Chapter 16 Managing Disk Use (Tasks)
This chapter describes how to optimize disk space by locating unused files and large directories.
This is a list of the step-by-step instructions in this chapter.
Displaying Information About Files and Disk Space
This table summarizes the commands available for displaying information about file size and disk space.
|
Command |
Man Page |
Description |
|---|---|---|
|
df |
Reports the number of free disk blocks and files. |
|
|
du |
Summarizes disk space allocated to each subdirectory. |
|
|
find -size |
Searches recursively through a directory based on the size specified with the -size option. |
|
|
ls -lh |
Lists the size of a file in the power of 1024. |
How to Display Information About Files and Disk Space
Display information about how disk space is used by using the df command.
$ df [directory] [-h] [-t] [-t] |
|
df |
With no options, lists all mounted file systems and their device names, the number of 512-byte blocks used, and the number of files. |
|
directory |
Specifies the directory whose file system you want to check. |
|
-h |
Displays disk space in the power of 1024. |
|
-t |
Displays the total blocks as well as the blocks used for all mounted file systems. |
Examples—Displaying Information About File Size and Disk Space
In the following example, all the file systems listed are locally mounted except for /usr/dist, which is mounted remotely from the system venus.
$ df / (/dev/dsk/c0t0d0s0 ): 287530 blocks 92028 files /usr (/dev/dsk/c0t0d0s6 ): 1020214 blocks 268550 files /proc (/proc ): 0 blocks 878 files /dev/fd (fd ): 0 blocks 0 files /etc/mnttab (mnttab ): 0 blocks 0 files /var/run (swap ): 396016 blocks 9375 files /tmp (swap ): 396016 blocks 9375 files /opt (/dev/dsk/c0t0d0s5 ): 381552 blocks 96649 files /export/home (/dev/dsk/c0t0d0s7 ): 434364 blocks 108220 files /usr/dist (venus:/usr/dist ):14750510 blocks 2130134 files |
In the following example, file system information is displayed in 1024 bytes.
$ df -h Filesystem size used avail capacity Mounted on /dev/dsk/c0t0d0s0 1.9G 58M 1.8G 4% / /dev/dsk/c0t0d0s6 2.5G 765M 1.7G 1% /usr /proc 0K 0K 0K 0% /proc fd 0K 0K 0K 0% /dev/fd mnttab 0K 0K 0K 0% /etc/mnttab swap 2.1G 24K 2.1G 1% /var/run swap 2.1G 0K 2.1G 0% /tmp /dev/dsk/c0t0d0s5 1.9G 12M 1.8G 1% /opt /dev/dsk/c0t0d0s7 1.9G 10K 1.8G 1% /export/home |
Note –
Although /proc and /tmp are local file systems, they are not UFS file systems. /proc is a PROCFS file system, /var/run and /tmp are TMPFS file systems, and /etc/mnttab is a MNTFS file system.
The following example shows a list of all mounted file systems, device names, total 512-byte blocks used, and number of files. The second line of each two-line entry displays the total number of blocks and files allocated for the file system.
$ df -t
/ (/dev/dsk/c0t0d0s0 ): 287530 blocks 92028 files
total: 385614 blocks 96832 files
/usr (/dev/dsk/c0t0d0s6 ): 1020214 blocks 268550 files
total: 2381102 blocks 300288 files
/proc (/proc ): 0 blocks 879 files
total: 0 blocks 924 files
/dev/fd (fd ): 0 blocks 0 files
total: 0 blocks 72 files
/etc/mnttab (mnttab ): 0 blocks 0 files
total: 0 blocks 1 files
/var/run (swap ): 396112 blocks 9375 files
total: 396112 blocks 9395 files
/tmp (swap ): 396112 blocks 9375 files
total: 396128 blocks 9395 files
/opt (/dev/dsk/c0t0d0s5 ): 381552 blocks 96649 files
total: 385614 blocks 96832 files
/export/home (/dev/dsk/c0t0d0s7 ): 434364 blocks 108220 files
total: 434382 blocks 108224 files
/usr/dist (venus:/usr/dist ): 14750510 blocks 2130134 files
total: 41225162 blocks 2482176 files
|
Checking the Size of Files
You can check the size of files and sort them by using the ls command. You can find files that exceed a size limit by using the find command. For more information, see ls(1) and find(1).
