[Linux] 파일 시스템 관리 명령어 정리

[Linux] 파일 시스템 관리 명령어 정리

분류	명령어
권한	chmod	chown	chgrp	umask
파일 시스템	mount	umount	fdisk	mkfs	mke2fs	fsck	e2fsck	df
	du	dd	stat	blkid
스왑	mkswap	swapon	swapoff	free
Disk Quota	quotacheck	edquota	quotaon	quotaoff	repquota	quota
파일 링크	ln

 

chmod

• 파일이나 디렉터리에 접근할 수 있는 허가권(Permission)을 설정하는 명령어

$ chmod --help

Usage: chmod [OPTION]... MODE[,MODE]... FILE...
  or:  chmod [OPTION]... OCTAL-MODE FILE...
  or:  chmod [OPTION]... --reference=RFILE FILE...
Change the mode of each FILE to MODE.
With --reference, change the mode of each FILE to that of RFILE.

  -c, --changes          like verbose but report only when a change is made
  -f, --silent, --quiet  suppress most error messages
  -v, --verbose          output a diagnostic for every file processed
      --no-preserve-root  do not treat '/' specially (the default)
      --preserve-root    fail to operate recursively on '/'
      --reference=RFILE  use RFILE's mode instead of MODE values
  -R, --recursive        change files and directories recursively
      --help     display this help and exit
      --version  output version information and exit

Each MODE is of the form '[ugoa]*([-+=]([rwxXst]*|[ugo]))+|[-+=][0-7]+'.

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'chmod invocation'

 

chown

• 파일이나 디렉터리의 소유권 및 그룹 소유권을 변경하는 명령어

$ chown --help

Usage: chown [OPTION]... [OWNER][:[GROUP]] FILE...
  or:  chown [OPTION]... --reference=RFILE FILE...
Change the owner and/or group of each FILE to OWNER and/or GROUP.
With --reference, change the owner and group of each FILE to those of RFILE.

  -c, --changes          like verbose but report only when a change is made
  -f, --silent, --quiet  suppress most error messages
  -v, --verbose          output a diagnostic for every file processed
      --dereference      affect the referent of each symbolic link (this is
                         the default), rather than the symbolic link itself
  -h, --no-dereference   affect symbolic links instead of any referenced file
                         (useful only on systems that can change the
                         ownership of a symlink)
      --from=CURRENT_OWNER:CURRENT_GROUP
                         change the owner and/or group of each file only if
                         its current owner and/or group match those specified
                         here.  Either may be omitted, in which case a match
                         is not required for the omitted attribute
      --no-preserve-root  do not treat '/' specially (the default)
      --preserve-root    fail to operate recursively on '/'
      --reference=RFILE  use RFILE's owner and group rather than
                         specifying OWNER:GROUP values
  -R, --recursive        operate on files and directories recursively

The following options modify how a hierarchy is traversed when the -R
option is also specified.  If more than one is specified, only the final
one takes effect.

  -H                     if a command line argument is a symbolic link
                         to a directory, traverse it
  -L                     traverse every symbolic link to a directory
                         encountered
  -P                     do not traverse any symbolic links (default)

      --help     display this help and exit
      --version  output version information and exit

Owner is unchanged if missing.  Group is unchanged if missing, but changed
to login group if implied by a ':' following a symbolic OWNER.
OWNER and GROUP may be numeric as well as symbolic.

Examples:
  chown root /u        Change the owner of /u to "root".
  chown root:staff /u  Likewise, but also change its group to "staff".
  chown -hR root /u    Change the owner of /u and subfiles to "root".

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'chown invocation'

 

chgrp

• 파일이나 디레터리의 소유 그룹을 바꾸는 명령어

$ chgrp --help

Usage: chgrp [OPTION]... GROUP FILE...
  or:  chgrp [OPTION]... --reference=RFILE FILE...
Change the group of each FILE to GROUP.
With --reference, change the group of each FILE to that of RFILE.

