Chapter 28 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 Blocks and Files Used
Use the df command and its options to report the number of free disk blocks and files. For more information, see df(1M).
How to Display Information About Blocks, Files, and Disk Space
Display information about how disk space is used by using the df command.
$ df [directory] [-F fstype] [-g] [-k] [-t]
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df
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With no options, lists all mounted file systems and their device names, the number of total 512-byte blocks used, and the number of files.
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directory
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Directory whose file system you want to check. The device name, blocks used, and number of files are displayed.
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-F fstype
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Displays a list of unmounted file systems, their device names, the number of 512-byte blocks used, and the number of files on file systems of type fstype.
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-g
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Displays the statvfs structure for all mounted file systems.
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-k
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Displays a list of file systems, kilobytes used, free kilobytes, percent capacity used, and mount points.
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-t
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Displays total blocks as well as blocks used for all mounted file systems.
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Examples--Displaying Information About Blocks, Files, 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
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In the following example, the file system, total Kbytes, used Kbytes, available Kbytes, percent of capacity used, and mount point are displayed.
$ df -k
Filesystem kbytes used avail capacity Mounted on
/dev/dsk/c0t0d0s0 192807 49042 124485 29% /
/dev/dsk/c0t0d0s6 1190551 680444 450580 61% /usr
/proc 0 0 0 0% /proc
fd 0 0 0 0% /dev/fd
mnttab 0 0 0 0% /etc/mnttab
swap 198056 0 198056 0% /var/run
swap 198064 8 198056 1% /tmp
/dev/dsk/c0t0d0s5 192807 2031 171496 2% /opt
/dev/dsk/c0t0d0s7 217191 9 195463 1% /export/home
venus:/usr/dist 20612581 13237326 6963005 66% /usr/dist
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The following example shows information about the same system as the previous example, but only UFS file system information is displayed.
$ df -F ufs
/ (/dev/dsk/c0t0d0s0 ): 287530 blocks 92028 files
/usr (/dev/dsk/c0t0d0s6 ): 1020214 blocks 268550 files
/opt (/dev/dsk/c0t0d0s5 ): 381552 blocks 96649 files
/export/home (/dev/dsk/c0t0d0s7 ): 434364 blocks 108220 files
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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
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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
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Change the directory to where the files you want to check are located.
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Display the size of the files.
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-l
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Displays a list of files and directories in long format, showing the sizes in bytes.
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-s
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Displays a list of the files and directories, showing the sizes in blocks.
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Examples--Displaying the Size of Files
The following example shows that lastlog and messages are larger than the other files in the /var/adm directory.
$ cd /var/adm
$ ls -l
total 144
drwxrwxr-x 5 adm adm 512 Sep 1 14:11 acct/
-rw------- 1 uucp bin 0 Sep 1 14:08 aculog
-r--r--r-- 1 root root 350700 Sep 3 10:37 lastlog
drwxr-xr-x 2 adm adm 512 Sep 1 14:08 log/
-rw-r--r-- 1 root root 14619 Sep 2 16:11 messages
-rw-r--r-- 1 adm adm 8200 Sep 3 14:35 pacct
-rw-r--r-- 1 adm adm 920 Sep 3 10:47 pacct1
drwxr-xr-x 2 adm adm 512 Sep 1 14:08 passwd/
drwxrwxr-x 2 adm sys 512 Sep 1 14:11 sa/
drwxr-xr-x 2 root sys 512 Sep 1 14:36 sm.bin/
-rw-rw-rw- 1 root bin 0 Sep 1 14:08 spellhist
-rw------- 1 root root 420 Sep 3 14:17 sulog
-rw-r--r-- 1 root bin 4092 Sep 3 10:37 utmpx
-rw-r--r-- 1 root root 122 Sep 1 15:39 vold.log
-rw-r--r-- 1 adm adm 11904 Sep 3 10:47 wtmpx
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The following example shows that lpsched.1 uses two blocks.
$ cd /var/lp/logs
$ ls -s
total 2 0 lpsched 2 lpsched.1
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How to Find Large Files
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Change directory to the location you want to search.
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Display the size of files in blocks from largest to smallest.
$ ls -s | sort -nr | more
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sort -nr
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Sorts the list of files by block size from smallest to largest.