How to Display the Size of Files
-
Change to the directory where the files you want to check are located.
-
Display the size of the files.
$ ls [-lh] [-s]
-l
Displays a list of files and directories in long format, showing the sizes in bytes. (See the example that follows.)
-h
Scales file and directory sizes into Kbytes, Mbytes, Gbytes, or Terabytes when the file or directory size is larger than 1024 bytes. This option also modifies the output displayed by the -o, -n, -@, and -g options to display file or directory sizes in the new format. For more information, see ls(1).
-s
Displays a list of the files and directories, showing the sizes in blocks.
Examples—Displaying the Size of Files
The following example shows that the lastlog and messages files are larger than the other files in the /var/adm directory.
$ cd /var/adm $ ls -lh total 148 drwxrwxr-x 5 adm adm 512 Nov 26 09:39 acct/ -rw------- 1 uucp bin 0 Nov 26 09:25 aculog drwxr-xr-x 2 adm adm 512 Nov 26 09:25 exacct/ -r--r--r-- 1 root other 342K Nov 26 13:56 lastlog drwxr-xr-x 2 adm adm 512 Nov 26 09:25 log/ -rw-r--r-- 1 root root 20K Nov 26 13:55 messages drwxr-xr-x 2 adm adm 512 Nov 26 09:25 passwd/ drwxrwxr-x 2 adm sys 512 Nov 26 09:39 sa/ drwxr-xr-x 2 root sys 512 Nov 26 09:49 sm.bin/ -rw-rw-rw- 1 root bin 0 Nov 26 09:25 spellhist drwxr-xr-x 2 root sys 512 Nov 26 09:25 streams/ -rw-r--r-- 1 root bin 3.3K Nov 26 13:56 utmpx -rw-r--r-- 1 root root 0 Nov 26 10:17 vold.log -rw-r--r-- 1 adm adm 19K Nov 26 13:56 wtmpx |
The following example shows that the lpsched.1 file uses two blocks.
$ cd /var/lp/logs $ ls -s total 2 0 lpsched 2 lpsched.1 |
How to Find Large Files
-
Display the size of files in blocks from largest to smallest.
$ ls -s | sort -nr | more
sort -nr
Sorts the list of files by block size from largest to smallest.
Example—Finding Large Files
In the following example, the lastlog and messages files are the largest files in the /var/adm directory.
$ cd /var/adm $ ls -s | sort -nr | more 48 lastlog 30 messages 24 wtmpx 18 pacct 8 utmpx 2 vold.log 2 sulog 2 sm.bin/ 2 sa/ 2 passwd/ 2 pacct1 2 log/ 2 acct/ 0 spellhist 0 aculog total 144 |
How to Find Files That Exceed a Specified Size Limit
To locate and display the names of files that exceed a specified size, use the find command.
$ find directory -size +nnn |
|
directory |
Identifies the directory you want to search. |
|
-size +nnn |
Is a number of 512-byte blocks. Files that exceed this size are listed. |
Example—Finding Files That Exceed a Specified Size Limit
The following example shows how to find files larger than 400 blocks in the current working directory.
$ find . -size +400 -print ./Howto/howto.doc ./Howto/howto.doc.backup ./Howto/howtotest.doc ./Routine/routineBackupconcepts.doc ./Routine/routineIntro.doc ./Routine/routineTroublefsck.doc ./.record ./Mail/pagination ./Config/configPrintadmin.doc ./Config/configPrintsetup.doc ./Config/configMailappx.doc ./Config/configMailconcepts.doc ./snapshot.rs |
Checking the Size of Directories
You can display the size of directories by using the du command and options. Additionally, you can find the amount of disk space used by user accounts on local UFS file systems by using the quot command. For more information about these commands, see du(1) and quot(1M).
How to Display the Size of Directories, Subdirectories, and Files
Display the size of one or more directories, subdirectories, and files by using the du command. Sizes are displayed in 512-byte blocks.