  -c, --changes          like verbose but report only when a change is made
  -f, --silent, --quiet  suppress most error messages
  -v, --verbose          output a diagnostic for every file processed
      --dereference      affect the referent of each symbolic link (this is
                         the default), rather than the symbolic link itself
  -h, --no-dereference   affect symbolic links instead of any referenced file
                         (useful only on systems that can change the
                         ownership of a symlink)
      --no-preserve-root  do not treat '/' specially (the default)
      --preserve-root    fail to operate recursively on '/'
      --reference=RFILE  use RFILE's group rather than specifying a
                         GROUP value
  -R, --recursive        operate on files and directories recursively

The following options modify how a hierarchy is traversed when the -R
option is also specified.  If more than one is specified, only the final
one takes effect.

  -H                     if a command line argument is a symbolic link
                         to a directory, traverse it
  -L                     traverse every symbolic link to a directory
                         encountered
  -P                     do not traverse any symbolic links (default)

      --help     display this help and exit
      --version  output version information and exit

Examples:
  chgrp staff /u      Change the group of /u to "staff".
  chgrp -hR staff /u  Change the group of /u and subfiles to "staff".

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'chgrp invocation'

 

umask

• 파일이나 디렉터리 생성 시 부여되는 기본 허가권 값을 지정하는 명령어
• 다음의 값에서 설정한 umask 값을 뺀 값을 기본 허가권으로 지정
  • 파일 : 666
  • 디렉터리 : 777

$ umask --help

umask: usage: umask [-p] [-S] [mode]

 

mount

• 보조기억장치나 파일 시스템이 다른 디스크의 / 의 하위 디렉터리로 연결하여 사용 가능하게 해주는 명령어
• 특정한 옵션 없이 사용할 경우, 현재 마운트된 장치나 디스크를 확인할 수 있음.

$ mount --help

Usage:
 mount [-lhV]
 mount -a [options]
 mount [options] [--source] <source> | [--target] <directory>
 mount [options] <source> <directory>
 mount <operation> <mountpoint> [<target>]

Options:
 -a, --all               mount all filesystems mentioned in fstab
 -c, --no-canonicalize   don't canonicalize paths
 -f, --fake              dry run; skip the mount(2) syscall
 -F, --fork              fork off for each device (use with -a)
 -T, --fstab <path>      alternative file to /etc/fstab
 -h, --help              display this help text and exit
 -i, --internal-only     don't call the mount.<type> helpers
 -l, --show-labels       lists all mounts with LABELs
 -n, --no-mtab           don't write to /etc/mtab
 -o, --options <list>    comma-separated list of mount options
 -O, --test-opts <list>  limit the set of filesystems (use with -a)
 -r, --read-only         mount the filesystem read-only (same as -o ro)
 -t, --types <list>      limit the set of filesystem types
     --source <src>      explicitly specifies source (path, label, uuid)
     --target <target>   explicitly specifies mountpoint
 -v, --verbose           say what is being done
 -V, --version           display version information and exit
 -w, --rw, --read-write  mount the filesystem read-write (default)

 -h, --help     display this help and exit
 -V, --version  output version information and exit

Source:
 -L, --label <label>     synonym for LABEL=<label>
 -U, --uuid <uuid>       synonym for UUID=<uuid>
 LABEL=<label>           specifies device by filesystem label
 UUID=<uuid>             specifies device by filesystem UUID
 PARTLABEL=<label>       specifies device by partition label
 PARTUUID=<uuid>         specifies device by partition UUID
 <device>                specifies device by path
 <directory>             mountpoint for bind mounts (see --bind/rbind)
 <file>                  regular file for loopdev setup

Operations:
 -B, --bind              mount a subtree somewhere else (same as -o bind)
 -M, --move              move a subtree to some other place
 -R, --rbind             mount a subtree and all submounts somewhere else
 --make-shared           mark a subtree as shared
 --make-slave            mark a subtree as slave
 --make-private          mark a subtree as private
 --make-unbindable       mark a subtree as unbindable
 --make-rshared          recursively mark a whole subtree as shared
 --make-rslave           recursively mark a whole subtree as slave
 --make-rprivate         recursively mark a whole subtree as private
 --make-runbindable      recursively mark a whole subtree as unbindable

For more details see mount(8).

