Improving Linux System Performance with I/O Scheduler Tuning

Improving Linux System Performance with I/O Scheduler Tuning
Тест SSD планировщиков ввода
Why does Ubuntu 16.04 set all drive IO schedulers to “deadline”?


$ cat /sys/block/sda/queue/scheduler
noop deadline [cfq]
$ cat /sys/block/sdb/queue/scheduler
noop deadline [cfq]

$ sudo su root -c "tee /sys/block/sda/queue/scheduler <<< noop"
$ cat /sys/block/sda/queue/scheduler
[noop] deadline cfq

$ sudo hdparm -t /dev/sda

/dev/sda:
 Timing buffered disk reads: 1600 MB in  3.00 seconds = 533.17 MB/sec

$ sudo hdparm -t /dev/sda

/dev/sda:
 Timing buffered disk reads: 1600 MB in  3.00 seconds = 533.24 MB/sec
user@propan:~$



$ sudo hdparm -T /dev/sda

/dev/sda:
 Timing cached reads:   35760 MB in  1.99 seconds = 17996.85 MB/sec

$ sudo hdparm -T /dev/sda

/dev/sda:
 Timing cached reads:   36348 MB in  1.99 seconds = 18294.66 MB/sec



$ sudo su root -c "tee /sys/block/sda/queue/scheduler <<< deadline"
$ cat /sys/block/sda/queue/scheduler
noop [deadline] cfq


$ sudo hdparm -t /dev/sda

/dev/sda:
 Timing buffered disk reads: 1592 MB in  3.00 seconds = 530.37 MB/sec

$ sudo hdparm -t /dev/sda

/dev/sda:
 Timing buffered disk reads: 1592 MB in  3.00 seconds = 530.45 MB/sec
user@propan:~$ sudo hdparm -T /dev/sda



$ sudo hdparm -T /dev/sda

/dev/sda:
 Timing cached reads:   36036 MB in  1.99 seconds = 18137.23 MB/sec
user@propan:~$ sudo hdparm -T /dev/sda


$ sudo hdparm -T /dev/sda

/dev/sda:
 Timing cached reads:   36484 MB in  1.99 seconds = 18364.60 MB/sec
user@propan:~$


$ sudo su root -c "tee /sys/block/sda/queue/scheduler <<< cfq"
$ cat /sys/block/sda/queue/scheduler
noop deadline [cfq]

$ sudo hdparm -t /dev/sda

/dev/sda:
 Timing buffered disk reads: 1600 MB in  3.00 seconds = 533.28 MB/sec

$ sudo hdparm -t /dev/sda

/dev/sda:
 Timing buffered disk reads: 1600 MB in  3.00 seconds = 533.25 MB/sec


$ sudo hdparm -T /dev/sda

/dev/sda:
 Timing cached reads:   35930 MB in  1.99 seconds = 18082.75 MB/sec

$ sudo hdparm -T /dev/sda

/dev/sda:
 Timing cached reads:   35384 MB in  1.99 seconds = 17807.00 MB/sec