$ du [-as] [directory ...] |
|
du |
Displays the size of each directory you specify, including each subdirectory beneath it. |
|
-a |
Displays the size of each file and subdirectory, and the total number of blocks contained in the specified directory. |
|
-s |
Displays the total number of blocks contained in the specified directory. |
|
-h |
Displays the size of each directory in 1024 bytes. |
|
-H |
Displays the size of each directory in 1000 bytes. |
|
directory ... |
Identifies one or more directories you want to check. |
Examples—Displaying the Size of Directories, Subdirectories, and Files
The following example shows the total sizes of two directories.
$ du -s /var/adm /var/spool/lp 130 /var/adm 40 /var/spool/lp |
The following example shows the sizes of two directories, all of the subdirectories and files they contain, and the total number of blocks contained in each directory.
$ du /var/adm /var/spool/lp 2 /var/adm/log 2 /var/adm/passwd 2 /var/adm/acct/fiscal 2 /var/adm/acct/nite 2 /var/adm/acct/sum 8 /var/adm/acct 2 /var/adm/sa 2 /var/adm/sm.bin 130 /var/adm 4 /var/spool/lp/admins 2 /var/spool/lp/fifos/private 2 /var/spool/lp/fifos/public 6 /var/spool/lp/fifos 2 /var/spool/lp/requests/starbug 4 /var/spool/lp/requests 2 /var/spool/lp/system 2 /var/spool/lp/tmp/starbug 2 /var/spool/lp/tmp/.net/tmp/starbug 4 /var/spool/lp/tmp/.net/tmp 2 /var/spool/lp/tmp/.net/requests/starbug 4 /var/spool/lp/tmp/.net/requests 10 /var/spool/lp/tmp/.net 14 /var/spool/lp/tmp 40 /var/spool/lp |
The following example shows directory sizes in 1024 bytes.
du -h /usr/share/audio 796K /usr/share/audio/samples/au 797K /usr/share/audio/samples 798K /usr/share/audio |
How to Display the User Ownership of Local UFS File Systems
-
Display users, directories, or file systems, and the number of 1024-byte blocks used.
# quot [-a] [filesystem]
-a
Lists all users of each mounted UFS file system and the number of 1024-byte blocks used.
filesystem
Identifies a UFS file system. Users and the number of blocks used are displayed.
Note –The quot command works only on local UFS file systems.
Example—Displaying the User Ownership of Local UFS File Systems
In the following example, users of the root (/) file system are displayed. Then, users of all mounted UFS file systems are displayed.
# quot /
/dev/rdsk/c0t0d0s0:
43340 root
3142 rimmer
47 uucp
35 lp
30 adm
4 bin
4 daemon
# quot -a
/dev/rdsk/c0t0d0s0 (/):
43340 root
3150 rimmer
47 uucp
35 lp
30 adm
4 bin
4 daemon
/dev/rdsk/c0t0d0s6 (/usr):
460651 root
206632 bin
791 uucp
46 lp
4 daemon
1 adm
/dev/rdsk/c0t0d0s7 (/export/home):
9 root
|
Finding and Removing Old or Inactive Files
Part of the job of cleaning up heavily loaded file systems involves locating and removing files that have not been used recently. You can locate unused files using the ls or find commands. For more information, see ls(1) and find(1).
Other ways to conserve disk space include emptying temporary directories such as the ones located in /var/tmp or /var/spool, and deleting core and crash dump files. For more information about crash dump files, refer to Chapter 28, Managing System Crash Information (Tasks).
How to List the Newest Files
List files, displaying the most recently created or changed files first, by using the ls -t command.
$ ls -t [directory] |
|
-t |
Sorts files by latest time stamp first. |
|
directory |
Identifies the directory you want to search. |
Example—Listing the Newest Files
The following example shows how to use the ls -tl command to locate the most recently created or changed files within the /var/adm directory. The sulog file was created or edited most recently.
