Disk
Material
- HDD: hard disk drive, sequencial r/w by plaster spin
- SSD: solid state drive, radom r/w, ~500Mbps, ~60MBps
https://windows101tricks.com/ssd-vs-hdd-which-is-better-for-you/
Data Path to Memory/CPU
- SATA-3/AHCI: ~6Gbps \n
- PCI-E/NVMe: ~8Gbps \n
https://baijiahao.baidu.com/s?id=1616207956596122967&wfr=spider&for=pc \n
Command for Disk
#Check IO workload
#iostat
!34 $ iostat -d sdb -m 1 3
Linux 3.10.0-327.el7.x86_64 (stgxxx.stg.fwxxx.net) 04/10/2019 _x86_64_ (32 CPU)
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
sdb 30.98 0.93 1.26 58240167 78445236
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
sdb 67.00 2.36 0.04 2 0
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
sdb 36.00 1.17 0.03 1 0
#sar
!59 $ sar -B #[interval s] [times] default interval 10min
Linux 3.10.0-327.18.2.el7.x86_64 (stgxxx.stg.fwxxx.net) 04/10/2019 _x86_64_ (32 CPU)
12:00:01 AM pgpgin/s pgpgout/s fault/s majflt/s pgfree/s pgscank/s pgscand/s pgsteal/s %vmeff
12:10:01 AM 17464.27 13875.99 8911.24 0.39 6596.76 4586.96 288.44 4874.21 99.98
12:20:01 AM 17685.64 24660.67 17401.12 1.02 10334.51 4859.92 681.59 5540.41 99.98
12:30:01 AM 41152.40 24461.72 32299.13 1.11 29265.72 10849.65 823.70 11670.80 99.98
#pgpgin/s: page in x kilobytes from disk per seconds
#pgpgout/s: page out x kilobytes from disk per seconds
来源：oschina
链接：https://my.oschina.net/u/3733861/blog/3034528