 

umount

• 마운트된 파일 시스템을 해제시켜주는 명령어

$ umount --help

Usage:
 umount [-hV]
 umount -a [options]
 umount [options] <source> | <directory>

Options:
 -a, --all               unmount all filesystems
 -A, --all-targets       unmount all mountpoins for the given device
                         in the current namespace
 -c, --no-canonicalize   don't canonicalize paths
 -d, --detach-loop       if mounted loop device, also free this loop device
     --fake              dry run; skip the umount(2) syscall
 -f, --force             force unmount (in case of an unreachable NFS system)
 -i, --internal-only     don't call the umount.<type> helpers
 -n, --no-mtab           don't write to /etc/mtab
 -l, --lazy              detach the filesystem now, and cleanup all later
 -O, --test-opts <list>  limit the set of filesystems (use with -a)
 -R, --recursive         recursively unmount a target with all its children
 -r, --read-only         In case unmounting fails, try to remount read-only
 -t, --types <list>      limit the set of filesystem types
 -v, --verbose           say what is being done

 -h, --help     display this help and exit
 -V, --version  output version information and exit

For more details see umount(8).

 

fdisk

• 디스크 파티션을 확인하고 추가/삭제하는 명령어

$ fdisk --help

Usage:
 fdisk [options] <disk>    change partition table
 fdisk [options] -l <disk> list partition table(s)
 fdisk -s <partition>      give partition size(s) in blocks

Options:
 -b <size>             sector size (512, 1024, 2048 or 4096)
 -c[=<mode>]           compatible mode: 'dos' or 'nondos' (default)
 -h                    print this help text
 -u[=<unit>]           display units: 'cylinders' or 'sectors' (default)
 -v                    print program version
 -C <number>           specify the number of cylinders
 -H <number>           specify the number of heads
 -S <number>           specify the number of sectors per track

 

mkfs

• 새로운 파일 시스템을 만드는 명령 (make file system)
• root 만 사용 가능
• 파일 시스템 유형을 지정하지 않으면 ext2로 생성됨.

$ mkfs --help

Usage:
 mkfs [options] [-t <type>] [fs-options] <device> [<size>]

Options:
 -t, --type=<type>  filesystem type; when unspecified, ext2 is used
     fs-options     parameters for the real filesystem builder
     <device>       path to the device to be used
     <size>         number of blocks to be used on the device
 -V, --verbose      explain what is being done;
                      specifying -V more than once will cause a dry-run
 -V, --version      display version information and exit;
                      -V as --version must be the only option
 -h, --help         display this help text and exit

For more information see mkfs(8).

 

mke2fs

• ext2, ext3, ext4 파일 시스템을 만드는 명령
• 최근 리눅스 배포판에서 mkfs 명령 실행 시 실제 사용되는 명령어
• 파일 시스템의 유형을 지정하지 않으면 ext2로 생성됨.

$ mke2fs --help

Usage: mke2fs [-c|-l filename] [-b block-size] [-C cluster-size]
	[-i bytes-per-inode] [-I inode-size] [-J journal-options]
	[-G flex-group-size] [-N number-of-inodes]
	[-m reserved-blocks-percentage] [-o creator-os]
	[-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
	[-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
	[-t fs-type] [-T usage-type ] [-U UUID] [-jnqvDFKSV] device [blocks-count]

