MOUNT(8) MOUNT(8) mount - mount [-h|-V] mount [-l] [-t __] mount -a [-F] [-fnrsvw] [-t fstype] [-O optlist] mount [-fnrsvw] [-o ] |_ mount [-fnrsvw] [-o options] [-t fstype] device mountpoint mount --bind|--rbind|--move _ _ mount --make-[r]{shared|slave|private|unbindable} mountpoint , Unix, , , /. . mount , , . , umount(8) '. , , . mount : mount -t , ( >) _>. -t _ '. mount . root , . . " " . ( ) , , _>. , : mount / mount ( , ) /etc/fstab. --target --source, . : mount --target /- , (, ) . mount . . --all: ( . --all ). . , , findmnt(8). , <>. ( _>): mount [-l] [-t ] -l . . . ( ), /dev/sda1, . , NFS, knuth.cwi.nl:/dir. ; , . , UUID LABEL. (): LABEL= , . . -L. UUID=uuid . UUID , . . -U. , mount UUID . UUID fstab(5) . UUID . PARTLABEL= . mkfs mkswap. , , GUID Partition Tables (GPT). PARTUUID=uuid . mkfs mkswap. , , GUID Partition Tables (GPT). ID= , udevd. WWN ( ) . . ls /dev/disk/by-id, udevd . , udev, udev . lsblk --fs , UUID . blkid -p <> . ', UUID , , . , UUID , lsblk -o +UUID,PARTUUID. - ( UUID=uuid), udev /dev/disk/by-{label,uuid,id,partuuid,partlabel} /etc/fstab. , . mount(8) udev, /etc/fstab . libblkid(3). proc , , - , proc - . ( none : << >> mount ). /etc/fstab, /etc/mtab /proc/mounts /etc/fstab (. fstab(5)), , , , . fstab(5) --fstab path (. ). mount -a [-t ] [-O ] (, ) fstab ( / , ) , , , noauto. -F mount . fstab mtab, . mount umount(8) /etc/mtab. /etc/mtab , Linux /etc/mtab /proc/mounts. mtab, , , Linux. mtab, , . mount , . /etc/fstab, -o: mount | -o /etc/fstab. --options-mode. , , . mount /etc/fstab, ( LABEL, UUID, ID, PARTUUID PARTLABEL) . , foo /: mount /dev/foo / --options-source-force , fstab. , root, mount fstab. . , fstab user, - . , /dev/cdrom /cd iso9660 ro,user,noauto,unhide - - iso9660 : mount /cd , mount , root, , , fstab . , mount . , NFS CIFS . util-linux 2.35, mount , libmount. suid root. , root (, ' , ). . fstab(5). , , . - , user fstab users. owner user, , . , , _/dev/fd>, . group , : . The user mount option is accepted if no username is specified. If used in the format user=someone, the option is silently ignored and visible only for external mount helpers (/sbin/mount.) for compatibility with some network filesystems. Warning When using the legacy mount(2) syscall (on older kernels without the new mount API), the mount target path is resolved by the kernel at syscall time. This means there is an inherent time-of-check-to-time-of-use (TOCTOU) window between the permission verification and the actual mount operation. If an ancestor directory of the mount target is writable by the unprivileged user, a path component could be swapped to redirect the mount to an unintended location. The new mount API (available since Linux 5.2) eliminates this issue by using file-descriptor-based target resolution. Administrators should ensure that mount target paths for user mounts do not traverse directories writable by unprivileged users. For mount source paths, mount(8) only canonicalizes (resolves symlinks) paths starting with /dev/ for unprivileged users and verifies the result stays within /dev/. Source paths outside /dev/ (e.g. disk images in user-writable directories) are kept as-is from fstab. Filesystem type auto-detection for unprivileged users relies exclusively on udev metadata rather than direct device probing; this means file images that are not registered with udev require an explicit filesystem type in fstab. ' . : mount --bind - - fstab: /- /- none bind . , <> VFS . <> . , "bind" . olddir newdir olddir . ( ). ', , : mount --bind foo foo ' () , . , , : mount --rbind - - , , , , . ( _netdev) mount - mount. util-linux 2.27, mount --bind. : mount -o bind,ro foo foo Linux; mount(2). . () ' . : mount --bind - - mount -o remount,bind,ro - - , ' ( VFS), , , _ , _ . VFS nosuid, nodev, noexec, noatime, nodiratime, relatime nosymfollow <>. ( , ) . mount(2) (, -o rbind,ro). mount_setattr(2), libmount util-linux 2.39 <<>> (, -o rbind,ro=recursive). . , . util-linux 2.31, mount bind /etc/fstab remount ( -o remount). . ', '. mount , <> /etc/fstab. Since util-linux 2.39, mount may use the new kernel mount API if it is available. This new kernel interface provides a more precise way to work with mountpoint attributes. For example, the -o bind,rw operation will create a read-write node even if the original node was read-only. This was impossible with the old classic mount(2) syscall, where the read-only VFS flag was inherited from the original node. (). : mount --move _ _ , , _>, __>. . , __ . , , , - . findmnt -o TARGET,PROPAGATION, . Linux 2.6.15, , , '. , - . , . . ' , '. Documentation/filesystems/sharedsubtree.txt ; . mount_namespaces(7). : mount --make-shared _ mount --make-slave _ mount --make-private _ mount --make-unbindable _ . mount --make-rshared _ mount --make-rslave _ mount --make-rprivate _ mount --make-runbindable _ mount fstab(5), --make-*. . , Linux mount(2), . util-linux 2.23, mount () mount(8), . mount(2), . , . fstab(5) (private, slave, shared, unbindable, rprivate, rslave, rshared, runbindable). : mount --make-private --make-unbindable /dev/sda1 /foo , mount /dev/sda1 /foo mount --make-private /foo mount --make-unbindable /foo , mount, fstab, - , -o, , -r -w, . mount /sbin/mount.. mount . mount : -a, --all Mount all filesystems (of the given types) mentioned in fstab (except for those whose line contains the noauto keyword). This option was originally designed for use in init scripts. Note that many modern systemd-based distributions do not use mount -a on boot and instead mount filesystems in a more sophisticated way using systemd units. The filesystems are mounted following their order in fstab. The mount command compares filesystem source, target (and fs root for bind mount or btrfs) to detect already mounted filesystems. The kernel table with already mounted filesystems is cached during mount --all. This means that all duplicated fstab entries will be mounted. /proc ( ) /sys ( , UUID= LABEL=) /proc /sys B /proc /sys fstab. --all . (-t -O) . 2.35 -o, fstab (. --options-mode). Note that swap entries in fstab are silently ignored by mount -a. Use swapon -a to enable swap devices and files. See swapon(8). , mount -a fstab. findmnt --verify. --beneath Mount the filesystem beneath the top mount of the specified target (mountpoint), allowing the top mount to be unmounted. This option replaces the filesystem at the mountpoint in an atomic manner, ensuring there is no moment when the filesystem is absent. For example update from a Btrfs filesystem to an XFS filesystem without ever revealing the underlying mountpoint: mount -t btrfs /dev/sdA /mnt mount --beneath -t xfs /dev/sdB /mnt umount /mnt -B, --bind ( ). . , '. -c, --no-canonicalize Do not canonicalize any paths or tags during the mount process. The mount command automatically canonicalizes all paths (from the command line or fstab). This option can be used in conjunction with the -f flag for paths that are already canonicalized. This option is intended for mount helpers that call mount -i. It is highly recommended to not use this command-line option for regular mount operations. See also the X-mount.nocanonicalize mount options. , mount /sbin/mount.. --exclusive Ensures that the filesystem is mounted as a unique instance and that the filesystem superblock is not reused by the kernel. The filesystem may be reused later if mounted without the option. The option affects only the current mount and is allowed for non-root users as well. See also the --onlyonce option. The difference between --onlyonce and --exclusive is that "onlyonce" ensures the same source is not mounted on the same mount point; this means mounting twice on /A is not allowed, but mounting on /A and /B is allowed. The "exclusive" mount ensures the filesystem itself is not reused, regardless of the mount point. -F, --fork ( -a.) mount . , NFS . . , NFS . , . , , /usr /usr/spool. -f, --fake Causes everything to be done except for the mount-related system calls. The --fake option was originally designed to write an entry to /etc/mtab without actually mounting. The /etc/mtab is no longer maintained in userspace, and starting from version 2.39, the mount operation can be a complex chain of operations with dependencies between the syscalls. The --fake option forces libmount to skip all mount source preparation, mount option analysis, and the actual mounting process. The difference between fake and non-fake execution is huge. This is the reason why the --fake option has minimal significance for the current mount(8) implementation and it is maintained mostly for backward compatibility. -i, --internal-only /sbin/mount._, . -L, --label , . -l, --show-labels . , mount ( root). ext2, ext3 ext4 e2label(8), XFS xfs_admin(8), reiserfs reiserfstune(8). -M, --move . . , . -m, --mkdir[=] ( ), . <<-o X-mount.mkdir[=]>>, - 0755. . X-mount.mkdir . --map-groups, --map-users inner:_outer_:_count_ Add the specified user/group mapping to an X-mount.idmap map. These options can be given multiple times to build up complete mappings for users and groups. For more details see X-mount.idmap below. --map-users /proc/PID/ns/user Use the specified user namespace for user and group mapping in an id-mapped mount. This is an alias for "-o X-mount.idmap=/proc/PID/ns/user" and cannot be used twice nor together with the inner:_outer_:_count_ option format above. For more details see X-mount.idmap below. -n, --no-mtab /etc/mtab. , , /etc . -N, --namespace _ Perform the mount operation in the mount namespace specified by ns. ns is either the PID of the process