knowledge/technology/linux/filesystems/SSHFS.md

arch-wiki	obj	rev
https://wiki.archlinux.org/title/SSHFS	filesystem	2024-08-26

SSHFS

SSHFS is a FUSE Filesystem based on the SSH and SFTP Protocol.

Mounting

sshfs [user@]host:[dir] mountpoint [options]

Automount

fstab entry:

user@host:/remote/path /local/path  fuse.sshfs noauto,x-systemd.automount,_netdev,users,idmap=user,IdentityFile=/home/user/.ssh/id_rsa,allow_other,reconnect 0 0

Options

Option	Description
-p PORT	SSH Port, equivalent to -o port=PORT
-f	do not daemonize, stay in foreground.
-s	Single threaded operation.
-C	Enable Compression, equivalent to -o compression=yes
-F ssh_configfile	specifies alternative ssh configuration file
-o reconnect	automatically reconnect to server if connection is interrupted. Attempts to access files that were opened before the reconnection will give errors and need to be re-opened.
-o delay_connect	Don't immediately connect to server, wait until mountpoint is first accessed.
-o sshfs_sync	synchronous writes. This will slow things down, but may be useful in some situations.
-o no_readahead	Only read exactly the data that was requested, instead of speculatively reading more to anticipate the next read request.
-o sync_readdir	synchronous readdir. This will slow things down, but may be useful in some situations.
-o idmap=TYPE	How to map remote UID/GIDs to local values. none: no translation of the ID space (default). user: map the UID/GID of the remote user to UID/GID of the mounting user. file: translate UIDs/GIDs based upon the contents of --uidfile and --gidfile.
-o uidfile=FILE	file containing username:uid mappings for -o idmap=file
-o gidfile=FILE	file containing groupname:gid mappings for -o idmap=file
-o ssh_command=CMD	execute CMD instead of 'ssh'
-o transform_symlinks	transform absolute symlinks on remote side to relative symlinks. This means that if e.g. on the server side /foo/bar/com is a symlink to /foo/blub, SSHFS will transform the link target to ../blub on the client side.
-o follow_symlinks	follow symlinks on the server, i.e. present them as regular files on the client. If a symlink is dangling (i.e, the target does not exist) the behavior depends on the remote server - the entry may appear as a symlink on the client, or it may appear as a regular file that cannot be accessed.
-o no_check_root	don't check for existence of 'dir' on server
-o dir_cache=BOOL	Enables (yes) or disables (no) the SSHFS directory cache. The directory cache holds the names of directory entries. Enabling it allows readdir system calls to be processed without network access.
-o dcache_max_size=N	sets the maximum size of the directory cache.
-o dcache_timeout=N	sets timeout for directory cache in seconds.
-o dcache_{stat,link,dir}_timeout=N	sets separate timeout for {attributes, symlinks, names} in the directory cache.
-o dcache_clean_interval=N	sets the interval for automatic cleaning of the directory cache.
-o dcache_min_clean_interval=N	sets the interval for forced cleaning of the directory cache when full.
-o direct_io	This option disables the use of page cache (file content cache) in the kernel for this filesystem.
-o max_conns=N	sets the maximum number of simultaneous SSH connections to use. Each connection is established with a separate SSH process. The primary purpose of this feature is to improve the responsiveness of the file system during large file transfers.