rclone/docs/content/commands/rclone_mount.md
Miron Veryanskiy fd94b3a473 docs: replace #file-caching with #vfs-file-caching
The documentation had dead links pointing to #file-caching. They've been
moved to point to #vfs-file-caching.
2021-02-13 12:56:25 +00:00

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title description slug url
rclone mount Mount the remote as file system on a mountpoint. rclone_mount /commands/rclone_mount/

rclone mount

Mount the remote as file system on a mountpoint.

Synopsis

rclone mount allows Linux, FreeBSD, macOS and Windows to mount any of Rclone's cloud storage systems as a file system with FUSE.

First set up your remote using rclone config. Check it works with rclone ls etc.

On Linux and OSX, you can either run mount in foreground mode or background (daemon) mode. Mount runs in foreground mode by default, use the --daemon flag to specify background mode. You can only run mount in foreground mode on Windows.

On Linux/macOS/FreeBSD start the mount like this, where /path/to/local/mount is an empty existing directory:

rclone mount remote:path/to/files /path/to/local/mount

On Windows you can start a mount in different ways. See below for details. The following examples will mount to an automatically assigned drive, to specific drive letter X:, to path C:\path\to\nonexistent\directory (which must be non-existent subdirectory of an existing parent directory or drive, and is not supported when mounting as a network drive), and the last example will mount as network share \\cloud\remote and map it to an automatically assigned drive:

rclone mount remote:path/to/files *
rclone mount remote:path/to/files X:
rclone mount remote:path/to/files C:\path\to\nonexistent\directory
rclone mount remote:path/to/files \\cloud\remote

When the program ends while in foreground mode, either via Ctrl+C or receiving a SIGINT or SIGTERM signal, the mount should be automatically stopped.

When running in background mode the user will have to stop the mount manually:

# Linux
fusermount -u /path/to/local/mount
# OS X
umount /path/to/local/mount

The umount operation can fail, for example when the mountpoint is busy. When that happens, it is the user's responsibility to stop the mount manually.

The size of the mounted file system will be set according to information retrieved from the remote, the same as returned by the rclone about command. Remotes with unlimited storage may report the used size only, then an additional 1PB of free space is assumed. If the remote does not support the about feature at all, then 1PB is set as both the total and the free size.

Note: As of rclone 1.52.2, rclone mount now requires Go version 1.13 or newer on some platforms depending on the underlying FUSE library in use.

Installing on Windows

To run rclone mount on Windows, you will need to download and install WinFsp.

WinFsp is an open source Windows File System Proxy which makes it easy to write user space file systems for Windows. It provides a FUSE emulation layer which rclone uses combination with cgofuse. Both of these packages are by Bill Zissimopoulos who was very helpful during the implementation of rclone mount for Windows.

Mounting modes on windows

Unlike other operating systems, Microsoft Windows provides a different filesystem type for network and fixed drives. It optimises access on the assumption fixed disk drives are fast and reliable, while network drives have relatively high latency and less reliability. Some settings can also be differentiated between the two types, for example that Windows Explorer should just display icons and not create preview thumbnails for image and video files on network drives.

In most cases, rclone will mount the remote as a normal, fixed disk drive by default. However, you can also choose to mount it as a remote network drive, often described as a network share. If you mount an rclone remote using the default, fixed drive mode and experience unexpected program errors, freezes or other issues, consider mounting as a network drive instead.

When mounting as a fixed disk drive you can either mount to an unused drive letter, or to a path - which must be non-existent subdirectory of an existing parent directory or drive. Using the special value * will tell rclone to automatically assign the next available drive letter, starting with Z: and moving backward. Examples:

rclone mount remote:path/to/files *
rclone mount remote:path/to/files X:
rclone mount remote:path/to/files C:\path\to\nonexistent\directory
rclone mount remote:path/to/files X:

Option --volname can be used to set a custom volume name for the mounted file system. The default is to use the remote name and path.

To mount as network drive, you can add option --network-mode to your mount command. Mounting to a directory path is not supported in this mode, it is a limitation Windows imposes on junctions, so the remote must always be mounted to a drive letter.

rclone mount remote:path/to/files X: --network-mode

A volume name specified with --volname will be used to create the network share path. A complete UNC path, such as \\cloud\remote, optionally with path \\cloud\remote\madeup\path, will be used as is. Any other string will be used as the share part, after a default prefix \\server\. If no volume name is specified then \\server\share will be used. You must make sure the volume name is unique when you are mounting more than one drive, or else the mount command will fail. The share name will treated as the volume label for the mapped drive, shown in Windows Explorer etc, while the complete \\server\share will be reported as the remote UNC path by net use etc, just like a normal network drive mapping.