 

fsck

• ext 계열 리눅스 파일 시스템을 검사하고 수리하는 명령어

$ fsck --help

• -a : 명령 수행에 대한 확인 질문 없이 무조건 수행
• -r
  • 명령 수행에 대한 확인 질문을 함.
  • 여러 개의 fsck가 병렬 모드 형태로 작동하고 있을 때 유용
• -A : /etc/fstab에 정의되어 있는 모든 파일 시스템을 체크
• -P : -A 옵션을 사용할 때, 루트 파일 시스템을 다른 파일 시스템과 병렬로 함께 체크
• -R : -A 옵션을 사용할 때, 루트 파일 시스템은 체크하지 않고 건너띔.
• -N : 실행을 하지 않고 단지 어떤 것이 실행되어지는지만 보여줌.
• -T : 검사를 시작할 때 제목을 보여주지 않음.
• -s
  • fsck 동작을 시리얼화 함.
  • 대화형 모드에서 여러 파일 시스템을 점검할 때 유용함.
• -V : 실행되는 각 파일 시스템용 명령을 포함해 자세한 출력을 수행
• -v : 버전 정보를 보여줌.
• -t fs_type
  • 점검할 파일 시스템의 유형 지정
  • 파일 시스템 앞에 no를 붙이면 지정한 파일 시스템을 제외한 나머지를 검사
  • -A 옵션이 설정되어 있는 경우, /etc/fstab에서 파일 시스템 유형이 맞는 것만 검사

 

e2fsck

• 리눅스 파일 시스템인 ext2, ext3, ext4를 검사하고 수리하는 명령어
• 현재 리눅스 배포판에서 fsck 명령 실행 시 실제 사용되는 명령어

$ e2fsck --help

Usage: e2fsck [-panyrcdfvtDFV] [-b superblock] [-B blocksize]
		[-I inode_buffer_blocks] [-P process_inode_size]
		[-l|-L bad_blocks_file] [-C fd] [-j external_journal]
		[-E extended-options] device

Emergency help:
 -p                   Automatic repair (no questions)
 -n                   Make no changes to the filesystem
 -y                   Assume "yes" to all questions
 -c                   Check for bad blocks and add them to the badblock list
 -f                   Force checking even if filesystem is marked clean
 -v                   Be verbose
 -b superblock        Use alternative superblock
 -B blocksize         Force blocksize when looking for superblock
 -j external_journal  Set location of the external journal
 -l bad_blocks_file   Add to badblocks list
 -L bad_blocks_file   Set badblocks list

 

fsck.ext2, fsck.ext3, fsck.ext4, fsck.xfs

• 파일 시스템 검사 명령어

$ fsck.xfs /dev/sdb1

 

df

• 현재 마운트된 디스크의 크기, 사용량, 남아있는 용량 등에 대한 정보 출력

$ df --help

Usage: df [OPTION]... [FILE]...
Show information about the file system on which each FILE resides,
or all file systems by default.

Mandatory arguments to long options are mandatory for short options too.
  -a, --all             include pseudo, duplicate, inaccessible file systems
  -B, --block-size=SIZE  scale sizes by SIZE before printing them; e.g.,
                           '-BM' prints sizes in units of 1,048,576 bytes;
                           see SIZE format below
      --direct          show statistics for a file instead of mount point
      --total           produce a grand total
  -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)
  -H, --si              likewise, but use powers of 1000 not 1024
  -i, --inodes          list inode information instead of block usage
  -k                    like --block-size=1K
  -l, --local           limit listing to local file systems
      --no-sync         do not invoke sync before getting usage info (default)
      --output[=FIELD_LIST]  use the output format defined by FIELD_LIST,
                               or print all fields if FIELD_LIST is omitted.
  -P, --portability     use the POSIX output format
      --sync            invoke sync before getting usage info
  -t, --type=TYPE       limit listing to file systems of type TYPE
  -T, --print-type      print file system type
  -x, --exclude-type=TYPE   limit listing to file systems not of type TYPE
  -v                    (ignored)
      --help     display this help and exit
      --version  output version information and exit

Display values are in units of the first available SIZE from --block-size,
and the DF_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.
Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).

SIZE is an integer and optional unit (example: 10M is 10*1024*1024).  Units
are K, M, G, T, P, E, Z, Y (powers of 1024) or KB, MB, ... (powers of 1000).

