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@@ -0,0 +1,263 @@ +SSHFS FAQ +========= + +1. I've found a bug and there's no solution in this FAQ, what + should I do? +2. Advantage of sshfs over NFS and Samba +3. Create the device node +4. mv fails with "Operation not permitted" +5. cvs fails with "cvs [status aborted]: cannot get working + directory: No such file or directory" in a sshfs mounted directory +6. Changes on the server are not immediately visible in the + mounted directory. +7. Configuring the ssh connection +8. What are the no_readahead and sshfs_sync options for? +9. Why does df return strange values on partitions mounted via + sshfs? +10. How do I specify the remote mount point (since the example + defaults to the home directory) +11. sshfs hangs after a while +12. Following symlinks on the server side +13. Making absolute symlinks work +14. Mounting as root +15. Exporting via NFS +16. Automatical mounting using /etc/fstab +17. Why does SVN (etc...) fail with permission denied? +18. Why does SVN (etc...) fail to rename files? +19. Is there some neat way to do it in reverse? +20. Might it be reasonable to disallow loops? +21. How to mount through an intermediary ssh server, eg: + localhost -> A -> B; mount B from localhost +22. Alternative Solution +23. I seem to have successfully mounted a remote directory, but + performing an `ls -l` on the directory above the mount point shows + the mount point's attributes as `? ? ? ? ? ?`. Nothing shows up in + the directory either. What am I doing wrong? + +-------------------------------------------------------------------------- + +1. I've found a bug and there's no solution in this FAQ, what should I do? + + Please report the bug in the Github issue tracker: + https://github.com/libfuse/sshfs/issues + + Also logs with debugging output can be useful for diagnosing the + problem. Try running sshfs with the following options: + sshfs -odebug,sshfs_debug,loglevel=debug ... + + Doing strace on the application which fails may also sometimes help: + strace -f -o /tmp/strace application args ... + + Note that large messages (over 40k) will be rejected from the mailing + list. So try to keep the logs as short as possible. + + +2. Advantage of sshfs over NFS and Samba + + Users can mount remote resources they already have ssh access to, + without requiring the remote machine to export the resource. + + The remote resource can be mounted when it is needed in a location + that is convenient for the user at that time, without needing to rely + on a central, root-controlled file system table. + + Automatic mounting, if desired, can be added to a shell script such as + .bashrc (provided authentication is done using RSA/DSA keys). + + Resources can be mounted over slow and unreliable (distant) + connections. + +3. Create the device node + + If you don't use udev, you may get this error message: + + fusermount: failed to open /dev/fuse: No such device or address + + Before loading the fuse kernel module, create the device node + manually: + + mknod -m 666 /dev/fuse c 10 229 + +4. mv fails with "Operation not permitted". + + Use -o workaround=rename (requires sshfs version >= 1.3). + +5. cvs fails with "cvs status aborted?: cannot get working directory: No such + file or directory" in a sshfs mounted directory + + Use the -oreaddir_ino option. Example: + sshfs -oreaddir_ino hostname:remote_dir mount_point + +6. Changes on the server are not immediately visible in the mounted directory. + + By default, sshfs caches things for 20 seconds, use -o cache_timeout=N + to change the default cache timeout (in seconds) or -o cache=no for + disabling the cache. + + You can also control cache timeouts for directory listing etc with + -o cache_stat_timeout=N, + -o cache_dir_timout=N, and + -o cache_link_timout=N. + +7. Configuring the ssh connection + + In addition to flags like -C, -p, and -o SSHOPT...=, you may find it + easier to edit your /.ssh/config file. You can add an entry with any + customization you want, test it with ssh, and finally use it with + sshfs. As a bonus, you get a short mnemonic for your configuration. + +8. What are the no_readahead and sshfs_sync options for? + + These disable read and write optimizations respectively. They don't + really make sense unless you're doing something special. + +9. Why does df return strange values on partitions mounted via sshfs? + + Because the SFTP protocol doesn't have a statfs operation this is + currently not possible to display proper usage on remote partition. + +10. How do I specfy the remote mount point (since the example defaults to the + home directory) + + The example shows: + sshfs hostname: mountpoint + + To specify a remote mount point use: + sshfs hostname:remotemountpoint mountpoint + + This might be obvious to others, but I ended up looking up the + interface to sftp to see if I could learn how to specify the remote + mount point, then