1.查看磁盘
使用df -h，查看当前硬盘信息，但不会显示未挂载的磁盘
[root@node1 ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/mapper/centos-root 1.1T 80G 971G 8% /
devtmpfs 126G 0 126G 0% /dev
tmpfs 126G 0 126G 0% /dev/shm
tmpfs 126G 3.3M 126G 1% /run
tmpfs 126G 0 126G 0% /sys/fs/cgroup
/dev/sde3 1.8T 25G 1.7T 2% /data12
/dev/sdd4 1.8T 109G 1.6T 7% /data9
/dev/sdc1 1.8T 1.4T 338G 81% /data3
/dev/sdc2 1.8T 1.5T 306G 83% /data4
/dev/sdd3 1.8T 126G 1.6T 8% /data8
/dev/sdb1 1.8T 1.5T 243G 87% /data1
/dev/sdd2 1.8T 117G 1.6T 7% /data7
/dev/sdb2 1.8T 1.5T 249G 86% /data2
/dev/sdd1 1.8T 881G 861G 51% /data6
/dev/sde2 1.8T 16G 1.7T 1% /data11
/dev/sde1 1.8T 20G 1.7T 2% /data10
/dev/sde4 1.8T 95G 1.7T 6% /data5
/dev/mapper/centos-home 2.6T 1.1T 1.5T 43% /home
/dev/sda2 1014M 214M 801M 22% /boot
/dev/sda1 200M 11M 189M 6% /boot/efi
tmpfs 26G 0 26G 0% /run/user/0
cm_processes 126G 8.0G 118G 7% /run/cloudera-scm-agent/process
.....
使用fdisk -l，查看所有磁盘信息，显示未挂载的磁盘
[root@node1 ~]# fdisk -l
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
磁盘 /dev/sde：8001.6 GB, 8001563222016 字节，15628053168 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 4096 字节
I/O 大小(最小/最佳)：4096 字节 / 4096 字节
磁盘标签类型：gpt
Disk identifier: 7602EB92-8E94-4926-83AC-239615E1127A
# Start End Size Type Name
1 34 3906250000 1.8T Microsoft basic primary
Partition 1 does not start on physical sector boundary.
2 3906250752 7812499455 1.8T Microsoft basic primary
3 7812499456 11718750207 1.8T Microsoft basic primary
4 11718750208 15625000959 1.8T Microsoft basic primary
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
磁盘 /dev/sdd：8001.6 GB, 8001563222016 字节，15628053168 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 4096 字节
I/O 大小(最小/最佳)：4096 字节 / 4096 字节
磁盘标签类型：gpt
Disk identifier: D6DD4D62-3760-43B8-84E2-C2E1EA58F25B
# Start End Size Type Name
1 34 3906250000 1.8T Microsoft basic primary
Partition 1 does not start on physical sector boundary.
2 3906250752 7812499455 1.8T Microsoft basic primary
3 7812499456 11718750207 1.8T Microsoft basic primary
4 11718750208 15625000959 1.8T Microsoft basic primary
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
磁盘 /dev/sda：4000.8 GB, 4000787030016 字节，7814037168 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：gpt
Disk identifier: BF2C7713-20A2-4993-9067-F44F0C957290
# Start End Size Type Name
1 2048 411647 200M EFI System EFI System Partition
2 411648 2508799 1G Microsoft basic
3 2508800 7814035455 3.7T Linux LVM
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
磁盘 /dev/sdc：4000.8 GB, 4000787030016 字节，7814037168 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：gpt
Disk identifier: 47F028E4-71B5-45EA-8550-0DA97E0C2D60
# Start End Size Type Name
1 2048 3907018751 1.8T Microsoft basic primary
2 3907018752 7814035455 1.8T Microsoft basic primary
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
磁盘 /dev/sdb：4000.8 GB, 4000787030016 字节，7814037168 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：gpt
Disk identifier: 7CC7B9DF-1EEC-4B3F-8296-B9F4D3E6EDFF
# Start End Size Type Name
1 2048 3907018751 1.8T Microsoft basic primary
2 3907018752 7814035455 1.8T Microsoft basic primary
........
2.查看磁盘类型
使用cat /sys/block/sda/queue/rotational，命令中的sda是磁盘名称。
返回结果：
返回0：SSD盘(固态硬盘)
返回1：SATA盘(使用SATA口的机械硬盘)
[root@node1 ~]# cat /sys/block/sda/queue/rotational
1
3.SSD盘和SATA盘优缺点
SATA机械硬盘：
- 优点：容量大，价格低，技术成熟，存储可靠。
- 缺点：速度相对于固态较慢，介质越到边缘速度越慢，安全性不高（发生断电、碰撞容易坏），读取数据有轻微响声。
SSD固体硬盘：
- 优点：无噪音，体积小，速度快，更省电 ，重量轻 ，发热小。
- 缺点：容量相对小 ，价格昂贵。