FIELD_LIST is a comma-separated list of columns to be included.  Valid
field names are: 'source', 'fstype', 'itotal', 'iused', 'iavail', 'ipcent',
'size', 'used', 'avail', 'pcent', 'file' and 'target' (see info page).

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'df invocation'

 

du

• 파일이나 디렉터리들이 디스크에서 차지하고 있는 크기 출력

$ du --help

Usage: du [OPTION]... [FILE]...
  or:  du [OPTION]... --files0-from=F
Summarize disk usage of each FILE, recursively for directories.

Mandatory arguments to long options are mandatory for short options too.
  -0, --null            end each output line with 0 byte rather than newline
  -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  scale sizes by SIZE before printing them; e.g.,
                           '-BM' prints sizes in units of 1,048,576 bytes;
                           see SIZE format below
  -b, --bytes           equivalent to '--apparent-size --block-size=1'
  -c, --total           produce a grand total
  -D, --dereference-args  dereference only symlinks that are listed on the
                          command line
  -d, --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
      --files0-from=F   summarize disk usage of the
                          NUL-terminated file names specified in file F;
                          if F is -, then read names from standard input
  -H                    equivalent to --dereference-args (-D)
  -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)
      --inodes          list inode usage information instead of block usage
  -k                    like --block-size=1K
  -L, --dereference     dereference all symbolic links
  -l, --count-links     count sizes many times if hard linked
  -m                    like --block-size=1M
  -P, --no-dereference  don't follow any symbolic links (this is the default)
  -S, --separate-dirs   for directories do not include size of subdirectories
      --si              like -h, but use powers of 1000 not 1024
  -s, --summarize       display only a total for each argument
  -t, --threshold=SIZE  exclude entries smaller than SIZE if positive,
                          or entries greater than SIZE if negative
      --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, which can be:
                            full-iso, long-iso, iso, or +FORMAT;
                            FORMAT is interpreted like in 'date'
  -X, --exclude-from=FILE  exclude files that match any pattern in FILE
      --exclude=PATTERN    exclude files that match PATTERN
  -x, --one-file-system    skip directories on different file systems
      --help     display this help and exit
      --version  output version information and exit

Display values are in units of the first available SIZE from --block-size,
and the DU_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.
Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).

SIZE is an integer and optional unit (example: 10M is 10*1024*1024).  Units
are K, M, G, T, P, E, Z, Y (powers of 1024) or KB, MB, ... (powers of 1000).

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'du invocation'

 

dd

• 디스크 이미지 형태로 백업하거나 파일의 포맷(형식)을 바꾸는 명령
• 다음의 경우에도 쓰임.
  • 텍스트 파일의 대소문자 변환
  • 부팅 디스크 제작
  • 스왑 파일 생성
  • 디바이스 초기화

$ dd --help

Usage: dd [OPERAND]...
  or:  dd OPTION
Copy a file, converting and formatting according to the operands.

  bs=BYTES        read and write up to BYTES bytes at a time
  cbs=BYTES       convert BYTES bytes at a time
  conv=CONVS      convert the file as per the comma separated symbol list
  count=N         copy only N input blocks
  ibs=BYTES       read up to BYTES bytes at a time (default: 512)
  if=FILE         read from FILE instead of stdin
  iflag=FLAGS     read as per the comma separated symbol list
  obs=BYTES       write BYTES bytes at a time (default: 512)
  of=FILE         write to FILE instead of stdout
  oflag=FLAGS     write as per the comma separated symbol list
  seek=N          skip N obs-sized blocks at start of output
  skip=N          skip N ibs-sized blocks at start of input
  status=LEVEL    The LEVEL of information to print to stderr;
                  'none' suppresses everything but error messages,
                  'noxfer' suppresses the final transfer statistics,
                  'progress' shows periodic transfer statistics

N and BYTES may be followed by the following multiplicative suffixes:
c =1, w =2, b =512, kB =1000, K =1024, MB =1000*1000, M =1024*1024, xM =M
GB =1000*1000*1000, G =1024*1024*1024, and so on for T, P, E, Z, Y.