If you specify a full network share UNC path with --volname, this will implicitely set the --network-mode option, so the following two examples have same result:

rclone mount remote:path/to/files X: --network-mode
rclone mount remote:path/to/files X: --volname \\server\share

You may also specify the network share UNC path as the mountpoint itself. Then rclone will automatically assign a drive letter, same as with * and use that as mountpoint, and instead use the UNC path specified as the volume name, as if it were specified with the --volname option. This will also implicitely set the --network-mode option. This means the following two examples have same result:

rclone mount remote:path/to/files \\cloud\remote
rclone mount remote:path/to/files * --volname \\cloud\remote

There is yet another way to enable network mode, and to set the share path, and that is to pass the "native" libfuse/WinFsp option directly: --fuse-flag --VolumePrefix=\server\share. Note that the path must be with just a single backslash prefix in this case.

Note: In previous versions of rclone this was the only supported method.

Read more about drive mapping

See also Limitations section below.

Windows filesystem permissions

The FUSE emulation layer on Windows must convert between the POSIX-based permission model used in FUSE, and the permission model used in Windows, based on access-control lists (ACL).

The mounted filesystem will normally get three entries in its access-control list (ACL), representing permissions for the POSIX permission scopes: Owner, group and others. By default, the owner and group will be taken from the current user, and the built-in group "Everyone" will be used to represent others. The user/group can be customized with FUSE options "UserName" and "GroupName", e.g. -o UserName=user123 -o GroupName="Authenticated Users".

The permissions on each entry will be set according to options --dir-perms and --file-perms, which takes a value in traditional numeric notation, where the default corresponds to --file-perms 0666 --dir-perms 0777.

Note that the mapping of permissions is not always trivial, and the result you see in Windows Explorer may not be exactly like you expected. For example, when setting a value that includes write access, this will be mapped to individual permissions "write attributes", "write data" and "append data", but not "write extended attributes" (WinFsp does not support extended attributes, see this). Windows will then show this as basic permission "Special" instead of "Write", because "Write" includes the "write extended attributes" permission.

Windows caveats

Note that drives created as Administrator are not visible by other accounts (including the account that was elevated as Administrator). So if you start a Windows drive from an Administrative Command Prompt and then try to access the same drive from Explorer (which does not run as Administrator), you will not be able to see the new drive.

The easiest way around this is to start the drive from a normal command prompt. It is also possible to start a drive from the SYSTEM account (using the WinFsp.Launcher infrastructure) which creates drives accessible for everyone on the system or alternatively using the nssm service manager.

Limitations

Without the use of --vfs-cache-mode this can only write files sequentially, it can only seek when reading. This means that many applications won't work with their files on an rclone mount without --vfs-cache-mode writes or --vfs-cache-mode full. See the VFS File Caching section for more info.

The bucket based remotes (e.g. Swift, S3, Google Compute Storage, B2, Hubic) do not support the concept of empty directories, so empty directories will have a tendency to disappear once they fall out of the directory cache.

Only supported on Linux, FreeBSD, OS X and Windows at the moment.

rclone mount vs rclone sync/copy

File systems expect things to be 100% reliable, whereas cloud storage systems are a long way from 100% reliable. The rclone sync/copy commands cope with this with lots of retries. However rclone mount can't use retries in the same way without making local copies of the uploads. Look at the VFS File Caching for solutions to make mount more reliable.

Attribute caching

You can use the flag --attr-timeout to set the time the kernel caches the attributes (size, modification time, etc.) for directory entries.

The default is 1s which caches files just long enough to avoid too many callbacks to rclone from the kernel.

In theory 0s should be the correct value for filesystems which can change outside the control of the kernel. However this causes quite a few problems such as rclone using too much memory, rclone not serving files to samba and excessive time listing directories.

The kernel can cache the info about a file for the time given by --attr-timeout. You may see corruption if the remote file changes length during this window. It will show up as either a truncated file or a file with garbage on the end. With --attr-timeout 1s this is very unlikely but not impossible. The higher you set --attr-timeout the more likely it is. The default setting of "1s" is the lowest setting which mitigates the problems above.

If you set it higher (10s or 1m say) then the kernel will call back to rclone less often making it more efficient, however there is more chance of the corruption issue above.

If files don't change on the remote outside of the control of rclone then there is no chance of corruption.