running in that namespace or a special file representing that namespace. mount , /etc/fstab, /etc/mtab: ( /run/mount) mount(2), . , - , mount(2). , . mount_namespaces(7). -O, --test-opts , -a. -t, , -O -a. , mount -a -O no_netdev , , netdev, /etc/fstab. -t , ; no . -t -O ; mount -a -t ext2 -O _netdev ext2 _netdev, , ext2 _netdev. -o, --options . . : mount LABEL=mydisk -o noatime,nodev,nosuid Note that the order of the options matters, as the last option wins if there are conflicting ones. Also, options on the command line override options from fstab. , . . --onlyonce Forces mount command to check if the filesystem is already mounted on specified mountpoint. This behavior is the default for --all; otherwise, it depends on the kernel filesystem driver. Some filesystems may be mounted more than once on the same mount point (e.g. tmpfs). See also --exclusive. --options-mode _> , fstab/mtab . ignore (), append ( ), prepend ( ) replace (). , append , fstab . prepend - , fstab. , . --options-source _> . fstab, mtab disable. disable fstab mtab --options-source-force. fstab,mtab. --options-source-force fstab/mtab, _>, _>. -R, --rbind ( ). . , '. -r, --ro, --read-only . , -o ro. , , , , . , ext3 ext4 , . , ext3 ext4 ro,noload , . blockdev(8). -s , . , , . . mount.nfs. --source mount, ( ) (). , . --target mount, ( ) (). , . --target-prefix . fstab, . : mount --all --target-prefix /chroot -o X-mount.mkdir fstab /chroot, ( X-mount.mkdir). . --fstab fstab. -T, --fstab fstab. , strverscmp(3); , <<.>> .fstab, . . , , initramfs chroot, . , mount(8) --fstab /sbin/mount., , fstab . , ( root) fstab . -t, --types ___> -t , . . . /proc/filesystems /lib/modules/$(uname -r)/kernel/fs, . ext2, ext3, ext4, xfs, btrfs, vfat, sysfs, proc, nfs cifs. mount umount . 'subtype'. , 'fuse.sshfs'. , (, 'sshfs#example.com' ). If no -t option is given, or if the auto type is specified, mount will try to guess the desired type. The filesystem type is determined using udev metadata first, then by direct device probing via libblkid(3) for root users. If neither method identifies the type, mount will fall back to trying all types listed in /etc/filesystems, or if that file does not exist, /proc/filesystems. Types labeled "nodev" (e.g. devpts, proc and nfs) are skipped. If /etc/filesystems ends in a line with a single *, mount will read /proc/filesystems afterwards. While trying, all filesystem types will be mounted with the mount option silent. For unprivileged (non-root) users, direct device probing via libblkid(3) is disabled and filesystem type detection relies exclusively on udev metadata. This means file images that are not registered with udev require an explicit filesystem type in fstab. Creating a file /etc/filesystems can be useful to change the probe order (e.g., to try vfat before msdos or ext3 before ext2) or if you use a kernel module autoloader. -t, /etc/fstab , . -t no, , . no , /etc/fstab. no no. , mount -a -t nomsdos,smbfs , , msdos smbfs. mount mount(2) - . , ( nfs, nfs4, cifs, smbfs, ncpfs) . nfs, nfs4, cifs, smbfs ncpfs . , mount /sbin/mount. ( ), . smbmount , /sbin/mount.smbfs , . -U, --uuid UUID , uuid. -v, --verbose . 2.41, , . -w, --rw, --read-write -. - , mount , mount(2) - . -o rw. , -w mount . -h, --help . -V, --version . , /etc/fstab. . , /proc/mounts. , (., , tune2fs -l extN). The Virtual File System (VFS) is the abstract layer in the kernel that provides the filesystem interface to userspace programs. It also provides an abstraction within the kernel which allows different filesystem implementations to coexist. Some of the mount options only apply to this layer. The options nosuid, noexec, nodiratime, relatime, noatime, strictatime, and nosymfollow are interpreted only by the virtual-filesystem kernel layer and are applied to the mountpoint node rather than to the filesystem itself. To get a complete overview of filesystems and VFS options, try: findmnt -o ,-VFS,- Since v2.39, libmount can use a new kernel mount interface to set the VFS attributes recursively. For backward compatibility, this feature is not enabled by default, even if recursive operation (e.g. rbind) has been requested. The new option argument "recursive" can be specified, for example: mount -orbind,ro=recursive,noexec=recursive,nosuid /foo /bar This recursively binds filesystems from /foo to /bar, making /bar and all submounts read-only and noexec, but only /bar itself will be "nosuid". The "recursive" optional argument for VFS mount options is an EXPERIMENTAL feature. Read-only Setting Notes The read-only setting (ro or rw) is interpreted by the virtual-filesystem and the filesystem, and it depends on how the option is specified on the mount(8) command line. For backward compatibility, the default is to use it for both