Each CONV symbol may be:

  ascii     from EBCDIC to ASCII
  ebcdic    from ASCII to EBCDIC
  ibm       from ASCII to alternate EBCDIC
  block     pad newline-terminated records with spaces to cbs-size
  unblock   replace trailing spaces in cbs-size records with newline
  lcase     change upper case to lower case
  ucase     change lower case to upper case
  sparse    try to seek rather than write the output for NUL input blocks
  swab      swap every pair of input bytes
  sync      pad every input block with NULs to ibs-size; when used
            with block or unblock, pad with spaces rather than NULs
  excl      fail if the output file already exists
  nocreat   do not create the output file
  notrunc   do not truncate the output file
  noerror   continue after read errors
  fdatasync  physically write output file data before finishing
  fsync     likewise, but also write metadata

Each FLAG symbol may be:

  append    append mode (makes sense only for output; conv=notrunc suggested)
  direct    use direct I/O for data
  directory  fail unless a directory
  dsync     use synchronized I/O for data
  sync      likewise, but also for metadata
  fullblock  accumulate full blocks of input (iflag only)
  nonblock  use non-blocking I/O
  noatime   do not update access time
  nocache   discard cached data
  noctty    do not assign controlling terminal from file
  nofollow  do not follow symlinks
  count_bytes  treat 'count=N' as a byte count (iflag only)
  skip_bytes  treat 'skip=N' as a byte count (iflag only)
  seek_bytes  treat 'seek=N' as a byte count (oflag only)

Sending a USR1 signal to a running 'dd' process makes it
print I/O statistics to standard error and then resume copying.

  $ dd if=/dev/zero of=/dev/null& pid=$!
  $ kill -USR1 $pid; sleep 1; kill $pid
  18335302+0 records in
  18335302+0 records out
  9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s

Options are:

      --help     display this help and exit
      --version  output version information and exit

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'dd invocation

 

stat

• 파일 또는 파일 시스템 관련 정보를 출력하는 명령

$ stat --help

Usage: stat [OPTION]... FILE...
Display file or file system status.

Mandatory arguments to long options are mandatory for short options too.
  -L, --dereference     follow links
  -f, --file-system     display file system status instead of file status
  -c  --format=FORMAT   use the specified FORMAT instead of the default;
                          output a newline after each use of FORMAT
      --printf=FORMAT   like --format, but interpret backslash escapes,
                          and do not output a mandatory trailing newline;
                          if you want a newline, include \n in FORMAT
  -t, --terse           print the information in terse form
      --help     display this help and exit
      --version  output version information and exit

The valid format sequences for files (without --file-system):

  %a   access rights in octal
  %A   access rights in human readable form
  %b   number of blocks allocated (see %B)
  %B   the size in bytes of each block reported by %b
  %C   SELinux security context string
  %d   device number in decimal
  %D   device number in hex
  %f   raw mode in hex
  %F   file type
  %g   group ID of owner
  %G   group name of owner
  %h   number of hard links
  %i   inode number
  %m   mount point
  %n   file name
  %N   quoted file name with dereference if symbolic link
  %o   optimal I/O transfer size hint
  %s   total size, in bytes
  %t   major device type in hex, for character/block device special files
  %T   minor device type in hex, for character/block device special files
  %u   user ID of owner
  %U   user name of owner
  %w   time of file birth, human-readable; - if unknown
  %W   time of file birth, seconds since Epoch; 0 if unknown
  %x   time of last access, human-readable
  %X   time of last access, seconds since Epoch
  %y   time of last modification, human-readable
  %Y   time of last modification, seconds since Epoch
  %z   time of last change, human-readable
  %Z   time of last change, seconds since Epoch

Valid format sequences for file systems:

  %a   free blocks available to non-superuser
  %b   total data blocks in file system
  %c   total file nodes in file system
  %d   free file nodes in file system
  %f   free blocks in file system
  %i   file system ID in hex
  %l   maximum length of filenames
  %n   file name
  %s   block size (for faster transfers)
  %S   fundamental block size (for block counts)
  %t   file system type in hex
  %T   file system type in human readable form

NOTE: your shell may have its own version of stat, which usually supersedes
the version described here.  Please refer to your shell's documentation
for details about the options it supports.

