首先你要確定是不是真正的是因為資料空間佔滿磁碟，經常是因為某個程式的日誌佔滿了空間。當發現磁碟滿了以後不要著急，使用以下命令從根目錄開始排除查詢哪個資料夾最大：
du --max-depth=1
找到最大的目錄後，進入目錄再執行上面的命令，逐步就找到大空間的檔案夾了，如果是日誌檔案刪除了就可以了。
下面是du命令的詳細用法：

用法：du [選項]... [檔案]...
或：du [選項]... --files0-from=F
總結每個<檔案>的磁碟用量，目錄則取總用量。

長選項必須用的引數在使用短選項時也是必須的。
-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 顯示此幫助資訊並退出
--version 輸出版本資訊並退出