[linux-2.6-block.git] / Documentation / ABI / testing / procfs-diskstats

What:		/proc/diskstats
Date:		February 2008
Contact:	Jerome Marchand <jmarchan@redhat.com>
Description:
		The /proc/diskstats file displays the I/O statistics
		of block devices. Each line contains the following 14
		fields:

		==  ===================================
		 1  major number
		 2  minor number
		 3  device name
		 4  reads completed successfully
		 5  reads merged
		 6  sectors read
		 7  time spent reading (ms)
		 8  writes completed
		 9  writes merged
		10  sectors written
		11  time spent writing (ms)
		12  I/Os currently in progress
		13  time spent doing I/Os (ms)
		14  weighted time spent doing I/Os (ms)
		==  ===================================

		Kernel 4.18+ appends four more fields for discard
		tracking putting the total at 18:

		==  ===================================
		15  discards completed successfully
		16  discards merged
		17  sectors discarded
		18  time spent discarding
		==  ===================================

		Kernel 5.5+ appends two more fields for flush requests:

		==  =====================================
		19  flush requests completed successfully
		20  time spent flushing
		==  =====================================

		For more details refer to Documentation/admin-guide/iostats.rst
Commit	Line	Data
0e53c2be JM	1	What: /proc/diskstats
	2	Date: February 2008
	3	Contact: Jerome Marchand <jmarchan@redhat.com>
	4	Description:
	5	The /proc/diskstats file displays the I/O statistics
	6	of block devices. Each line contains the following 14
	7	fields:
bdca3c87	8
34433332 MCC	9	== ===================================
34433332 MCC	10	1 major number
ebab9426	11	2 minor number
34433332 MCC	12	3 device name
	13	4 reads completed successfully
	14	5 reads merged
	15	6 sectors read
	16	7 time spent reading (ms)
	17	8 writes completed
	18	9 writes merged
	19	10 sectors written
	20	11 time spent writing (ms)
	21	12 I/Os currently in progress
	22	13 time spent doing I/Os (ms)
	23	14 weighted time spent doing I/Os (ms)
	24	== ===================================
bdca3c87 MC	25
	26	Kernel 4.18+ appends four more fields for discard
	27	tracking putting the total at 18:
	28
34433332 MCC	29	== ===================================
	30	15 discards completed successfully
	31	16 discards merged
	32	17 sectors discarded
	33	18 time spent discarding
	34	== ===================================
bdca3c87	35
b6866318 KK	36	Kernel 5.5+ appends two more fields for flush requests:
b6866318 KK	37
54a19b4d MCC	38	== =====================================
	39	19 flush requests completed successfully
	40	20 time spent flushing
	41	== =====================================
b6866318	42
4f4cfa6c	43	For more details refer to Documentation/admin-guide/iostats.rst