layers during standard mount operations. The operation "-o bind,remount,ro" is applied only to the VFS mountpoint, while the operation "-o remount,ro" is applied to both the VFS and filesystem superblock. This semantic allows for the creation of a read-only mountpoint while keeping the filesystem writable from another mountpoint. Since version 2.41, libmount has the ability to use optional arguments vfs and fs (e.g. ro=fs) to specify where the read-only setting should be applied. For example, using the command: mount -o ro=vfs /dev/sdc1 /A will mount the filesystem as read-write on the superblock level, but the /A node will be set as read-only. In previous versions, this required an additional "-o bind,remount,ro" operation to achieve the same result. Generic Mount Options - , ( , - , sync ext2, ext3, ext4, fat, vfat, ufs xfs): async - . (. sync.) atime noatime, inode . . relatime strictatime. noatime inode (, ). inode ( ), nodiratime. auto -a. noauto ( -a ). context=, fscontext=, defcontext=, and rootcontext= context= , , , VFAT, , , , SELinux, ext3 ext4 SELinux. context= , , . , xattr, 2.4.. xattr , , . context="system_u:object_r:removable_t". fscontext= , xattr. fscontext . . , , . xattr . , fscontext, . defcontext=. , , , xattr. rootcontext= , inode . , Stateless Linux. @target , . , - , , . : . ( ), , mount . , , . : mount -t tmpfs none /mnt -o \ 'context="system_u:object_r:tmp_t:s0:c127,c456",noexec' , . selinux(8). defaults : rw, suid, dev, exec, auto, nouser async. , . . , . dev . nodev . diratime inode . . ( , noatime.) nodiratime inode . ( , noatime.) dirsync . : creat(2), link(2), unlink(2), symlink(2), mkdir(2), rmdir(2), mknod(2) rename(2). exec . noexec - . group , . nosuid nodev ( , group,dev,suid). iversion inode i_version. noiversion inode i_version. mand ' . . fcntl(2). , Linux 5.15. nomand ' . _netdev , ( , ). nofail , . relatime inode . , . ( noatime, mutt(1) , , , .) Linux 2.6.30, ( noatime). strictatime. , Linux 2.6.30, , 1 . norelatime relatime. . strictatime. strictatime atime. relatime noatime, . , . _/proc/mounts>. nostrictatime inode. lazytime (atime, mtime, ctime) inode '. inode , ' . , : o inode , ' o fsync(2), syncfs(2) sync(2) o inode ' o 24 , inode . nolazytime lazytime. suid set-user-ID set-group-ID . nosuid set-user-ID set-group-ID . , SELinux nosuid_transition, nnp_nosuid_transition. silent (silent). loud (silent). owner , . nosuid nodev ( , owner,dev,suid). remount . , , , , . . bind . . , '. The default kernel behavior for VFS mount flags (nodev,nosuid,noexec,ro) is to reset all unspecified flags on remount. That's why mount(8) tries to keep the current setting according to fstab or /proc/self/mountinfo. This default behavior is possible to change by --options-mode. The recursive change of the mount flags (supported since v2.39 on systems with mount_setattr(2) syscall), for example, mount -o remount,ro=recursive, do not use "reset-unspecified" behavior, and it works as a simple add/remove operation and unspecified flags are not modified. mount fstab. , mount fstab ( mtab), _>. mount -o remount,rw /dev/foo /dir , fstab ( mtab) , loop=, mount. mount -o remount,rw /dir mount fstab ' (-o). fstab , /proc/self/mountinfo. mount --all , (-O -t). : mount --all -o remount,ro -t vfat vfat . mount -o remount,ro /. , mount fstab mtab ' . ro[=(recursive|vfs|fs)] Mount the filesystem read-only. The optional argument is an experimental feature supported only by the file-descriptor based kernel mount API and it is silently ignored for the old mount(2) syscall. The recursive argument forces the VFS attribute to be applied recursively. The vfs and fs arguments specify the layer where the read-only flag should be applied. The fs specifies the filesystem superblock (unique filesystem instance in the kernel), and vfs specifies the mount node. If no attribute is specified, then both layers are set to read-only. For more details, please refer to the Read-only Setting Notes section. rw[=(recursive|vfs|fs)] -. sync / . (, -) sync . user . ' , , mtab ( libmount /run/mount mtab) , . noexec, nosuid nodev ( , user,exec,dev,suid). nouser . , . users - , . noexec, nosuid nodev ( , users,exec,dev,suid). X-* <> . (, mtab), mount. mount(2). *X-*_.. x-* , X-*, . , umount(8) . , , libmount , , (, ). , util-linux 2.30 x-* libmount ( , X-*), ( initrd, systemd ) fstab . X-mount.auto-fstypes= Specifies allowed or forbidden filesystem types for automatic filesystem detection. The list is a comma-separated list of the filesystem names. The automatic filesystem detection is triggered by the "auto" filesystem type or when the filesystem type is not specified. The list follows how mount evaluates type patterns (see -t for more details). Only specified filesystem types are allowed, or all specified types are forbidden if the list is prefixed by "no". For example, X-mount.auto-fstypes="ext4,btrfs" accepts only ext4 and btrfs, and X-mount.auto-fstypes="novfat,xfs" accepts all filesystems except vfat and xfs. Note that comma is used as a separator between mount options, it means that auto-fstypes values have to be properly quoted, don't forget that the shell strips off quotes and thus double quoting is required. For example: mount -t auto -o'X-mount.auto-fstypes="noext2,ext3"' /dev/sdc1 /mnt/test X-mount.mkdir[=] ( ), . , mkdir(2), . 