[fio.git] / examples / ssd-steadystate.fio

# Get a decent idea about the steady state performance of an SSD.
#
# First we sequentially write the drive. Then we completely
# overwrite the device again, this time randomly at 4K. The former gives
# us a good idea of the ideal write performance, you should see flat graph
# of steady write performance. The latter we would expect to start out at
# approximately the same rate as the sequential fill, but at some point
# hit a write cliff and hit steady state. The latency numbers of the steady
# state also provide a good idea of what kind of latencies to expect when
# the device is pushed to steady state instead of peak benchmark-like
# numbers that are usually reported.
#
# Note that this is a DESTRUCTIVE test. It operates on the device itself.
# It's not destructive in the sense that it will ruin the device, but
# whatever data you have on there will be gone.
#
[global]
ioengine=libaio
direct=1
group_reporting
filename=/dev/fioa

[sequential-fill]
description=Sequential fill phase
rw=write
iodepth=16
bs=1M

[random-write-steady]
stonewall
description=Random write steady state phase
rw=randwrite
bs=4K
iodepth=32
numjobs=4
write_bw_log=fioa-steady-state
Commit	Line	Data
58a525d8 JA	1	# Get a decent idea about the steady state performance of an SSD.
	2	#
	3	# First we sequentially write the drive. Then we completely
	4	# overwrite the device again, this time randomly at 4K. The former gives
	5	# us a good idea of the ideal write performance, you should see flat graph
	6	# of steady write performance. The latter we would expect to start out at
	7	# approximately the same rate as the sequential fill, but at some point
	8	# hit a write cliff and hit steady state. The latency numbers of the steady
	9	# state also provide a good idea of what kind of latencies to expect when
	10	# the device is pushed to steady state instead of peak benchmark-like
	11	# numbers that are usually reported.
	12	#
	13	# Note that this is a DESTRUCTIVE test. It operates on the device itself.
	14	# It's not destructive in the sense that it will ruin the device, but
	15	# whatever data you have on there will be gone.
	16	#
	17	[global]
	18	ioengine=libaio
	19	direct=1
	20	group_reporting
	21	filename=/dev/fioa
	22
	23	[sequential-fill]
	24	description=Sequential fill phase
	25	rw=write
	26	iodepth=16
	27	bs=1M
	28
	29	[random-write-steady]
	30	stonewall
	31	description=Random write steady state phase
	32	rw=randwrite
	33	bs=4K
	34	iodepth=32
	35	numjobs=4
	36	write_bw_log=fioa-steady-state