1： 如何查找大文件？
其实很多时候，你需要了解当前系统下有哪些大文件，比如文件大小超过100M或1G（阀值视具体情况而定）。那么如何把这些大文件搜索出来呢？例如我要搜索当前目录下，超过800M大小的文件
[root@getlnx01 u03]# pwd
/u03
[root@getlnx01 u03]# find . -type f -size +800M
./flash_recovery_area/backup/backupsets/ora_df873519197_s46815_s1
./flash_recovery_area/backup/backupsets/ora_df873523646_s46822_s1
./flash_recovery_area/backup/backupsets/ora_df873521714_s46818_s1
./flash_recovery_area/backup/backupsets/ora_df873522876_s46820_s1
./flash_recovery_area/backup/backupsets/ora_df873517396_s46813_s1
./flash_recovery_area/backup/backupsets/ora_df873523321_s46821_s1
./flash_recovery_area/backup/backupsets/ora_df873515765_s46811_s1
./flash_recovery_area/backup/backupsets/ora_df873520789_s46817_s1
./flash_recovery_area/backup/backupsets/ora_df873524162_s46823_s1
./flash_recovery_area/backup/backupsets/ora_df873518302_s46814_s1
./flash_recovery_area/backup/backupsets/ora_df873519953_s46816_s1
./flash_recovery_area/backup/backupsets/ora_df873516500_s46812_s1
./flash_recovery_area/backup/backupsets/ora_df873513413_s46809_s1
./flash_recovery_area/backup/backupsets/ora_df873514789_s46810_s1
./oradata/epps/invsubmat_d08.dbf
./oradata/epps/gmtinv_d08.dbf
./oradata/epps/gmtinv_x01.dbf
./oradata/epps/undotbs02.dbf
./oradata/epps/gmtinv_d07.dbf
./oradata/epps/undotbs01.dbf
./oradata/epps/gmtinv_x02.dbf
如上命令所示，我们仅仅能看到超过800M大小的文件的文件名称，但是对文件的信息（例如，文件大小、文件属性）一无所知，那么能否更详细显示一些文件属性或信息呢，当然可以，如下所示
[root@getlnx01 u03]# find . -type f -size +800M -print0 | xargs -0 ls -l
-rw-r----- 1 oracle oinstall 2782846976 Mar 6 11:51 ./flash_recovery_area/backup/backupsets/ora_df873513413_s46809_s1
-rw-r----- 1 oracle oinstall 1878433792 Mar 6 11:53 ./flash_recovery_area/backup/backupsets/ora_df873514789_s46810_s1
-rw-r----- 1 oracle oinstall 1378492416 Mar 6 11:54 ./flash_recovery_area/backup/backupsets/ora_df873515765_s46811_s1
-rw-r----- 1 oracle oinstall 1641381888 Mar 6 11:56 ./flash_recovery_area/backup/backupsets/ora_df873516500_s46812_s1
-rw-r----- 1 oracle oinstall 1564065792 Mar 6 11:58 ./flash_recovery_area/backup/backupsets/ora_df873517396_s46813_s1
-rw-r----- 1 oracle oinstall 1663492096 Mar 6 12:00 ./flash_recovery_area/backup/backupsets/ora_df873518302_s46814_s1
-rw-r----- 1 oracle oinstall 1368244224 Mar 6 12:02 ./flash_recovery_area/backup/backupsets/ora_df873519197_s46815_s1
-rw-r----- 1 oracle oinstall 1629069312 Mar 6 12:04 ./flash_recovery_area/backup/backupsets/ora_df873519953_s46816_s1
-rw-r----- 1 oracle oinstall 1629954048 Mar 6 12:06 ./flash_recovery_area/backup/backupsets/ora_df873520789_s46817_s1
