SSHFS

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SSHFS 是一个通过 SSH 挂载基于 FUSE 的文件系统的客户端程序。

注意： 开发者已经停止开发此项目，rclone^包提供了相同的挂载功能。

安装[编辑 | 编辑源代码]

安装软件包 sshfs^包。

提示：

If you often need to mount sshfs filesystems you may be interested in using an sshfs helper, such as qsshfs^AUR, sftpman, sshmnt^AUR or fmount.py.
You may want to use Google Authenticator providing additional security as in two-step authentication.
SSH keys may be used over traditional password authentication.

挂载[编辑 | 编辑源代码]

只能挂载 SSH 用户可以访问的目录，用 sshfs 挂载远程目录：

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

示例:

$ sshfs myuser@mycomputer:/remote/path /local/path -C -p 9876

-p 9876 指定端口号，-C 启用压缩。

未指定是默认挂载远程用户的主目录，默认的用户名和密码可以通过 ~/.ssh/config 按主机进行配置，这样可以简化 sshfs 命令。详情请参考 OpenSSH#Client usage。

需要密码时，SSH 会提示输入，如果不想一直手动输入，可以使用 SSH keys。

卸载[编辑 | 编辑源代码]

要卸载远程系统:

$ fusermount3 -u mountpoint

例如:

$ fusermount3 -u /local/path

选项[编辑 | 编辑源代码]

sshfs can automatically convert between local and remote user IDs. Use the idmap=user option to translate the UID of the connecting user to the remote user myuser (GID remains unchanged):

$ sshfs myuser@mycomputer:/remote/path /local/path -o idmap=user

If you need more control over UID and GID translation, look at the options idmap=file, uidfile and gidfile.

A complete list of options can be found in sshfs(1).

Chrooting[编辑 | 编辑源代码]

You may want to restrict a specific user to a specific directory on the remote system. This can be done by editing /etc/ssh/sshd_config:

/etc/ssh/sshd_config

.....
Match User someuser 
       ChrootDirectory /chroot/%u
       ForceCommand internal-sftp
       AllowTcpForwarding no
       X11Forwarding no
.....

注意： The chroot directory must be owned by root, otherwise you will not be able to connect.

See also SFTP chroot. For more information check the sshd_config(5) man page for Match, ChrootDirectory and ForceCommand.

Automounting[编辑 | 编辑源代码]

Automounting can happen on boot, or on demand (when accessing the directory). For both, the setup happens in the fstab.

注意： Keep in mind that automounting is done through the root user, therefore you cannot use hosts configured in .ssh/config of your normal user.

To let the root user use an SSH key of a normal user, specify its full path in the IdentityFile option.

And most importantly, use each sshfs mount at least once manually while root on the client machine so the host's signature is added to the client's /root/.ssh/known_hosts file. This can also be done manually by appending one or more of the the SSH server's public host keys (the /etc/ssh/ssh_host_*key.pub files) to /root/.ssh/known_hosts.

On demand[编辑 | 编辑源代码]

这篇文章的某些内容需要扩充。

原因： Is there a way to make this work with a passphrase-protected private key? E.g. it prompts for the passphrase at first access. Alternatively, clearly state that it is not possible and why. (在 Talk:SSHFS 中讨论)

With systemd on-demand mounting is possible using /etc/fstab entries.

Example:

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

The important mount options here are noauto,x-systemd.automount,_netdev.

noauto tells it not to mount at boot
x-systemd.automount does the on-demand magic
_netdev tells it that it is a network device, not a block device (without it "No such device" errors might happen)

注意： After editing /etc/fstab, reload the systemd configuration and the required services, which can be found by running systemctl list-unit-files --type automount

On boot[编辑 | 编辑源代码]

An example on how to use sshfs to mount a remote filesystem through /etc/fstab

user@host:/remote/path  /local/path  fuse.sshfs  defaults,_netdev  0  0

Take for example the fstab line

llib@192.168.1.200:/home/llib/FAH  /media/FAH2  fuse.sshfs  defaults,_netdev  0  0

The above will work automatically if you are using an SSH key for the user. See Using SSH Keys.

If you want to use sshfs with multiple users, add the following option:

user@domain.org:/home/user  /media/user   fuse.sshfs    defaults,allow_other,_netdev    0  0

In order to ensure the network is available before trying to mount, it is not only important to set the _netdev mount option, but also to add either --any or a specific --interface to the appropriate wait-online service for your network manager.

Secure user access[编辑 | 编辑源代码]

When automounting via fstab, the filesystem will generally be mounted by root. By default, this produces undesireable results if you wish access as an ordinary user and limit access to other users.

