23 July 2013 Karim Elatov

I recently go a new Mac and I wanted to setup autofs on it, just like I did on my previous Linux Laptops. I am running Mac OS X Mountain Lion (10.8):

[email protected]:~$sw_vers
ProductName:    Mac OS X
ProductVersion: 10.8.4
BuildVersion:   12E55

AutoFS

There is a pretty good overview of AutoFS on Mac OS here:

Autofs in Leopard consists of the following programs and daemons.

autofsd autofsd runs automount, and then waits for network configuration change events and, when such an event occurs, re-runs automount to update the mounts to reflect the current automounter maps. It can also be signalled by automount_reread to run automount.

automountd automountd is a daemon that responds to requests from autofs to mount and unmount network filesystems, and to supply the contents of directories, based on the contents of automounter maps. The automountd is started on demand by launchd.

automount automount is the actual mount manager. Manages the mounting and unmounting of remote resources using several map files and configuration files. The configuration files used are /etc/autofs.conf and /etc/auto_master.

automount_reread The man pages for autofsd refer to a command called automount_reread that can trigger a network change event for autofs. However, there is no additional documentation in Leopard on that command and the command itself does not exist.

We can see that by default only autofsd is running:

[email protected]:~$ps -ef | grep auto | grep -v grep
    0    59     1   0  2:44PM ??         0:00.08 autofsd

We can also check out if the daemons are started via launchd:

[email protected]:~$sudo launchctl list | grep -E 'automo|autof'
-   0   com.apple.automountd
59  -   com.apple.autofsd

Lastly we can see what state the daemons are in:

[email protected]:~$sudo launchctl bslist | grep -E 'automo|autof'
D  com.apple.automountd

The D stands for on-demand.

Autofs Maps

With Mac OS there are a couple of options for autofs. From the Mac OS man page:

Direct Map A direct map associates filesystem locations directly with directories. The entry key is the full path name of a directory. For example:

/usr/local      eng4:/export/local
/src            eng4:/export/src

Since the direct map as a whole isn’t associated with a single directory, it is specified in the master map with a dummy directory name of /-.

Indirect Map An indirect map is used where a large number of entries are to be associated with a single directory. Each map entry key is the simple name of a directory entry. A good example of this is the auto_home map which determines the entries under the /home directory. For example:

bill    argon:/export/home/bill
brent   depot:/export/home/brent
guy     depot:/export/home/guy

I prefer to have everything that is managed by autofs in one directory, so I will go with the Indirect Map approach.

Creating an Indirect Map for AutoFS

I will use /amnt as the mount point which autofs will manage. To set this up, edit the /etc/auto_master file and add the following to it:

/amnt           autofs_amnt

The above basically says that anything under the /amnt directory will be configured under the /etc/autofs_amnt file. Next let’s add a CIFS share to be automatically mounted /amnt/smb.

Auto Mount SMB with Autofs

Let’s create the /etc/autofs_amnt file with appropriate permissions:

[email protected]:~$sudo touch /etc/autofs_amnt
[email protected]:~$sudo chmod 600 /etc/autofs_amnt

Now let’s edit the file and add the following to it:

smb -fstype=smbfs ://elatov:[email protected]/elatov

Now to apply the settings run the following:

[email protected]:~$sudo automount -vc
automount: /net updated
automount: /home updated
automount: /amnt updated
automount: no unmounts

notice /amnt is now included. If everything worked you can cd into the directory and it will automatically mount:

[email protected]:~$cd /amnt/smb
[email protected]:/amnt/smb$df -Ph .
Filesystem                           Size   Used  Avail Capacity  Mounted on
//[email protected]/elatov      3.0Ti  2.6Ti  341Gi    89%    /amnt/smb

You can use the mount command to find out the options of the mount point:

[email protected]:~$mount | grep elatov
//[email protected]/elatov on /amnt/smb (smbfs, nodev, nosuid, automounted, nobrowse, mounted by kelatov)

You will also notice automountd now running as well:

[email protected]:/amnt/smb$ps -ef | grep auto | grep -v grep
    0    59     1   0  2:44PM ??         0:00.09 autofsd
    0   930     1   0  2:15PM ??         0:00.01 automountd

