	// WriteTicks is the total number of milliseconds spent by all writes.
	WriteTicks uint64
	// IOsInProgress is number of I/Os currently in progress.
	IOsInProgress uint64
	// IOsTotalTicks is the number of milliseconds spent doing I/Os.
	// This field increases so long as IosInProgress is nonzero.
	IOsTotalTicks uint64
	// WeightedIOTicks is the weighted number of milliseconds spent doing I/Os.
	// This can also be used to estimate average queue wait time for requests.
	WeightedIOTicks uint64
	// DiscardIOs is the total number of discards completed successfully.
	DiscardIOs uint64
	// DiscardMerges is the number of discards merged.
	DiscardMerges uint64
	// DiscardSectors is the total number of sectors discarded successfully.
	DiscardSectors uint64
	// DiscardTicks is the total number of milliseconds spent by all discards.
	DiscardTicks uint64
}

IOStats models the iostats data described in the kernel documentation https://www.kernel.org/doc/Documentation/iostats.txt, https://www.kernel.org/doc/Documentation/block/stat.txt, and https://www.kernel.org/doc/Documentation/ABI/testing/procfs-diskstats

type Info

type Info struct {
	MajorNumber uint32
	MinorNumber uint32
	DeviceName  string
}

Info contains identifying information for a block device such as a disk drive