This is the same as setting the attr_timeout option in mount.fuse.

Filters

Note that all the rclone filters can be used to select a subset of the files to be visible in the mount.

systemd

When running rclone mount as a systemd service, it is possible to use Type=notify. In this case the service will enter the started state after the mountpoint has been successfully set up. Units having the rclone mount service specified as a requirement will see all files and folders immediately in this mode.

chunked reading

--vfs-read-chunk-size will enable reading the source objects in parts. This can reduce the used download quota for some remotes by requesting only chunks from the remote that are actually read at the cost of an increased number of requests.

When --vfs-read-chunk-size-limit is also specified and greater than --vfs-read-chunk-size, the chunk size for each open file will get doubled for each chunk read, until the specified value is reached. A value of -1 will disable the limit and the chunk size will grow indefinitely.

With --vfs-read-chunk-size 100M and --vfs-read-chunk-size-limit 0 the following parts will be downloaded: 0-100M, 100M-200M, 200M-300M, 300M-400M and so on. When --vfs-read-chunk-size-limit 500M is specified, the result would be 0-100M, 100M-300M, 300M-700M, 700M-1200M, 1200M-1700M and so on.

VFS - Virtual File System

This command uses the VFS layer. This adapts the cloud storage objects that rclone uses into something which looks much more like a disk filing system.

Cloud storage objects have lots of properties which aren't like disk files - you can't extend them or write to the middle of them, so the VFS layer has to deal with that. Because there is no one right way of doing this there are various options explained below.

The VFS layer also implements a directory cache - this caches info about files and directories (but not the data) in memory.

VFS Directory Cache

Using the --dir-cache-time flag, you can control how long a directory should be considered up to date and not refreshed from the backend. Changes made through the mount will appear immediately or invalidate the cache.

--dir-cache-time duration   Time to cache directory entries for. (default 5m0s)
--poll-interval duration    Time to wait between polling for changes.

However, changes made directly on the cloud storage by the web interface or a different copy of rclone will only be picked up once the directory cache expires if the backend configured does not support polling for changes. If the backend supports polling, changes will be picked up within the polling interval.

You can send a SIGHUP signal to rclone for it to flush all directory caches, regardless of how old they are. Assuming only one rclone instance is running, you can reset the cache like this:

kill -SIGHUP $(pidof rclone)

If you configure rclone with a remote control then you can use rclone rc to flush the whole directory cache:

rclone rc vfs/forget

Or individual files or directories:

rclone rc vfs/forget file=path/to/file dir=path/to/dir

VFS File Buffering

The --buffer-size flag determines the amount of memory, that will be used to buffer data in advance.

Each open file will try to keep the specified amount of data in memory at all times. The buffered data is bound to one open file and won't be shared.

This flag is a upper limit for the used memory per open file. The buffer will only use memory for data that is downloaded but not not yet read. If the buffer is empty, only a small amount of memory will be used.

The maximum memory used by rclone for buffering can be up to --buffer-size * open files.

VFS File Caching

These flags control the VFS file caching options. File caching is necessary to make the VFS layer appear compatible with a normal file system. It can be disabled at the cost of some compatibility.

For example you'll need to enable VFS caching if you want to read and write simultaneously to a file. See below for more details.

Note that the VFS cache is separate from the cache backend and you may find that you need one or the other or both.

--cache-dir string                   Directory rclone will use for caching.
--vfs-cache-mode CacheMode           Cache mode off|minimal|writes|full (default off)
--vfs-cache-max-age duration         Max age of objects in the cache. (default 1h0m0s)
--vfs-cache-max-size SizeSuffix      Max total size of objects in the cache. (default off)
--vfs-cache-poll-interval duration   Interval to poll the cache for stale objects. (default 1m0s)
--vfs-write-back duration            Time to writeback files after last use when using cache. (default 5s)

If run with -vv rclone will print the location of the file cache. The files are stored in the user cache file area which is OS dependent but can be controlled with --cache-dir or setting the appropriate environment variable.

The cache has 4 different modes selected by --vfs-cache-mode. The higher the cache mode the more compatible rclone becomes at the cost of using disk space.

Note that files are written back to the remote only when they are closed and if they haven't been accessed for --vfs-write-back second. If rclone is quit or dies with files that haven't been uploaded, these will be uploaded next time rclone is run with the same flags.

If using --vfs-cache-max-size note that the cache may exceed this size for two reasons. Firstly because it is only checked every --vfs-cache-poll-interval. Secondly because open files cannot be evicted from the cache.

