hi guys
I meet a unexplaineable problem
I have 2 PCIe SSD card which are in the same type
I do some fio test:
SSD1:
the iostat shows that
I add a blockalign option: blockalign=4k
the iostat shows that
SSD2:
the iostat shows that
I add a blockalign blockalign=4k
the iostat shows that
===========================================================
adding blockalign has a big difference for SSD1
but SSD2 do not have significant performance degrade
does anyone has any ideas?
I meet a unexplaineable problem
I have 2 PCIe SSD card which are in the same type
I do some fio test:
SSD1:
Code:
fio -runtime=300 -ramp_time=0 -numjobs=1 -iodepth=32 -direct=1 -sync=0 -thread -time_based -zero_buffers -buffered=1 -ioengine=posixaio -rw=randread -bs=128k -name=rand_read -size=100g -filename=/dev/nvd0
the iostat shows that
Code:
no align
device r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b
nvd0 11486.7 0.0 1470291.7 0.0 31 2.5 100
Code:
fio -runtime=300 -ramp_time=0 -numjobs=1 -iodepth=32 -direct=1 -sync=0 -thread -time_based -zero_buffers -buffered=1 -ioengine=posixaio -rw=randread -bs=128k -name=rand_read -size=100g -filename=/dev/nvd0 -blockalign=4k
I add a blockalign option: blockalign=4k
the iostat shows that
Code:
device r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b
nvd0 1575.4 0.0 201653.5 0.0 28 19.0 100
SSD2:
Code:
fio -runtime=300 -ramp_time=0 -numjobs=1 -iodepth=32 -direct=1 -sync=0 -thread -time_based -zero_buffers -buffered=1 -ioengine=posixaio -rw=randread -bs=128k -name=rand_read -size=100g -filename=/dev/nvd0
Code:
device r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b
nvd0 10832 0 1386544.0 0.0 2 0 0 2 32 100
Code:
fio -runtime=300 -ramp_time=0 -numjobs=1 -iodepth=32 -direct=1 -sync=0 -thread -time_based -zero_buffers -buffered=1 -ioengine=posixaio -rw=randread -bs=128k -name=rand_read -size=100g -filename=/dev/nvd0 -blockalign=4k
I add a blockalign blockalign=4k
the iostat shows that
Code:
device r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b
nvd0 11131 0 1424882.1 0.0 2 0 0 2 32 100
adding blockalign has a big difference for SSD1
but SSD2 do not have significant performance degrade
does anyone has any ideas?