Linux的df命令

帮助文档

openailab@openailab-System-Product-Name:~/oaldata$ df --help
Usage: df [OPTION]... [FILE]...
Show information about the file system on which each FILE resides,
or all file systems by default.

Mandatory arguments to long options are mandatory for short options too.
  -a, --all             include pseudo, duplicate, inaccessible file systems
  -B, --block-size=SIZE  scale sizes by SIZE before printing them; e.g.,
                           '-BM' prints sizes in units of 1,048,576 bytes;
                           see SIZE format below
  -h, --human-readable  print sizes in powers of 1024 (e.g., 1023M)
  -H, --si              print sizes in powers of 1000 (e.g., 1.1G)
  -i, --inodes          list inode information instead of block usage
  -k                    like --block-size=1K
  -l, --local           limit listing to local file systems
      --no-sync         do not invoke sync before getting usage info (default)
      --output[=FIELD_LIST]  use the output format defined by FIELD_LIST,
                               or print all fields if FIELD_LIST is omitted.
  -P, --portability     use the POSIX output format
      --sync            invoke sync before getting usage info
      --total           elide all entries insignificant to available space,
                          and produce a grand total
  -t, --type=TYPE       limit listing to file systems of type TYPE
  -T, --print-type      print file system type
  -x, --exclude-type=TYPE   limit listing to file systems not of type TYPE
  -v                    (ignored)
      --help     display this help and exit
      --version  output version information and exit

Display values are in units of the first available SIZE from --block-size,
and the DF_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.
Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).

The SIZE argument is an integer and optional unit (example: 10K is 10*1024).
Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB,... (powers of 1000).

FIELD_LIST is a comma-separated list of columns to be included.  Valid
field names are: 'source', 'fstype', 'itotal', 'iused', 'iavail', 'ipcent',
'size', 'used', 'avail', 'pcent', 'file' and 'target' (see info page).

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Full documentation at: <http://www.gnu.org/software/coreutils/df>
or available locally via: info '(coreutils) df invocation'

有个疑惑

如图，我的Linux系统，有1T固态硬盘和3.6T机械硬盘，我想知道“/home/openailab/oaldata/datasets”路径使用哪个磁盘进行存储。我该怎么做？

Linux文件存储在哪里？

一个想法

从挂载情况来看，根目录挂载在固态硬盘上，也就是所有路径的起点 “/”。如果这样的话，目测路径“/home/openailab/oaldata/datasets”的存储，使用的就是固态硬盘。

一个实践

为了验证这个想法，我们往这个路径下存东西，先存他一个T。

结果没到1个T，固态硬盘就满了。这也就验证了我的想法，该路径使用的是固态硬盘存储。

两个需求

1、我该如何判断该路径使用的是哪个磁盘？

通过帮助文档，df命令带了一个参数file：df [OPTION]… [FILE]…

所以，可以把这个file加上，来查看挂载目录：

df -h /home/openailab/oaldata

2、我想让该路径使用机械硬盘，我该如何做？

因为这个路径下面已经存有东西，如果直接挂载的话，将会导致该目录下的文件直接丢失。因此，我们需要进行备份，请看我下一篇博客：mount命令。