0755. root mount suid. x-mount.mkdir, 2.30. . --mkdir. X-mount.nocanonicalize[=] Allows disabling of canonicalization for mount source and target paths. By default, the mount command resolves all paths to their absolute paths without symlinks. However, this behavior may not be desired in certain situations, such as when binding a mount over a symlink, or a symlink over a directory or another symlink. The optional argument type can be either "source" or "target" (mountpoint). If no type is specified, then canonicalization is disabled for both types. This mount option does not affect the conversion of source tags (e.g. LABEL= or UUID=) and fstab processing. The command-line option --no-canonicalize overrides this mount option and affects all path and tag conversions in all situations, but for backward compatibility, it does not modify open_tree(2) syscall flags and does not allow the bind-mount over a symlink use case. Note that mount(8) ignores this option for unprivileged (non-root) users. Target paths are always canonicalized in restricted mode to ensure safe resolution. Source paths are only canonicalized when starting with /dev/. X-mount.noloop Do not create and mount a loop device, even if the source of the mount is a regular file. X-mount.subdir= , . , . , , ' . ' . , mount(2). Note that this feature will not work in session with an unshared private mount namespace (after unshare --mount) on old kernels or with mount(8) without support for file-descriptors-based mount kernel API. In this case, you need unshare --mount --propagation shared. For unprivileged (non-root) users, this feature requires Linux >= 6.15 where the subdirectory is opened directly on the detached mount tree. This feature is EXPERIMENTAL. X-mount.owner=username|UID, X-mount.group=group|GID Set mountpoint's ownership after mounting. Names resolved in the target mount namespace, see -N. X-mount.mode= Set mountpoint's mode after mounting. X-mount.idmap=id-type:id-mount:id-host:id-range [id-type:id-mount:id-host:id-range], X-mount.idmap=file Use this option to create an idmapped mount. An idmapped mount allows to change ownership of all files located under a mount according to the ID-mapping associated with a user namespace. The ownership change is tied to the lifetime and localized to the relevant mount. The relevant ID-mapping can be specified in two ways: o A user can specify the ID-mapping directly. The ID-mapping must be specified using the syntax id-type:id-mount:id-host:id-range. Specifying u as the id-type prefix creates a UID-mapping, g creates a GID-mapping and omitting id-type or specifying b creates both a UID- and GID-mapping. The id-mount parameter indicates the starting ID in the new mount. The id-host parameter indicates the starting ID in the filesystem. The id-range parameter indicates how many IDs are to be mapped. It is possible to specify multiple ID-mappings. The individual ID mappings must be separated by spaces. Please note that in the /etc/fstab file, spaces are interpreted as separators between fields. To avoid this, you must escape them using \040. For example, X-mount.idmap=0:0:1\040500:1000:1. For example, the ID-mapping X-mount.idmap=u:1000:0:1 g:1001:1:2 5000:1000:2 creates an idmapped mount where UID 0 is mapped to UID 1000, GID 1 is mapped to GUID 1001, GID 2 is mapped to GID 1002, UID and GID 1000 are mapped to 5000, and UID and GID 1001 are mapped to 5001 in the mount. When an ID-mapping is specified directly a new user namespace will be allocated with the requested ID-mapping. The newly created user namespace will be attached to the mount. o . The user namespace will then be attached to the mount and the ID-mapping of the user namespace will become the ID-mapping of the mount. For example, X-mount.idmap=/proc/PID/ns/user will attach the user namespace of the process PID to the mount. nosymfollow . , , readlink(1), readlink(2), realpath(1) realpath(3) . , . , , . . +-----------------+---------------+ |Filesystem(s) | Manual page | +-----------------+---------------+ |btrfs | btrfs(5) | +-----------------+---------------+ |cephfs | mount.ceph(8) | +-----------------+---------------+ |cifs | mount.cifs(8) | +-----------------+---------------+ |ext2, ext3, ext4 | ext4(5) | +-----------------+---------------+ |fuse | fuse(8) | +-----------------+---------------+ |nfs | nfs(5) | +-----------------+---------------+ |tmpfs | tmpfs(5) | +-----------------+---------------+ |xfs | xfs(5) | +-----------------+---------------+ , , . . . -o. . Documentation/filesystems. adfs uid= gid= ( : uid=gid=0). ownmask= othmask= <<>> <<>> ADFS, ( : 0700 0077, ). . /usr/src/linux/Documentation/filesystems/adfs.rst. affs uid= gid= ( : uid=gid=0, uid gid UID GID ). setuid= setgid= . mode= & 0777, . , . . protect . usemp UID GID UID GID , . verbose . prefix= , , . volume= ( 30 ), <> . reserved= ( : 2.) . root= . bs= . : 512, 1024, 2048, 4096. grpquota|noquota|quota|usrquota , . (, /etc/fstab.) debugfs debugfs , /sys/kernel/debug. 3.4 debugfs : uid=n, gid=n . mode= . devpts devpts , /dev/pts. /dev/ptmx; . _/dev/pts/. uid= gid= . , UID GID , . , tty GID 5, gid=5 , tty. mode= . 0600. mode=620 gid=5 <> . newinstance devpts, , , , , devpts. devpts newinstance ( ). devpts newinstance . , , Linux. Linux, 2.6.29. , , CONFIG_DEVPTS_MULTIPLE_INSTANCES. , /dev/ptmx pts/ptmx. . Documentation/filesystems/devpts.txt Linux, . ptmxmode= ptmx devpts. devpts (. newinstance ), ptmx devpts (, /dev/pts/ptmx). ptmx 0000. ptmxmode= ptmx. , newinstance. Linux, 2.6.29. , , CONFIG_DEVPTS_MULTIPLE_INSTANCES. fat (: fat , msdos, umsdos vfat.) blocksize={512|1024|2048} ( - 512). . uid= gid= . ( : UID GID .) umask= umask ( , ). umask . . dmask= umask, . umask . . fmask= umask, . umask . . allow_utime= This option controls the permission check of mtime/atime. Possible values: 20 If the current process is in the group of the file's group ID, you can change the timestamp. 2 Other users can change the timestamp. The default is set from the above dmask option. (If the directory is writable, utime(2) is also allowed. That is: ~dmask & 022.) Normally utime(2) checks that the current process is the owner of the file, or that it has the CAP_FOWNER capability. But FAT filesystems don't have UID/GID on disk, so the normal check is too inflexible. With this option you can relax it. check= : r[elaxed] , . (, . .), ( ). n[ormal] <>, (*, ?, <, ). . s[trict] <>, , , Linux, MS-DOS (+, = ). codepage= FAT VFAT. , 437. conv= , . cvf_format= CVF (Compressed Volume File, ) cvf_ . kmod, cvf_format=xxx CVF . . cvf_option= , CVF. . debug debug. ( , ). discard , / TRIM , , . SSD /thinly-provisioned LUN. dos1xfloppy , BIOS, . , DOS 1.x 160 , 180 , 320 360 . errors={panic|continue|remount-ro} FAT : , ( ). fat={12|16|32} 12-, 16- 32- FAT. FAT. ! iocharset= , 8- 16- Unicode. iso8859-1. Unicode. nfs={stale_rw|nostale_ro} , FAT NFS. stale_rw: () inode , ' NFS . (/), NFS, ESTALE. nostale_ro: , inode FAT. , ESTALE , , inode. , , , , , , , , , . . -o nfs. stale_rw. tz=UTC ( Windows FAT) UTC ( Linux). , , (, ), UTC, . time_offset= , FAT, UTC. , , UTC, Linux. , , settimeofday(2), , . , , - . quiet . , . ! rodir FAT ATTR_RO ( ). Windows ATTR_RO . (, ). ATTR_RO , . showexec , , .EXE, .COM .BAT. , . sys_immutable , ATTR_SYS FAT IMMUTABLE Linux. , . flush , , . , . usefree << >>, FSINFO. . , Windows . , << >> FSINFO , . dots, nodots, dotsOK=[yes|no] ' Unix DOS FAT. hfs creator=cccc, type=cccc creator/type, MacOS, . : <>. uid=n, gid=n . ( : UID GID .) dir_umask=n, file_umask=n, umask=n umask , . , umask . session=n CDROM . , CDROM. - , CDROM. part=n n . CDROM. . quiet . hpfs uid= gid= . ( : UID GID .) umask= umask ( , ). umask . . case={lower|asis} . (: case=lower.) conv= , . nocheck , . iso9660 ISO 9660 - , , -. ( DVD-. . udf.) iso9660 8.3 ( DOS), , , . , , , / . Rock Ridge - iso9660, , UNIX. , , , Rock Ridge UNIX (, , ). norock Rock Ridge, . map. nojoliet Microsoft Joliet, . map. check={r[elaxed]|s[trict]} check=relaxed . , , norock map=normal. (: check=strict.) uid= gid= , , , Rock Ridge. (: uid=0,gid=0.) map={n[ormal]|o[ff]|a[corn]} , Rock Ridge, ASCII , <<;1>> <<;>> <<.>>. map=off, . . norock. (: map=normal.) map=acorn map=normal, , , Acorn. mode= , Rock Ridge, . (: .) 0. unhide ' . ( ' , .) block={512|1024|2048} . (: block=1024.) conv= , . cruft , , . , 16 . session=x Select number of session on a multisession CD, starting with 0. sbsector=xxx xxx. , vfat, , Joliet Microsoft). iocharset= 16- Unicode - 8- . iso8859-1. utf8 16- Unicode - UTF-8. jfs iocharset= Unicode ASCII. . UTF8 iocharset=utf8. .config CONFIG_NLS_UTF8. resize= . JFS , . , -. resize . nointegrity . . , . integrity . . , , nointegrity, . errors={continue|remount-ro|panic} . ( , , .) noquota|quota|usrquota|grpquota , . msdos . FAT. msdos , . , . ncpfs nfs, ncpfs (struct ncp_mount_data) mount(2). ncpmount(8), mount (2.12) ncpfs. Mount options for ntfs3 The ntfs3 kernel driver provides below mount options - as documented in iocharset= This option