-rw-r----- 1 oracle oinstall 1202192384 Mar 6 12:07 ./flash_recovery_area/backup/backupsets/ora_df873521714_s46818_s1
-rw-r----- 1 oracle oinstall 1189388288 Mar 6 12:10 ./flash_recovery_area/backup/backupsets/ora_df873522876_s46820_s1
-rw-r----- 1 oracle oinstall 1089257472 Mar 6 12:11 ./flash_recovery_area/backup/backupsets/ora_df873523321_s46821_s1
-rw-r----- 1 oracle oinstall 1097687040 Mar 6 12:12 ./flash_recovery_area/backup/backupsets/ora_df873523646_s46822_s1
-rw-r----- 1 oracle oinstall 1051009024 Mar 6 12:13 ./flash_recovery_area/backup/backupsets/ora_df873524162_s46823_s1
-rw-r----- 1 oracle oinstall 4294975488 Apr 3 15:07 ./oradata/epps/gmtinv_d07.dbf
-rw-r----- 1 oracle oinstall 4194312192 Apr 1 22:36 ./oradata/epps/gmtinv_d08.dbf
-rw-r----- 1 oracle oinstall 4294975488 Apr 3 15:54 ./oradata/epps/gmtinv_x01.dbf
-rw-r----- 1 oracle oinstall 4294975488 Apr 3 15:57 ./oradata/epps/gmtinv_x02.dbf
-rw-r----- 1 oracle oinstall 4294975488 Apr 1 22:35 ./oradata/epps/invsubmat_d08.dbf
-rw-r----- 1 oracle oinstall 8589942784 Apr 4 09:55 ./oradata/epps/undotbs01.dbf
-rw-r----- 1 oracle oinstall 8589942784 Apr 4 09:15 ./oradata/epps/undotbs02.dbf
当我们只需要查找超过800M大小文件，并显示查找出来文件的具体大小，可以使用下面命令
[root@getlnx01 u03]# find . -type f -size +800M -print0 | xargs -0 du -h
1.3G ./flash_recovery_area/backup/backupsets/ora_df873519197_s46815_s1
1.1G ./flash_recovery_area/backup/backupsets/ora_df873523646_s46822_s1
1.2G ./flash_recovery_area/backup/backupsets/ora_df873521714_s46818_s1
1.2G ./flash_recovery_area/backup/backupsets/ora_df873522876_s46820_s1
1.5G ./flash_recovery_area/backup/backupsets/ora_df873517396_s46813_s1
1.1G ./flash_recovery_area/backup/backupsets/ora_df873523321_s46821_s1
1.3G ./flash_recovery_area/backup/backupsets/ora_df873515765_s46811_s1
1.6G ./flash_recovery_area/backup/backupsets/ora_df873520789_s46817_s1
1004M ./flash_recovery_area/backup/backupsets/ora_df873524162_s46823_s1
1.6G ./flash_recovery_area/backup/backupsets/ora_df873518302_s46814_s1
1.6G ./flash_recovery_area/backup/backupsets/ora_df873519953_s46816_s1
1.6G ./flash_recovery_area/backup/backupsets/ora_df873516500_s46812_s1
2.6G ./flash_recovery_area/backup/backupsets/ora_df873513413_s46809_s1
1.8G ./flash_recovery_area/backup/backupsets/ora_df873514789_s46810_s1
4.1G ./oradata/epps/invsubmat_d08.dbf
4.0G ./oradata/epps/gmtinv_d08.dbf
4.1G ./oradata/epps/gmtinv_x01.dbf
8.1G ./oradata/epps/undotbs02.dbf
4.1G ./oradata/epps/gmtinv_d07.dbf
8.1G ./oradata/epps/undotbs01.dbf
4.1G ./oradata/epps/gmtinv_x02.dbf
如果你还需要对查找结果按照文件大小做一个排序，那么可以使用下面命令