--vfs-cache-mode off

In this mode (the default) the cache will read directly from the remote and write directly to the remote without caching anything on disk.

This will mean some operations are not possible

  • Files can't be opened for both read AND write
  • Files opened for write can't be seeked
  • Existing files opened for write must have O_TRUNC set
  • Files open for read with O_TRUNC will be opened write only
  • Files open for write only will behave as if O_TRUNC was supplied
  • Open modes O_APPEND, O_TRUNC are ignored
  • If an upload fails it can't be retried

--vfs-cache-mode minimal

This is very similar to "off" except that files opened for read AND write will be buffered to disk. This means that files opened for write will be a lot more compatible, but uses the minimal disk space.

These operations are not possible

  • Files opened for write only can't be seeked
  • Existing files opened for write must have O_TRUNC set
  • Files opened for write only will ignore O_APPEND, O_TRUNC
  • If an upload fails it can't be retried

--vfs-cache-mode writes

In this mode files opened for read only are still read directly from the remote, write only and read/write files are buffered to disk first.

This mode should support all normal file system operations.

If an upload fails it will be retried at exponentially increasing intervals up to 1 minute.

--vfs-cache-mode full

In this mode all reads and writes are buffered to and from disk. When data is read from the remote this is buffered to disk as well.

In this mode the files in the cache will be sparse files and rclone will keep track of which bits of the files it has downloaded.

So if an application only reads the starts of each file, then rclone will only buffer the start of the file. These files will appear to be their full size in the cache, but they will be sparse files with only the data that has been downloaded present in them.

This mode should support all normal file system operations and is otherwise identical to --vfs-cache-mode writes.

When reading a file rclone will read --buffer-size plus --vfs-read-ahead bytes ahead. The --buffer-size is buffered in memory whereas the --vfs-read-ahead is buffered on disk.

When using this mode it is recommended that --buffer-size is not set too big and --vfs-read-ahead is set large if required.

IMPORTANT not all file systems support sparse files. In particular FAT/exFAT do not. Rclone will perform very badly if the cache directory is on a filesystem which doesn't support sparse files and it will log an ERROR message if one is detected.

VFS Performance

These flags may be used to enable/disable features of the VFS for performance or other reasons.

In particular S3 and Swift benefit hugely from the --no-modtime flag (or use --use-server-modtime for a slightly different effect) as each read of the modification time takes a transaction.

--no-checksum     Don't compare checksums on up/download.
--no-modtime      Don't read/write the modification time (can speed things up).
--no-seek         Don't allow seeking in files.
--read-only       Mount read-only.

When rclone reads files from a remote it reads them in chunks. This means that rather than requesting the whole file rclone reads the chunk specified. This is advantageous because some cloud providers account for reads being all the data requested, not all the data delivered.

Rclone will keep doubling the chunk size requested starting at --vfs-read-chunk-size with a maximum of --vfs-read-chunk-size-limit unless it is set to "off" in which case there will be no limit.

--vfs-read-chunk-size SizeSuffix        Read the source objects in chunks. (default 128M)
--vfs-read-chunk-size-limit SizeSuffix  Max chunk doubling size (default "off")

Sometimes rclone is delivered reads or writes out of order. Rather than seeking rclone will wait a short time for the in sequence read or write to come in. These flags only come into effect when not using an on disk cache file.

--vfs-read-wait duration   Time to wait for in-sequence read before seeking. (default 20ms)
--vfs-write-wait duration  Time to wait for in-sequence write before giving error. (default 1s)

When using VFS write caching (--vfs-cache-mode with value writes or full), the global flag --transfers can be set to adjust the number of parallel uploads of modified files from cache (the related global flag --checkers have no effect on mount).

--transfers int  Number of file transfers to run in parallel. (default 4)

VFS Case Sensitivity

Linux file systems are case-sensitive: two files can differ only by case, and the exact case must be used when opening a file.

File systems in modern Windows are case-insensitive but case-preserving: although existing files can be opened using any case, the exact case used to create the file is preserved and available for programs to query. It is not allowed for two files in the same directory to differ only by case.

Usually file systems on macOS are case-insensitive. It is possible to make macOS file systems case-sensitive but that is not the default

The --vfs-case-insensitive mount flag controls how rclone handles these two cases. If its value is "false", rclone passes file names to the mounted file system as-is. If the flag is "true" (or appears without a value on command line), rclone may perform a "fixup" as explained below.

