mkfs 매뉴얼
이름
mkfs - 리눅스 파일 시스템 만들기
사용법
mkfs [ -V ] [ -t 형태 ] [ fs-options ] 장치이름 [ 블럭 ]
설명
mkfs 명령은 한 장치(보통 한 하드디스크 파티션)를
리눅스 파
일 시스템으로만드는데 사용된다. 장치 이 름 은 /dev/hda1,
/dev/sdb2 이 런 식의 디스크 장치 이름이거나, /, /usr/,
/home 같은 파일시스템을 위한 마운트 경로가 사용된다. 블럭
인자는 그 파일 시스템을 위해 사용되는 블럭의 갯수이다.
성공적으로 끝나면, 0, 실패하면, 1을 리턴한다.
실질적으로, mkfs 명령은파일
시스템을 만드는데 각각 그 특정
파일 시스템을 만드는명령을 사용한다. 그 풀그림들의 이름 은
대 게 mkfs.파일시스템이름형식으로 되어 있다. 그
풀그림들은
먼저 /etc/fs 경로안에 있거나, 아니면, /sbin 경로안에 있 게
된 다. 특정 파일 시스템을 생성하는 풀그림에 대한보다 자세
한 사항은 각 파일 시스템을 만드는 각 풀그림들의 매뉴얼 페
이지를참조한다.
옵션
-V 정 보를 자세하게 보여준다. 여기에는
실행되는 특정
파일 시스템을 만드는 풀그림에 대한 정보도모두 포 함
된 다. 이 옵션이 한번 이상 사용되면 특정 파일 시스
템을 만드는데 사용될그 풀그림의 정보만 보여주고 실
질 적으로 실행은 되지 않는다. 이것은 실질적으로 검
사하는 것에만 유용하게 쓰인다.
-t 형태
만들어질 파일 시스템의 형태를 지정한다. 이 옵션 이
지정되지 않으면, /etc/fstab 파일에서 그 해당 파일시
스템을 찾고, 여기서도 못 찾으면, 기본적으
로 minix
파일 시스템을 사용한다.
fs-options
이것은 각 특정 파일 시스템을 만드는 풀그림에서 사용
되는 옵션을말한다. 대부분 같은 형식의 옵션이다.
-c 파일
시스템을 만들기 전에 먼저 불량 블럭 검사를 한
다.
-l 파일이름
filename 으로부터 불량 블럭 목록을 읽는다.
-v 작업 상태, 결과를 자세하게 보여준다.
fsck 매뉴얼
NAME
fsck - check and repair a Linux file system
SYNOPSIS
fsck [ -sAVRTNP ] [ -C [ fd ] ] [ -t fstype ] [filesys ... ] [--] [ fs-
specific-options ]
DESCRIPTION
fsck is used to check and optionally repair one or more Linux file sys-
tems. filesys can be a device name (e.g. /dev/hdc1, /dev/sdb2), a
mount point (e.g. /, /usr, /home), or an ext2 label or UUID specifier
(e.g. UUID=8868abf6-88c5-4a83-98b8-bfc24057f7bd or LABEL=root). Nor-
mally, the fsck program will try to handle filesystems on different
physical disk drives in parallel to reduce the total amount of time
needed to check all of the filesystems.
If no filesystems are specified on the command line, and the -A option
is not specified, fsck will default to checking filesystems in
/etc/fstab serially. This is equivalent to the -As options.
The exit code returned by fsck is the sum of the following conditions:
0 - No errors
1 - File system errors corrected
2 - System should be rebooted
4 - File system errors left uncorrected
8 - Operational error
16 - Usage or syntax error
32 - Fsck canceled by user request
128 - Shared library error
The exit code returned when multiple file systems are checked is the
bit-wise OR of the exit codes for each file system that is checked.
In actuality, fsck is simply a front-end for the various file system
checkers (fsck.fstype) available under Linux. The file system-specific
checker is searched for in /sbin first, then in /etc/fs and /etc, and
finally in the directories listed in the PATH environment variable.
