首先你要确定是不是真正的是因为数据空间占满磁盘，经常是因为某个程序的日志占满了空间。当发现磁盘满了以后不要着急，使用以下命令从根目录开始排除查找哪个文件夹最大：
du --max-depth=1
找到最大的目录后，进入目录再执行上面的命令，逐步就找到大空间的文件夹了，如果是日志文件删除了就可以了。
下面是du命令的详细用法：
用法：du [选项]... [文件]...
或：du [选项]... --files0-from=F
总结每个<文件>的磁盘用量，目录则取总用量。
长选项必须用的参数在使用短选项时也是必须的。
-a, --all write counts for all files, not just directories
--apparent-size print apparent sizes, rather than disk usage; although
the apparent size is usually smaller, it may be
larger due to holes in (`sparse') files, internal
fragmentation, indirect blocks, and the like
-B, --block-size=SIZE use SIZE-byte blocks
-b, --bytes equivalent to `--apparent-size --block-size=1'
-c, --total produce a grand total
-D, --dereference-args dereference FILEs that are symbolic links
--files0-from=F summarize disk usage of the NUL-terminated file
names specified in file F
-H like --si, but also evokes a warning; will soon
change to be equivalent to --dereference-args (-D)
-h, --human-readable print sizes in human readable format (e.g., 1K 234M 2G)
--si like -h, but use powers of 1000 not 1024
-k like --block-size=1K
-l, --count-links count sizes many times if hard linked
-m like --block-size=1M
-L, --dereference dereference all symbolic links
-P, --no-dereference don't follow any symbolic links (this is the default)
-0, --null end each output line with 0 byte rather than newline
-S, --separate-dirs do not include size of subdirectories
-s, --summarize display only a total for each argument
-x, --one-file-system skip directories on different file systems
-X FILE, --exclude-from=FILE Exclude files that match any pattern in FILE.
--exclude=PATTERN Exclude files that match PATTERN.
--max-depth=N print the total for a directory (or file, with --all)
only if it is N or fewer levels below the command
line argument; --max-depth=0 is the same as
--summarize
--time show time of the last modification of any file in the
directory, or any of its subdirectories
--time=WORD show time as WORD instead of modification time:
atime, access, use, ctime or status
--time-style=STYLE show times using style STYLE:
full-iso, long-iso, iso, +FORMAT
FORMAT is interpreted like `date'
--help 显示此帮助信息并退出
--version 输出版本信息并退出
[大小]可以是以下的单位(单位前可加上整数)：
kB 1000，K 1024，MB 1000000，M 1048576，还有 G、T、P、E、Z、Y。