An example mountpoint configuration:

user@host:/remote/path /local/path  fuse.sshfs noauto,x-systemd.automount,_netdev,user,idmap=user,follow_symlinks,identityfile=/home/user/.ssh/id_rsa,allow_other,default_permissions,uid=USER_ID_N,gid=USER_GID_N 0 0

Summary of the relevant options:

allow_other - Allow other users than the mounter (i.e. root) to access the share.
default_permissions - Allow kernel to check permissions, i.e. use the actual permissions on the remote filesystem. This allows prohibiting access to everybody otherwise granted by allow_other.
uid, gid - set reported ownership of files to given values; uid is the numeric user ID of your user, gid is the numeric group ID of your user.

Troubleshooting[编辑 | 编辑源代码]

Checklist[编辑 | 编辑源代码]

Read OpenSSH#Checklist first. Further issues to check are:

Is your SSH login sending additional information from server's /etc/issue file e.g.? This might confuse SSHFS. You should temporarily deactivate server's /etc/issue file:
```
$ mv /etc/issue /etc/issue.orig
```
Keep in mind that most SSH related troubleshooting articles you will find on the web are not systemd related. Often /etc/fstab definitions wrongly begin with
```
sshfs#user@host:/mnt/server/directory ... fuse ...
```
instead of using the syntax
```
user@host:/mnt/server/directory ... fuse.sshfs ... x-systemd, ...
```
Check that the owner of server's source directory and content is owned by the server's user.
```
$ chown -R user_s: /mnt/servers/directory
```
The server's user ID can be different from the client's one. Obviously both user names have to be the same. You just have to care for the client's user IDs. SSHFS will translate the UID for you with the following mount options:
```
uid=USER_C_ID,gid=GROUP_C_ID
```
Check that the client's target mount point (directory) is owned by the client user. This directory should have the same user ID as defined in SSHFS's mount options.
```
$ chown -R user_c: /mnt/client/directory
```
Check that the client's mount point (directory) is empty. By default you cannot mount SSHFS directories to non-empty directories.

Connection reset by peer[编辑 | 编辑源代码]

If you are trying to access the remote system with a hostname, try using its IP address, as it can be a domain name resolving issue. Make sure you edit /etc/hosts with the server details.
Make sure your user can log into the server (especially when using AllowUsers).
Make sure Subsystem sftp /usr/lib/ssh/sftp-server is enabled in /etc/ssh/sshd_config on the remote system.
If you are using a non-default key name and passing it as -i .ssh/my_key, this will not work. You have to use -o IdentityFile=/home/user/.ssh/my_key, with the full path to the key.
If your /root/.ssh/config/ is a symlink, you will be getting this error as well. See this serverfault topic
Adding the option sshfs_debug (as in sshfs -o sshfs_debug user@server ...) can help in resolving the issue.
If that does not reveal anything useful, you might also try adding the option debug.
If you are trying to sshfs into a router running DD-WRT or the like, there is a solution here. (Note that the -osftp_server=/opt/libexec/sftp-server option can be used to the sshfs command instead of patching dropbear).
If you see this only on boot, it may be that systemd is attempting to mount prior to a network connection being available. Enabling the appropriate wait-online service for your network manager fixes this.
Old Forum thread: sshfs: Connection reset by peer.

注意： When providing more than one option for sshfs, they must be comma separated. Like so: sshfs -o sshfs_debug,IdentityFile=/path/to/key user@server ...).

Remote host has disconnected[编辑 | 编辑源代码]

If you receive this message directly after attempting to use sshfs:

First make sure that the remote machine has sftp installed! It will not work, if not.
Then, check that the path of the Subsystem sftp in /etc/ssh/sshd_config on the remote machine is valid.

fstab mounting issues[编辑 | 编辑源代码]

To get verbose debugging output, add the following to the mount options:

ssh_command=ssh\040-vv,sshfs_debug,debug

注意： Here, \040 represents a space which fstab uses to separate fields.

To be able to run mount -av and see the debug output, remove the following:

 noauto,x-systemd.automount

Some directories are empty[编辑 | 编辑源代码]

sshfs by default does not support symlinks. If those directories happened to be symlinks, use:

$ sshfs user@host:/remote/path /local/path -o follow_symlinks

Files not refreshed[编辑 | 编辑源代码]

If you see old content on remote, consider using option dir_cache=no:

$ sshfs user@host:/remote/path /local/path -o dir_cache=no

Limited transfer on fast network[编辑 | 编辑源代码]

If you observe transfer than is lower than your network capabilities and high CPU usage on the party where files are copied from, disable compression (remove -C option or set -o compression=no).