1 MOUNT_TMPFS(1M) Maintenance Commands MOUNT_TMPFS(1M) 2 3 4 5 NAME 6 mount_tmpfs - mount tmpfs file systems 7 8 SYNOPSIS 9 mount [-F tmpfs] [-o specific_options] [-O] special mount_point 10 11 12 DESCRIPTION 13 tmpfs is a memory based file system which uses kernel resources 14 relating to the VM system and page cache as a file system. 15 16 17 mount attaches a tmpfs file system to the file system hierarchy at the 18 pathname location mount_point, which must already exist. If mount_point 19 has any contents prior to the mount operation, these remain hidden 20 until the file system is once again unmounted. The attributes (mode, 21 owner, and group) of the root of the tmpfs filesystem are inherited 22 from the underlying mount_point, provided that those attributes are 23 determinable. If not, the root's attributes are set to their default 24 values. The mode may also be overridden by the mode mount option, which 25 takes precedence if set. 26 27 28 The special argument is usually specified as swap but is in fact 29 disregarded and assumed to be the virtual memory resources within the 30 system. 31 32 OPTIONS 33 -o specific_options 34 Specify tmpfs file system specific options in a 35 comma-separated list with no intervening spaces. 36 If invalid options are specified, a warning 37 message is printed and the invalid options are 38 ignored. The following options are available: 39 40 remount 41 42 Remounts a file system with a 43 new size. A size not 44 explicitly set with remount 45 reverts to no limit. 46 47 48 mode=octalmode 49 The mode argument controls 50 the permissions of the tmpfs 51 mount point. The argument 52 must be an octal number, of 53 the form passed to chmod(1). 54 Only the access mode, setuid, 55 setgid, and sticky bits (a 56 mask of 07777) may be set. 57 If this option is not 58 provided then the default 59 mode behaviour, as described 60 above, applies. 61 62 63 64 size=sz 65 The sz argument controls the 66 size of this particular tmpfs 67 file system. If the argument 68 is has a `k' suffix, the 69 number will be interpreted as 70 a number of kilobytes. An `m' 71 suffix will be interpreted as 72 a number of megabytes. A `g' 73 suffix will be interpreted as 74 a number of gigabytes. A `%' 75 suffix will be interpreted as 76 a percentage of the swap 77 space available to the zone. 78 No suffix is interpreted as 79 bytes. In all cases, the 80 actual size of the file 81 system is the number of bytes 82 specified, rounded up to the 83 physical pagesize of the 84 system. 85 86 87 xattr | noxattr 88 Allow or disallow the 89 creation and manipulation of 90 extended attributes. The 91 default is xattr. See 92 fsattr(5) for a description 93 of extended attributes. 94 95 96 97 -O 98 Overlay mount. Allow the file system to be 99 mounted over an existing mount point, making the 100 underlying file system inaccessible. If a mount 101 is attempted on a pre-existing mount point 102 without setting this flag, the mount will fail, 103 producing the error: device busy. 104 105 106 FILES 107 /etc/mnttab 108 Table of mounted file systems 109 110 111 SEE ALSO 112 mount(1M), mkdir(2), mount(2), open(2), umount(2), mnttab(4), 113 attributes(5), fsattr(5), tmpfs(7FS) 114 115 NOTES 116 If the directory on which a file system is to be mounted is a symbolic 117 link, the file system is mounted on the directory to which the symbolic 118 link refers, rather than on top of the symbolic link itself. 119 120 121 122 March 18, 2015 MOUNT_TMPFS(1M)