[root@getlnx01 u03]# find . -type f -size +800M -print0 | xargs -0 du -h | sort -nr
1004M ./flash_recovery_area/backup/backupsets/ora_df873524162_s46823_s1
8.1G ./oradata/epps/undotbs02.dbf
8.1G ./oradata/epps/undotbs01.dbf
4.1G ./oradata/epps/invsubmat_d08.dbf
4.1G ./oradata/epps/gmtinv_x02.dbf
4.1G ./oradata/epps/gmtinv_x01.dbf
4.1G ./oradata/epps/gmtinv_d07.dbf
4.0G ./oradata/epps/gmtinv_d08.dbf
2.6G ./flash_recovery_area/backup/backupsets/ora_df873513413_s46809_s1
1.8G ./flash_recovery_area/backup/backupsets/ora_df873514789_s46810_s1
1.6G ./flash_recovery_area/backup/backupsets/ora_df873520789_s46817_s1
1.6G ./flash_recovery_area/backup/backupsets/ora_df873519953_s46816_s1
1.6G ./flash_recovery_area/backup/backupsets/ora_df873518302_s46814_s1
1.6G ./flash_recovery_area/backup/backupsets/ora_df873516500_s46812_s1
1.5G ./flash_recovery_area/backup/backupsets/ora_df873517396_s46813_s1
1.3G ./flash_recovery_area/backup/backupsets/ora_df873519197_s46815_s1
1.3G ./flash_recovery_area/backup/backupsets/ora_df873515765_s46811_s1
1.2G ./flash_recovery_area/backup/backupsets/ora_df873522876_s46820_s1
1.2G ./flash_recovery_area/backup/backupsets/ora_df873521714_s46818_s1
1.1G ./flash_recovery_area/backup/backupsets/ora_df873523646_s46822_s1
1.1G ./flash_recovery_area/backup/backupsets/ora_df873523321_s46821_s1
不过如上截图所示，有时候排列的顺序并不完全是按大小一致，这个是因为du命令的参数h所致，你可以统一使用使用MB来显示，这样就能解决这个问题。到这里，这个在Linux系统查找大文件的命令已经非常完美了，当然如果你还有很多的需求，那么可以在这个命令上做修改、调整.
2: 如何查找Linux下的大目录
譬如有时候磁盘空间告警了，而你平时又疏于管理、监控文件的增长，那么我需要快速的了解哪些目录变得比较大，那么此时我们可以借助du命令来帮我们解决这个问题。
[root@getlnx01 u03]# du -h --max-depth=1
16K ./lost+found
33G ./flash_recovery_area
37G ./oradata
70G .
如果你想知道flash_recovery_area目录下面有哪些大文件夹，那么可以将参数max-depth=2 ，如果你想对搜索出来的结果进行排序，那么可以借助于sort命令。如下所示
[root@getlnx01 u03]# du -h --max-depth=2 | sort -n
3.5G ./flash_recovery_area/EPPS
16K ./lost+found
29G ./flash_recovery_area/backup
33G ./flash_recovery_area
37G ./oradata
37G ./oradata/epps
70G .
[root@getlnx01 u03]# du -hm --max-depth=2 | sort -n
1 ./lost+found
3527 ./flash_recovery_area/EPPS
29544 ./flash_recovery_area/backup
33070 ./flash_recovery_area
37705 ./oradata
37705 ./oradata/epps
70775 .
[root@getlnx01 u03]# cd /
[root@getlnx01 /]# du -hm --max-depth=2 | sort -n
有时候搜索出来的结果太多了（譬如，我从根目录开始搜索），一直在刷屏，如果我只想查出最大的12个文件夹，怎么办呢？此时就要借助head命令来显示了
[root@getlnx01 /]# du -hm --max-depth=2 | sort -nr | head -12
407480 .
167880 ./u04
158685 ./u02/oradata
158685 ./u02
152118 ./u04/oradata
70775 ./u03
37705 ./u03/oradata
33070 ./u03/flash_recovery_area
5995 ./u01/app
5995 ./u01
3551 ./usr
1558 ./usr/share
[root@getlnx01 /]#
参考资料：