Please see the file system-specific checker manual pages for further
details.
OPTIONS
-s Serialize fsck operations. This is a good idea if you are
checking multiple filesystems and the checkers are in an inter-
active mode. (Note: e2fsck(8) runs in an interactive mode by
default. To make e2fsck(8) run in a non-interactive mode, you
must either specify the -p or -a option, if you wish for errors
to be corrected automatically, or the -n option if you do not.)
-t fslist
Specifies the type(s) of file system to be checked. When the -A
flag is specified, only filesystems that match fslist are
checked. The fslist parameter is a comma-separated list of
filesystems and options specifiers. All of the filesystems in
this comma-separated list may be prefixed by a negation operator
'no' or '!', which requests that only those filesystems not
listed in fslist will be checked. If all of the filesystems in
fslist are not prefixed by a negation operator, then only those
filesystems listed in fslist will be checked.
Options specifiers may be included in the comma-separated
fslist. They must have the format opts=fs-option. If an
options specifier is present, then only filesystems which con-
tain fs-option in their mount options field of /etc/fstab will
be checked. If the options specifier is prefixed by a negation
operator, then only those filesystems that do not have fs-option
in their mount options field of /etc/fstab will be checked.
For example, if opts=ro appears in fslist, then only filesystems
listed in /etc/fstab with the ro option will be checked.
For compatibility with Mandrake distributions whose boot scripts
depend upon an unauthorized UI change to the fsck program, if a
filesystem type of loop is found in fslist, it is treated as if
opts=loop were specified as an argument to the -t option.
Normally, the filesystem type is deduced by searching for
filesys in the /etc/fstab file and using the corresponding
entry. If the type can not be deduced, and there is only a sin-
gle filesystem given as an argument to the -t option, fsck will
use the specified filesystem type. If this type is not avail-
able, then the default file system type (currently ext2) is
used.
-A Walk through the /etc/fstab file and try to check all file sys-
tems in one run. This option is typically used from the /etc/rc
system initialization file, instead of multiple commands for
checking a single file system.
The root filesystem will be checked first unless the -P option
is specified (see below). After that, filesystems will be
checked in the order specified by the fs_passno (the sixth)
field in the /etc/fstab file. Filesystems with a fs_passno
value of 0 are skipped and are not checked at all. Filesystems
with a fs_passno value of greater than zero will be checked in
order, with filesystems with the lowest fs_passno number being
checked first. If there are multiple filesystems with the same
pass number, fsck will attempt to check them in parallel,
although it will avoid running multiple filesystem checks on the
same physical disk.
Hence, a very common configuration in /etc/fstab files is to set
the root filesystem to have a fs_passno value of 1 and to set
all other filesystems to have a fs_passno value of 2. This will
allow fsck to automatically run filesystem checkers in parallel
if it is advantageous to do so. System administrators might
choose not to use this configuration if they need to avoid mul-
tiple filesystem checks running in parallel for some reason ---
for example, if the machine in question is short on memory so
that excessive paging is a concern.
-C [ fd ]
Display completion/progress bars for those filesystem checkers
(currently only for ext2 and ext3) which support them. Fsck
will manage the filesystem checkers so that only one of them
will display a progress bar at a time. GUI front-ends may spec-
ify a file descriptor fd, in which case the progress bar infor-
mation will be sent to that file descriptor.
-N Don't execute, just show what would be done.
-P When the -A flag is set, check the root filesystem in parallel
with the other filesystems. This is not the safest thing in the
world to do, since if the root filesystem is in doubt things
like the e2fsck(8) executable might be corrupted! This option
is mainly provided for those sysadmins who don't want to repar-
tition the root filesystem to be small and compact (which is
really the right solution).
-R When checking all file systems with the -A flag, skip the root
file system (in case it's already mounted read-write).
-T Don't show the title on startup.
-V Produce verbose output, including all file system-specific com-
mands that are executed.
fs-specific-options
Options which are not understood by fsck are passed to the
filesystem-specific checker. These arguments must not take
arguments, as there is no way for fsck to be able to properly
guess which arguments take options and which don't.