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Example--Finding Large Files
In the following example, lastlog and messages 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
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How to Find Files That Exceed a Given Size Limit
To locate and display the names of files that exceed a specified size, use the find command.
$ find directory -size +nnn
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directory
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Directory you want to search.
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-size +nnn
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Is a number of 512-byte blocks. Files that exceed the size indicated are listed.
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Example--Finding Files That Exceed a Given Size Limit
The following example shows how to find files with more 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
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Checking the Size of Directories
You can display the size of directories by using the du command and its options. Additionally, you can find the amount of disk space taken up by user accounts on local UFS file systems by using the quot command. For more information about these commands, see du(1M)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 ...]
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du
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Displays the size of each directory you specify, including each subdirectory beneath it.
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-a
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Displays the size of each file and subdirectory, and the total number of blocks contained in the specified directory.
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-s
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Displays only the total number of blocks contained in the specified directory.
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directory ...
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Specifies one or more directories you want to check.
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Examples--Displaying the Size of Directories, Subdirectories, and Files
The following example displays the total sizes of two directories and all the subdirectories they contain.
$ du -s /var/adm /var/spool/lp
130 /var/adm
40 /var/spool/lp
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The following example displays 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
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How to Display the User Allocation of Local UFS File Systems
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Become superuser.
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Display users, directories, or file systems, and the number of 1024-byte blocks used.
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-a
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Lists all users of each mounted UFS file system and the number of 1024-byte blocks used.
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filesystem
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Is a UFS file system. Users and the number of blocks used are displayed.
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Note -
The quot command works only on local UFS file systems.
Example--Displaying the User Allocation 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
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Finding and Removing Old and 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 these files, refer to Chapter 39, Managing System Crash Information.
How to List the Newest Files
List files, displaying the most recently created or changed files first, by using the ls -t command.
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-t
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Sorts listings by latest time stamp first.
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directory
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Directory you want to search.
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Example--Listing the Newest Files
The following example shows how to use ls -tl to locate the most recent 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
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How to Find and Remove Old or Inactive Files
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Become superuser.
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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
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directory
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Directory you want to check. Directories below this also will be checked.
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-atime +nnn
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Finds files that have not been accessed within the number of days you specify.
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-mtime +nnn
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Finds files that have not been modified within the number of days you specify.
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filename
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File containing the list of inactive files.
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Remove the inactive files that you listed in the previous step.
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filename
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File created in previous step which contains the list of inactive files.
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Example--Finding and Removing Old or Inactive Files
The following example locates regular files in /var/adm and its directories that have not been accessed in the last 60 days and saves the list of inactive files in /var/tmp/deadfiles. These files are then removed with the rm command.
# find /var/adm -type f -atime +60 -print > /var/tmp/deadfiles &
# more /var/tmp/deadfiles
/var/adm/log/asppp.log
/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`
#
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How to Clear Out Temporary Directories
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Become superuser.
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Change to the /var/tmp directory.
Caution - Be sure you are in the right directory before completing the following step. The next step deletes all files in the current directory.
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Delete the files and subdirectories in the current directory.
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Change to other directories containing unnecessary temporary or obsolete subdirectories and files, and delete them by repeating Step 3 above.
Example--Clearing Out Temporary Directories
The following example shows how to clear out the /var/tmp directory, and verifies that all files and subdirectories were removed.
# cd /var/tmp
# ls
deadfiles wxconAAAa0003r:0.0 wxconAAAa000NA:0.0
test_dir wxconAAAa0003u:0.0 wxconAAAa000cc:0.0
wxconAAAa000zs:0.0
# rm -r *
# ls
#
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How to Find and Delete core Files
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Become superuser.
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Change the directory to where you want to start the search.
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Find and remove any core files in this directory and its subdirectories.
# find . -name core -exec rm {} \;
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Example--Finding and Deleting core Files
The following example shows how to find and remove core files from the user account belonging to jones using the find command.
# cd /home/jones
# find . -name core -exec rm {} \;
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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.
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Become superuser.
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Change to the directory where crash dump files are stored.
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system
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System that created the crash dump files.
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Caution - Be sure you are in the right directory before completing the following step. The next step deletes all files in the current directory.
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Remove the crash dump files.
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Verify the crash dump files are removed.
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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