informs the driver how to interpret path strings and translate them to Unicode and back. If this option is not set, the default codepage will be used (CONFIG_NLS_DEFAULT). Example: iocharset=utf8 uid=|gid=|umask= Controls the default permissions for files/directories created after the NTFS volume is mounted. dmask=|fmask= Instead of specifying umask which applies both to files and directories, fmask applies only to files and dmask only to directories. nohidden Files with the Windows-specific HIDDEN (FILE_ATTRIBUTE_HIDDEN) attribute will not be shown under Linux. sys_immutable Files with the Windows-specific SYSTEM (FILE_ATTRIBUTE_SYSTEM) attribute will be marked as system immutable files. hide_dot_files Updates the Windows-specific HIDDEN (FILE_ATTRIBUTE_HIDDEN) attribute when creating and moving or renaming files. Files whose names start with a dot will have the HIDDEN attribute set and files whose names do not start with a dot will have it unset. windows_names Prevents the creation of files and directories with a name not allowed by Windows, either because it contains some not allowed character (which are the characters " * / : < > ? \ | and those whose code is less than 0x20), because the name (with or without extension) is a reserved file name (CON, AUX, NUL, PRN, LPT1-9, COM1-9) or because the last character is a space or a dot. Existing such files can still be read and renamed. discard Enable support of the TRIM command for improved performance on delete operations, which is recommended for use with the solid-state drives (SSD). force Forces the driver to mount partitions even if volume is marked dirty. Not recommended for use. sparse Create new files as sparse. showmeta Use this parameter to show all meta-files (System Files) on a mounted NTFS partition. By default, all meta-files are hidden. prealloc Preallocate space for files excessively when file size is increasing on writes. Decreases fragmentation in case of parallel write operations to different files. acl Support POSIX ACLs (Access Control Lists). Effective if supported by Kernel. Not to be confused with NTFS ACLs. The option specified as acl enables support for POSIX ACLs. overlay Linux 3.18, ' . - . , ' , ' , , , ' '. - , Linux, , . . , , , trusted.* d_type readdir, NFS . , , - . lowerdir upperdir ' : mount -t overlay overlay \ -olowerdir=/lower,upperdir=/upper,workdir=/work /merged lowerdir= - , ' . upperdir= , , . workdir= , , upperdir. userxattr xattr "user.overlay." "trusted.overlay.". . redirect_dir={on|off|follow|nofollow} redirect_dir , ( ). "{trusted|user}.overlay.redirect" . . on . off , "redirect_always_follow" /. follow , . nofollow ( "redirect_dir=off", "redirect_always_follow" ). index={on|off} inode. , , <<>>. , inode. uuid={on|off} UUID , , UUID. , , UUID . , // . , . nfs_export={on|off} NFS, <>, - NFS. <> copy_up - ' . . ', , inode. ' <<{trusted|user}.overlay.upper>> inode . ' o ', , inode o ' copy_up o ' ' inode - o (, /) o UUID o inode , <<{trusted|user}.overlay.origin>>. - o UUID . o dentry. o . o (whiteout), ESTALE. - ' , , . o , , ' dentry dentry, inode , . o ' dentry, ' dentry. , , ' dentry. copy_up ' dentry . , <<>> . <<>> , , <<>>, . , , <<>>, ' . , , . . NFS (, <>). ' , , exportfs subtree_check NFS. NFS, , , . . : index=off,nfs_export=on - . xino={on|off|auto} <> ' st_ino ' fsid. <> inode fsid, inode. inode xino, xino inode. metacopy={on|off} , overlayfs ( ), , . , WRITE. , , . volatile . , , , . <> , . , syncfs ( fsync) VFS. - , . , , - , . <>, <<$workdir/work/incompat/volatile>>. , . , . , , , <> . reiserfs Reiserfs . conv 3.6 reiserfs 3.5 3.6 '. reiserfs 3.5. hash={rupasov|tea|r5|detect} -, reiserfs . rupasov , . . , -. , -. tea -, . , - . , , - . , EHASHCOLLISION - r5. r5 - . , . detect mount -, , , , reiserfs. . hashed_relocation . . no_unhashed_relocation . . noborder , . . . nolog . reiserfs . , reiserfs , . nolog . notail , reiserfs << >> . , lilo(8). . replayonly , , . , reiserfsck. resize= , reiserfs. reiserfs , . , (LVM). resizer, . user_xattr . . attr(1). acl (ACL) POSIX. . acl(5). barrier=none / barrier=flush ' . barrier=none , barrier=flush ( ). ' -. reiserfs ' , ' -. ' , . , ' . ubifs UBIFS - -, UBI. , atime , . ubiX_Y UBI X, Y ubiY UBI 0, Y ubiX: UBI X, ubi: UBI 0, ! :. : bulk_read . VFS , . . - , , . , OneNAND << >>, NAND . no_bulk_read . . chk_data_crc CRC-32 . . no_chk_data_crc CRC-32 . CRC-32 , . , . CRC-32 . compr={none|lzo|zlib} , . , none. udf UDF - <> ( ). OSTA, Optical Storage Technology Association ( ). DVD-ROM UDF/ISO-9660. , , - . . iso9660. uid= . (, , ) uid=<>, uid=forget. UDF uid . , uid 32- uid -1, UDF. <>, , , <>. gid= . (, , ) gid=<>, gid=forget. UDF gid . , gid 32- gid -1, UDF. <>, , , <>. umask= inode, . . mode= mode=, inode, inode , , mode. . dmode= dmode=, inode , , dmode. . bs= . 