Options and arguments which follow the -- are treated as file
system-specific options to be passed to the file system-specific
checker.
Please note that fsck is not designed to pass arbitrarily com-
plicated options to filesystem-specific checkers. If you're
doing something complicated, please just execute the filesystem-
specific checker directly. If you pass fsck some horribly com-
plicated option and arguments, and it doesn't do what you
expect, don't bother reporting it as a bug. You're almost cer-
tainly doing something that you shouldn't be doing with fsck.
Options to different filesystem-specific fsck's are not standardized.
If in doubt, please consult the man pages of the filesystem-specific
checker. Although not guaranteed, the following options are supported
by most file system checkers:
-a Automatically repair the file system without any questions (use
this option with caution). Note that e2fsck(8) supports -a for
backwards compatibility only. This option is mapped to e2fsck's
-p option which is safe to use, unlike the -a option that some
file system checkers support.
-n For some filesystem-specific checkers, the -n option will cause
the fs-specific fsck to avoid attempting to repair any problems,
but simply report such problems to stdout. This is however not
true for all filesystem-specific checkers. In particular,
fsck.reiserfs(8) will not report any corruption if given this
option. fsck.minix(8) does not support the -n option at all.
-r Interactively repair the filesystem (ask for confirmations).
Note: It is generally a bad idea to use this option if multiple
fsck's are being run in parallel. Also note that this is
e2fsck's default behavior; it supports this option for backwards
compatibility reasons only.
-y For some filesystem-specific checkers, the -y option will cause
the fs-specific fsck to always attempt to fix any detected
filesystem corruption automatically. Sometimes an expert may be
able to do better driving the fsck manually. Note that not all
filesystem-specific checkers implement this option. In particu-
lar fsck.minix(8) and fsck.cramfs(8) does not support the -y
option as of this writing.
AUTHOR
Theodore Ts'o (tytso@mit.edu)
FILES
/etc/fstab.
ENVIRONMENT VARIABLES
The fsck program's behavior is affected by the following environment
variables:
FSCK_FORCE_ALL_PARALLEL
If this environment variable is set, fsck will attempt to run
all of the specified filesystems in parallel, regardless of
whether the filesystems appear to be on the same device. (This
is useful for RAID systems or high-end storage systems such as
those sold by companies such as IBM or EMC.)
FSCK_MAX_INST
This environment variable will limit the maximum number of file
system checkers that can be running at one time. This allows
configurations which have a large number of disks to avoid fsck
starting too many file system checkers at once, which might
overload CPU and memory resources available on the system. If
this value is zero, then an unlimited number of processes can be
spawned. This is currently the default, but future versions of
fsck may attempt to automatically determine how many file system
checks can be run based on gathering accounting data from the
operating system.
PATH The PATH environment variable is used to find file system check-
ers. A set of system directories are searched first: /sbin,
/sbin/fs.d, /sbin/fs, /etc/fs, and /etc. Then the set of direc-
tories found in the PATH environment are searched.
FSTAB_FILE
This environment variable allows the system administrator to
override the standard location of the /etc/fstab file. It is
also useful for developers who are testing fsck.
SEE ALSO
fstab(5), mkfs(8), fsck.ext2(8) or fsck.ext3(8) or e2fsck(8), cramf-
sck(8), fsck.minix(8), fsck.msdos(8), fsck.jfs(8), fsck.nfs(8),
fsck.vfat(8), fsck.xfs(8), fsck.xiafs(8), reiserfsck(8).
mkswap 메뉴얼
NAME
mkswap - set up a Linux swap area
SYNOPSIS
mkswap [-c] [-vN] [-f] [-p PSZ] [-L label] device [size]
DESCRIPTION
mkswap sets up a Linux swap area on a device or in a file.
(After creating the swap area, you need the swapon command to start
using it. Usually swap areas are listed in /etc/fstab so that they can
be taken into use at boot time by a swapon -a command in some boot
script.)