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'stat invocation'

 

mkswap

• 스왑 파티션이나 스왑 파일을 생성하는 명령어

$ mkswap --help

Usage:
 mkswap [options] device [size]

Options:
 -c, --check               check bad blocks before creating the swap area
 -f, --force               allow swap size area be larger than device
 -p, --pagesize SIZE       specify page size in bytes
 -L, --label LABEL         specify label
 -v, --swapversion NUM     specify swap-space version number
 -U, --uuid UUID           specify the uuid to use
 -V, --version             output version information and exit
 -h, --help                display this help and exit

 

swapon

• 스왑 파티션이나 스왑 파일을 활성화 시키는 명령
• 스왑의 상태 확인도 가능

$ swapon --help

Usage:
 swapon [options] [<spec>]

Options:
 -a, --all                enable all swaps from /etc/fstab
 -d, --discard[=<policy>] enable swap discards, if supported by device
 -e, --ifexists           silently skip devices that do not exist
 -f, --fixpgsz            reinitialize the swap space if necessary
 -p, --priority <prio>    specify the priority of the swap device
 -s, --summary            display summary about used swap devices
     --show[=<columns>]   display summary in definable table
     --noheadings         don't print headings, use with --show
     --raw                use the raw output format, use with --show
     --bytes              display swap size in bytes in --show output
 -v, --verbose            verbose mode

 -h, --help     display this help and exit
 -V, --version  output version information and exit

The <spec> parameter:
 -L <label>             synonym for LABEL=<label>
 -U <uuid>              synonym for UUID=<uuid>
 LABEL=<label>          specifies device by swap area label
 UUID=<uuid>            specifies device by swap area UUID
 PARTLABEL=<label>      specifies device by partition label
 PARTUUID=<uuid>        specifies device by partition UUID
 <device>               name of device to be used
 <file>                 name of file to be used

Available discard policy types (for --discard):
 once	  : only single-time area discards are issued. (swapon)
 pages	  : discard freed pages before they are reused.
 * if no policy is selected both discard types are enabled. (default)

Available columns (for --show):
 NAME  device file or partition path
 TYPE  type of the device
 SIZE  size of the swap area
 USED  bytes in use
 PRIO  swap priority

For more details see swapon(8).

 

swapoff

• 활성화된 스왑 파티션이나 스왑 파일을 중지시킴.

$ swapoff --help

Usage:
 swapoff [options] [<spec>]

Options:
 -a, --all              disable all swaps from /proc/swaps
 -v, --verbose          verbose mode

 -h, --help     display this help and exit
 -V, --version  output version information and exit

The <spec> parameter:
 -L <label>             LABEL of device to be used
 -U <uuid>              UUID of device to be used
 LABEL=<label>          LABEL of device to be used
 UUID=<uuid>            UUID of device to be used
 <device>               name of device to be used
 <file>                 name of file to be used

For more details see swapoff(8).

 

free

• 현재 사용 중인 메모리의 상태를 출력해주는 명령어

$ free --help

Usage:
 free [options]

Options:
 -b, --bytes         show output in bytes
 -k, --kilo          show output in kilobytes
 -m, --mega          show output in megabytes
 -g, --giga          show output in gigabytes
     --tera          show output in terabytes
     --peta          show output in petabytes
 -h, --human         show human-readable output
     --si            use powers of 1000 not 1024
 -l, --lohi          show detailed low and high memory statistics
 -t, --total         show total for RAM + swap
 -s N, --seconds N   repeat printing every N seconds
 -c N, --count N     repeat printing N times, then exit
 -w, --wide          wide output

     --help     display this help and exit
 -V, --version  output version information and exit

For more details see free(1).