1. 什么是HDDs
HDDs have been around over 60 years since IBM introduced them in 1956. The first disk drive was the size of a car, stored a mere 3.75 megabytes, and cost $300,000 in today’s dollars. 自IBM于1956年推出硬盘驱动器以来,硬盘驱动器已经存在了60多年。第一个磁盘驱动器的大小与汽车相当,仅存储3.75兆字节,今天的成本为30万美元。
IBM 350 Disk Storage System — 3.75MB in 1956
2. 什么是SSDs
SSDs go back almost as far as HDDs, with the first semiconductor storage device compatible with a hard drive interface introduced in 1978, the StorageTek 4305.
固态硬盘几乎与硬盘驱动器一样,第一个半导体存储设备与1978年推出的硬盘驱动器接口兼容,即StorageTek 4305
Storage Technology 4305 SSD — 45MB in 1978
SSD circuit board
a. 通过检查是否支持旋转判断
cat /sys/block/dm-0/queue/rotational
如果返回0表示是SSD硬盘,如果是1表示HDD硬盘
b. 通过lsblk 命令查找,该命令位于util-linux包
[root@k8s-uat-test-node01 ~]# lsblk -o NAME,MOUNTPOINT,MODEL,ROTA
NAME MOUNTPOINT MODEL ROTA
sr0 QEMU DVD-ROM 1
vda 1
├─vda1 /boot 1
└─vda2 1
├─centos-root / 1
├─centos-swap 1
└─centos-service /service 1
c. 通过smartctl命令查找
smartctl -a /dev/sdb
如果有Rotation Rate: Solid State Device 信息显示说明是SSD
https://unix.stackexchange.com/questions/65595/how-to-know-if-a-disk-is-an-ssd-or-an-hdd
d. 认识磁盘io
[root@k8s-uat-test-node01 ~]# cat /proc/diskstats
252 0 vda 84494184 201007 10734352824 15102148 1974560 273246 107437596 7484717 0 3615765 16077475
252 1 vda1 2007 0 52412 941 107 3 31355 676 0 955 1338
252 2 vda2 84492088 201007 10734295004 15101164 1607040 273243 107406241 7244181 0 3646663 16439879
11 0 sr0 18 0 2056 94 0 0 0 0 0 81 94
253 0 dm-0 83039947 0 9722932166 14647652 1270507 0 52492890 5951809 0 4103211 20685192
253 1 dm-1 88 0 4656 13 0 0 0 0 0 13 13
253 2 dm-2 2681466 0 1011356006 855384 616464 0 54913351 6430878 0 783796 7307385
https://www.kernel.org/doc/Documentation/iostats.txt
http://linuxperf.com/?p=156