The device argument will usually be a disk partition (something like
/dev/hda4 or /dev/sdb7) but can also be a file. The Linux kernel does
not look at partition Id's, but many installation scripts will assume
that partitions of hex type 82 (LINUX_SWAP) are meant to be swap parti-
tions. (Warning: Solaris also uses this type. Be careful not to kill
your Solaris partitions.)
The size parameter is superfluous but retained for backwards compati-
bility. (It specifies the desired size of the swap area in 1024-byte
blocks. mkswap will use the entire partition or file if it is omitted.
Specifying it is unwise - a typo may destroy your disk.)
The PSZ parameter specifies the page size to use. It is almost always
unnecessary (even unwise) to specify it, but certain old libc versions
lie about the page size, so it is possible that mkswap gets it wrong.
The symptom is that a subsequent swapon fails because no swap signature
is found. Typical values for PSZ are 4096 or 8192.
Linux knows about two styles of swap areas, old style and new style.
The last 10 bytes of the first page of the swap area distinguishes
them: old style has 'SWAP_SPACE', new style has 'SWAPSPACE2' as signa-
ture.
In the old style, the rest of this first page was a bit map, with a 1
bit for each usable page of the swap area. Since the first page holds
this bit map, the first bit is 0. Also, the last 10 bytes hold the
signature. So, if the page size is S, an old style swap area can
describe at most 8*(S-10)-1 pages used for swapping. With S=4096 (as
on i386), the useful area is at most 133890048 bytes (almost 128 MiB),
and the rest is wasted. On an alpha and sparc64, with S=8192, the use-
ful area is at most 535560992 bytes (almost 512 MiB).
The old setup wastes most of this bitmap page, because zero bits denote
bad blocks or blocks past the end of the swap space, and a simple inte-
ger suffices to indicate the size of the swap space, while the bad
blocks, if any, can simply be listed. Nobody wants to use a swap space
with hundreds of bad blocks. (I would not even use a swap space with 1
bad block.) In the new style swap area this is precisely what is done.
The maximum useful size of a swap area depends on the architecture and
the kernel version. It is roughly 2GiB on i386, PPC, m68k, ARM, 1GiB
on sparc, 512MiB on mips, 128GiB on alpha and 3TiB on sparc64. For ker-
nels after 2.3.3 there is no such limitation.
Note that before 2.1.117 the kernel allocated one byte for each page,
while it now allocates two bytes, so that taking a swap area of 2 GiB
in use might require 2 MiB of kernel memory.
Presently, Linux allows 32 swap areas (this was 8 before Linux 2.4.10).
The areas in use can be seen in the file /proc/swaps (since 2.1.25).
mkswap refuses areas smaller than 10 pages.
If you don't know the page size that your machine uses, you may be able
to look it up with "cat /proc/cpuinfo" (or you may not - the contents
of this file depend on architecture and kernel version).
To setup a swap file, it is necessary to create that file before ini-
tializing it with mkswap , e.g. using a command like
# dd if=/dev/zero of=swapfile bs=1024 count=65536
Note that a swap file must not contain any holes (so, using cp(1) to
create the file is not acceptable).
OPTIONS
-c Check the device (if it is a block device) for bad blocks before
creating the swap area. If any are found, the count is printed.
-f Force - go ahead even if the command is stupid. This allows the
creation of a swap area larger than the file or partition it
resides on. On SPARC, force creation of the swap area. Without
this option mkswap will refuse to create a v0 swap on a device
with a valid SPARC superblock, as that probably means one is
going to erase the partition table.
-p PSZ Specify the page size to use.
-L label
Specify a label, to allow swapon by label. (Only for new style
swap areas.)
-v0 Create an old style swap area.
-v1 Create a new style swap area.
If no -v option is given, mkswap will default to new style, but use old
style if the current kernel is older than 2.1.117 (and also if
PAGE_SIZE is less than 2048). The new style header does not touch the
first block, so may be preferable, in case you have a boot loader or
disk label there. If you need to use both 2.0 and 2.2 kernels, use the
-v0 option when creating the swapspace.
SEE ALSO
fdisk(8), swapon(8)