thought about the way that scp specifies the remote + directory, and it worked. + +11. sshfs hangs after a while + + Mounting works fine, I can use the files in Mountpoint as good as any + other files on my system, but after bit of time, changing nothing on + the remote files sshfs crashes. This means, I can not cd into the + Mountpoint (xterm hangs, nautilus hangs... every program trying to + access the Mountpoint gets stuck, and won't return). + + Solution: add + ServerAliveInterval 15 + + in your .ssh/config (or use -o ServerAliveInterval=15 on the sshfs + command line but I did not test that solution). This will force the + ssh connection to stay alive even if you have no activity. + +12. Following symlinks on the server side + + The -o follow_symlinks option will enable this. + +13. Making absolute symlinks work + + Use the -o transform_symlinks option, which will transform absolute + symlinks (ones which point somewhere inside the mount) into relative + ones. + +14. Mounting as root + + Generally it's not possible to use an sshfs mount as a "real" + filesystem shared between multiple users. Some of this functionality + can be enabled with the -o allow_other and -o default_permissions + options, but files will not be created with the correct ownership, + etc... + +15. Exporting via NFS + + Use the userspace NFS daemon http://sourceforge.net/projects/unfs + +16. Automatical mounting using /etc/fstab + + A line in /etc/fstab has the following format: + sshfs#USERNAME@REMOTE_HOST:REMOTE_PATH MOUNT_POINT fuse SSHFS_OPTIONS 0 0 + + eg. + sshfs#guest@guest.login.com:data /mnt/guest fuse \ + uid=1003,gid=100,umask=0,allow_other 0 0 + +17. Why does SVN (etc...) fail with permission denied? + + This is a bug that happens when an application creates a read-only + file opened for writing (e.g. open("foo", O_WRONLY|O_CREAT, 0444)) + + It has been fixed in sshfs version 1.3, but also requires FUSE version + >=2.5.X and Linux kernel version >=2.6.15. + +18. Why does SVN (etc...) fail to rename files? + + $ svn co svn://anonsvn.kde.org/home/kde/trunk/KDE/kdelibs + svn: Can't move 'kdelibs/.svn/tmp/entries' to 'kdelibs/.svn/entries': + Operation not permitted + + The reason is that SFTP protocol version 3 (which is implemented by + OpenSSH's sftp-server) defines the rename operation slightly + differently than POSIX. The difference is that renaming to an existing + file or directory will fail instead of atomically replacing the old + file. + + The -o workaround=rename option will try to emulate POSIX rename + semantics, but it cannot guarantee atomicity. In most of the cases + this doesn't matter, and things will work fine with this option. + +19. Is there some neat way to do it in reverse? + + You want to mount a USB thumb drive onto a file server that is rather + remote. + + Assuming this is difficult because the laptop with the thumb drive is + sitting behind NAT, firewalls, etc. then you need to create a + port-forward: + client$ ssh -R 2222:localhost:22 server + server$ sshfs -p 2222 localhost:/media/usb1 myusb1 + + (Now, is there is there a smarter way that does not involve port + opening login permissions in an undesireable direction?) + +20. Might it be reasonable to disallow loops? + + sshfs localhost:/mnt /mnt + + This seems to produce undesirable results. --JoshuaRodman + +21. How to mount through an intermediary ssh server, eg: localhost -> A -> B; + mount B from localhost + + Start by mounting the folder you need that is on "a" to a folder on + "b" then mount the new folder that is on "a" to a folder on localhost. + + IE: (These are NOT real commands, but a sequence of steps. + A mounts B:/home/x on /mnt/Bx + localhost mounts A:/mnt/Bx on ~/mydir + +22. Alternative Solution: + + 1) Create a shell script to wrap the tunneling of one ssh command over + another, + $ cat >Atunnel <<EOF + #!/bin/bash + ssh -q A ssh -q "$@" + EOF + $ chmod u+x Atunnel + + N.B. make sure to put this somewhere on your path. 2) sshfs mount as + normal but using this script as the ssh command. + $ sshfs -o ssh_command='Atunnel' B: ~/mydir + +23. I seem to have successfully mounted a remote directory, but performing an + `ls -l` on the directory above the mount point shows the mount point's + attributes as `? ? ? ? ? ?`. Nothing shows up in the directory either. What + am I doing wrong? + + You probably specified a remote path with the tilde (~) in it. This + doesn't seem to work. Instead, specify an absolute remote path: + sshfs username@remote.host:/home/username/whatever my/mount + + What options do i use to make playing media files (music) over sshfs more + efficient? + + MacFUSE doesn't seem to let me move files from one directory to another. It + first asks for my local user password (i.e. the password on my Macbook Pro) + and then produces the error message "The operation cannot be completed + because one or more required items cannot be found. (Error code -120). + |