2.6.30 2048. 2.6.30 4.11, 2048. 4.11, , - 4096. , mkudffs(8) 2.0+, . . unhide . undelete . adinicb inode. ( ) noadinicb inode. shortad UDF. longad UDF. ( ) nostrict . iocharset= NLS. CONFIG_UDF_NLS. utf8 UTF-8. novrs (VRS) . session= . ( = ) anchor= '. ( = 256) lastblock= . , , uid=ignore , uid=<>. gid=ignore , gid=<>. volume= , . partition= , . fileset= , . rootdir= , . ufs ufstype= UFS , . . , ufs . ufs . : old ufs, , ( -r.) 44bsd , BSD- (NetBSD, FreeBSD, OpenBSD). ufs2 FreeBSD 5.x -. 5xbsd ufs2. sun , SunOS Solaris Sparc. sunx86 , Solaris x86. hp , HP-UX, . nextstep , NeXTStep ( NeXT) ( ). nextstep-cd CDROM- NextStep (block_size == 2048), . openstep , OpenStep ( ). macOS. onerror= : panic , . lock|umount|repair . , . umsdos . msdos. dotsOK umsdos. vfat , fat. dotsOK vfat. , uni_xlate Unicode . , - Unicode. , , <>. <<:>>, vfat . , , Unicode u: <<:>>, (u & 0x3f), ((u>>6) & 0x3f), (u>>12). posix , . . nonumtail , ~.. utf8 UTF8 - 8- Unicode, . utf8=0, utf8=no utf8=false. uni_xlate, UTF8 . shortname= , <<8.3 >>. , . : lower ; , . win95 ; , . winnt ; , . mixed ; , . , Linux 2.6.32. usbfs devuid=uid, devgid=gid devmode=mode usbfs ( : uid=gid=0, mode=0644). . busuid=uid, busgid=gid busmode=mode usbfs ( : uid=gid=0, mode=0555). . listuid=uid, listgid=gid listmode=mode , ( : uid=gid=0, mode=0444). . DM-VERITY device-mapper verity . mount dm-verity . libcryptsetup libmount ( dlopen(3)). libcryptsetup - , , , . dm-verity: verity.hashdevice= -, ' , dm-verity. verity.roothash=- verity.hashdevice . verity.roothashfile. verity.roothashfile= , - verityhashdevice . verity.roothash. verity.hashoffset= - , dm-verity ( : 0). verity.fecdevice= Forward Error Correction (FEC), ' , dm-verity. '. , CONFIG_DM_VERITY_FEC. verity.fecoffset= FEC , dm-verity FEC ( : 0). '. verity.fecroots= FEC ( : 2). '. verity.roothashsig= pkcs7(1ssl) - . crypt_activate_by_signed_key() cryptsetup , CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG. , . '. verity.oncorruption={ignore|restart|panic} , , . , - . Linux 4.1 libcrypsetup 2.3.4 . '. util-linux v2.35. For example, the commands: mksquashfs /etc /tmp/etc.raw veritysetup format /tmp/etc.raw /tmp/etc.verity --root-hash-file=/tmp/etc.roothash openssl smime -sign -in /tmp/etc.roothash -nocerts -inkey private.key \ -signer private.crt -noattr -binary -outform der -out /tmp/etc.roothash.p7s mount -o verity.hashdevice=/tmp/etc.verity,verity.roothashfile=/tmp/etc.roothash,\ verity.roothashsig=/tmp/etc.roothash.p7s /tmp/etc.raw /mnt squashfs /etc, /mnt. , , roothashsig. . , mount /tmp/disk.img /mnt -t vfat -o loop=/dev/loop3 /dev/loop3, /tmp/disk.img, /mnt. ( <<-o loop>>), mount . mount /tmp/disk.img /mnt -o loop mount , libblkid. : mount /tmp/disk.img /mnt mount -t ext4 /tmp/disk.img /mnt , , loop, offset sizelimit, losetup(8). ( .) Linux 2.6.25 , , - , mount, umount /etc/mtab. , losetup -d umount -d. util-linux 2.29, mount , , . , . mount ( ): 0 1 2 ( ', , ) 4 mount 8 16 /etc/mtab 32 64 mount -a 0 ( ), 32 ( ) 64 ( , ). 126 failed to execute external /sbin/mount. mount helper (since util-linux v2.41) : /sbin/mount. spec dir [-sfnv] [-N -] [-o ] [-t .] - , -sfnvoN , . -t (, /sbin/mount.fuse -t fuse.sshfs). mount unbindable, runbindable, private, rprivate, slave, rslave, shared, rshared, auto, noauto, comment, x-*, loop, offset sizelimit mount.<>. , , -o. The exit status value of the helper is returned as the exit status of mount(8). The value 126 is sed if the mount helper program is found, but the execl() failed. LIBMOUNT_FORCE_MOUNT2={always|never|auto} force to use classic mount(2) system call (requires support for new file descriptors based mount API). The default is auto; in this case, libmount tries to be smart and use classic mount(2) only for well-known issues. If the new mount API is unavailable, libmount can still use traditional mount(2), although LIBMOUNT_FORCE_MOUNT2 is set to never. LIBMOUNT_FSTAB=<> fstab ( suid) LIBMOUNT_DEBUG=all libmount LIBBLKID_DEBUG=all libblkid LOOPDEV_DEBUG=all . " /etc/fstab, /etc/mtab /proc/mounts". /etc/fstab /run/mount libmount /etc/mtab /proc/mounts /etc/mtab~ ( mtab) /etc/mtab.tmp ( mtab) /etc/filesystems , mount AT&T UNIX 5. . Linux -o sync * -o dirsync* ( ext2, ext3, ext4, fat vfat ( BSD), sync). -o remount ( ext2fs , sb, , , gid umask fatfs). , /etc/mtab /proc/mounts mtab. mount, (, NFS - mount NFS, /proc/mount .) mtab /proc/mounts. NFS , ( fcntl ioctl), , noac. loop offset sizelimit , mount , . losetup mount . Karel Zak mount(2), umount(2), filesystems(5), fstab(5), nfs(5), xfs(5), mount_namespaces(7), xattr(7), e2label(8), findmnt(8), losetup(8), lsblk(8), mke2fs(8), mountd(8), nfsd(8), swapon(8), tune2fs(8), umount(8), xfs_admin(8) mount util-linux, Linux . util-linux 2.42.3 2026-09-02 MOUNT(8)