The user may specify a file name to open/delete/rename/etc with a case different than what is stored on mounted file system. If an argument refers to an existing file with exactly the same name, then the case of the existing file on the disk will be used. However, if a file name with exactly the same name is not found but a name differing only by case exists, rclone will transparently fixup the name. This fixup happens only when an existing file is requested. Case sensitivity of file names created anew by rclone is controlled by an underlying mounted file system.

Note that case sensitivity of the operating system running rclone (the target) may differ from case sensitivity of a file system mounted by rclone (the source). The flag controls whether "fixup" is performed to satisfy the target.

If the flag is not provided on the command line, then its default value depends on the operating system where rclone runs: "true" on Windows and macOS, "false" otherwise. If the flag is provided without a value, then it is "true".

rclone mount remote:path /path/to/mountpoint [flags]

Options

      --allow-non-empty                        Allow mounting over a non-empty directory. Not supported on Windows.
      --allow-other                            Allow access to other users. Not supported on Windows.
      --allow-root                             Allow access to root user. Not supported on Windows.
      --async-read                             Use asynchronous reads. Not supported on Windows. (default true)
      --attr-timeout duration                  Time for which file/directory attributes are cached. (default 1s)
      --daemon                                 Run mount as a daemon (background mode). Not supported on Windows.
      --daemon-timeout duration                Time limit for rclone to respond to kernel. Not supported on Windows.
      --debug-fuse                             Debug the FUSE internals - needs -v.
      --default-permissions                    Makes kernel enforce access control based on the file mode. Not supported on Windows.
      --dir-cache-time duration                Time to cache directory entries for. (default 5m0s)
      --dir-perms FileMode                     Directory permissions (default 0777)
      --file-perms FileMode                    File permissions (default 0666)
      --fuse-flag stringArray                  Flags or arguments to be passed direct to libfuse/WinFsp. Repeat if required.
      --gid uint32                             Override the gid field set by the filesystem. Not supported on Windows. (default 1000)
  -h, --help                                   help for mount
      --max-read-ahead SizeSuffix              The number of bytes that can be prefetched for sequential reads. Not supported on Windows. (default 128k)
      --network-mode                           Mount as remote network drive, instead of fixed disk drive. Supported on Windows only
      --no-checksum                            Don't compare checksums on up/download.
      --no-modtime                             Don't read/write the modification time (can speed things up).
      --no-seek                                Don't allow seeking in files.
      --noappledouble                          Ignore Apple Double (._) and .DS_Store files. Supported on OSX only. (default true)
      --noapplexattr                           Ignore all "com.apple.*" extended attributes. Supported on OSX only.
  -o, --option stringArray                     Option for libfuse/WinFsp. Repeat if required.
      --poll-interval duration                 Time to wait between polling for changes. Must be smaller than dir-cache-time. Only on supported remotes. Set to 0 to disable. (default 1m0s)
      --read-only                              Mount read-only.
      --uid uint32                             Override the uid field set by the filesystem. Not supported on Windows. (default 1000)
      --umask int                              Override the permission bits set by the filesystem. Not supported on Windows.
      --vfs-cache-max-age duration             Max age of objects in the cache. (default 1h0m0s)
      --vfs-cache-max-size SizeSuffix          Max total size of objects in the cache. (default off)
      --vfs-cache-mode CacheMode               Cache mode off|minimal|writes|full (default off)
      --vfs-cache-poll-interval duration       Interval to poll the cache for stale objects. (default 1m0s)
      --vfs-case-insensitive                   If a file name not found, find a case insensitive match.
      --vfs-read-ahead SizeSuffix              Extra read ahead over --buffer-size when using cache-mode full.
      --vfs-read-chunk-size SizeSuffix         Read the source objects in chunks. (default 128M)
      --vfs-read-chunk-size-limit SizeSuffix   If greater than --vfs-read-chunk-size, double the chunk size after each chunk read, until the limit is reached. 'off' is unlimited. (default off)
      --vfs-read-wait duration                 Time to wait for in-sequence read before seeking. (default 20ms)
      --vfs-write-back duration                Time to writeback files after last use when using cache. (default 5s)
      --vfs-write-wait duration                Time to wait for in-sequence write before giving error. (default 1s)
      --volname string                         Set the volume name. Supported on Windows and OSX only.
      --write-back-cache                       Makes kernel buffer writes before sending them to rclone. Without this, writethrough caching is used. Not supported on Windows.

See the global flags page for global options not listed here.

SEE ALSO

  • rclone - Show help for rclone commands, flags and backends.