$ ls -tl /var/adm total 134 -rw------- 1 root root 315 Sep 24 14:00 sulog -r--r--r-- 1 root other 350700 Sep 22 11:04 lastlog -rw-r--r-- 1 root bin 4464 Sep 22 11:04 utmpx -rw-r--r-- 1 adm adm 20088 Sep 22 11:04 wtmpx -rw-r--r-- 1 root other 0 Sep 19 03:10 messages -rw-r--r-- 1 root other 0 Sep 12 03:10 messages.0 -rw-r--r-- 1 root root 11510 Sep 10 16:13 messages.1 -rw-r--r-- 1 root root 0 Sep 10 16:12 vold.log drwxr-xr-x 2 root sys 512 Sep 10 15:33 sm.bin drwxrwxr-x 5 adm adm 512 Sep 10 15:19 acct drwxrwxr-x 2 adm sys 512 Sep 10 15:19 sa -rw------- 1 uucp bin 0 Sep 10 15:17 aculog -rw-rw-rw- 1 root bin 0 Sep 10 15:17 spellhist drwxr-xr-x 2 adm adm 512 Sep 10 15:17 log drwxr-xr-x 2 adm adm 512 Sep 10 15:17 passwd |
How to Find and Remove Old or Inactive Files
-
Become superuser.
-
Find files that have not been accessed for a specified number of days and list them in a file.
# find directory -type f[-atime + nnn] [-mtime + nnn] -print > filename
directory
Identifies the directory you want to search. Directories below this directory are also searched.
-atime +nnn
Finds files that have not been accessed within the number of days (nnn) you specify.
-mtime +nnn
Finds files that have not been modified within the number of days (nnn) you specify.
filename
Identifies the file that contains the list of inactive files.
-
Remove the inactive files that you listed in the previous step.
# rm `cat filename`
filename identifies the file created in the previous step which contains the list of inactive files.
Example—Finding and Removing Old or Inactive Files
The following example shows files in the /var/adm directory and the subdirectories that have not been accessed in the last 60 days. The /var/tmp/deadfiles file contains the list of inactive files. The rm command removes these inactive files.
# find /var/adm -type f -atime +60 -print > /var/tmp/deadfiles & # more /var/tmp/deadfiles /var/adm/aculog /var/adm/spellhist /var/adm/wtmpx /var/adm/sa/sa13 /var/adm/sa/sa27 /var/adm/sa/sa11 /var/adm/sa/sa23 /var/adm/sulog /var/adm/vold.log /var/adm/messages.1 /var/adm/messages.2 /var/adm/messages.3 # rm `cat /var/tmp/deadfiles` # |
How to Clear Out Temporary Directories
-
Change to the directory to clean out.
# cd directory
Caution – Be sure you are in the right directory before completing step 3. Step 3 deletes all files in the current directory.
-
Delete the files and subdirectories in the current directory.
# rm -r *
-
Change to other directories containing unnecessary temporary or obsolete subdirectories and files, and delete them by repeating Step 3.
Example—Clearing Out Temporary Directories
The following example shows how to clear out the mywork directory, and how to verify that all files and subdirectories were removed.
# cd mywork # ls filea.000 fileb.000 filec.001 # rm -r * # ls # |
How to Find and Delete core Files
-
Change to the directory where you want to search for core files.
-
Find and remove any core files in this directory and its subdirectories.
# find . -name core -exec rm {} \;
Example—Finding and Deleting core Files
The following example shows how to find and remove core files from the jones user account by using the find command.
# cd /home/jones# find . -name core -exec rm {} \;
|
How to Delete Crash Dump Files
Crash dump files can be very large, so if you have enabled your system to store these files, do not retain them for longer than necessary.
-
Change to the directory where crash dump files are stored.
# cd /var/crash/system
Where system identifies a system that created the crash dump files.
Caution – Be sure you are in the right directory before completing step 3. Step 3 deletes all files in the current directory.
-
Remove the crash dump files.
# rm *
-
Verify that the crash dump files are removed.
# ls
Example—Deleting Crash Dump Files
The following example shows how to remove crash dump files from the system venus, and how to verify that the crash dump files were removed.
# cd /var/crash/venus # rm * # ls |
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