If you ever want to manually un-mount the share, run the following:

[email protected]:~$umount /amnt/smb

Auto Mount NFS with Autofs

Edit the /etc/autofs_amnt file and add the following:

iso -fstype=nfs,rw,bg,hard,intr,tcp,resvport nfs.server.com:/data/isos

Apply the settings with:

sudo automount -vc

and check to make sure it is auto mounted:

[email protected]:~$cd /amnt/iso
[email protected]:/amnt/iso$df -Ph .
Filesystem                  Size   Used  Avail Capacity  Mounted on
nfs.server.com:/data/isos  3.0Ti  2.5Ti  341Gi    89%    /amnt/iso

and of course mount can show you the options:

[email protected]:~$mount | grep iso
nfs.server.com:/data/iso on /amnt/iso (nfs, nodev, nosuid, automounted, nobrowse)

Mount SSHFS with Autofs

The first thing that we need to do is install Mac Ports.

Install Mac Ports

Go to Installing MacPorts and download the pkg installer. Launch installer and you will see the following:

mac ports install Mount Various File Systems with Autofs on Mac OS X Mountain Lion

Follow the on-screen instructions install Mac Ports.

Install X-Code

X-Code is necessary for Mac Ports, so go ahead and install it from XCode. It will actually start up the App Store to do the download. After it’s done your App Store will look like this:

xcode install app store Mount Various File Systems with Autofs on Mac OS X Mountain Lion

Install X-Code Command Line tools:

Go to your Applications (Command-Shift-a) and launch X-Code (accept the license agreement). Then go to the preferences:

xcode preferences Mount Various File Systems with Autofs on Mac OS X Mountain Lion

Then go to the “Downloads” tab and install command line tools. After they are installed you will see the following under preferences:

xcode command line tools Mount Various File Systems with Autofs on Mac OS X Mountain Lion

Update Ports

Go to your “Utilities” (Command-Shift-u) and launch the terminal. From the terminal run the following:

[email protected]:~$sudo port -v selfupdate
Password:
--->  Updating MacPorts base sources using rsync
receiving file list ... done

sent 36 bytes  received 69 bytes  70.00 bytes/sec
total size is 3594240  speedup is 34230.86
receiving file list ... done

sent 36 bytes  received 76 bytes  224.00 bytes/sec
total size is 512  speedup is 4.57
MacPorts base version 2.1.3 installed,
MacPorts base version 2.1.3 downloaded.
--->  Updating the ports tree
Synchronizing local ports tree from rsync://rsync.macports.org/release/tarballs/ports.tar
receiving file list ... done

sent 36 bytes  received 70 bytes  70.67 bytes/sec
total size is 53278720  speedup is 502629.43
receiving file list ... done

sent 36 bytes  received 77 bytes  226.00 bytes/sec
total size is 512  speedup is 4.53
receiving file list ... done

sent 36 bytes  received 70 bytes  212.00 bytes/sec
total size is 9759879  speedup is 92074.33
receiving file list ... done

sent 36 bytes  received 77 bytes  75.33 bytes/sec
total size is 512  speedup is 4.53
--->  MacPorts base is already the latest version

The ports tree has been updated. To upgrade your installed ports, you should run
  port upgrade outdated

Now your ports are all up-to-date. You will also notice that that the Mac Ports install added the following into your .profile file:

[email protected]:~$cat ~/.profile
# MacPorts Installer addition on 2013-07-02_at_10:53:46: adding an appropriate PATH variable for use with MacPorts.
export PATH=/opt/local/bin:/opt/local/sbin:$PATH
# Finished adapting your PATH environment variable for use with MacPorts.

Since Mac Ports installs everything under /opt/local it needs to add /opt/local/bin/ and /opt/local/sbin/ to the path.

Install SSHFS

Mac Ports are like any package manager, it allows you to search for packages and install them. For example here is what I did to search for sshfs:

[email protected]:~$port search sshfs
sshfs @2.4 (fuse)
    SSH filesystem for FUSE

sshfs-gui @1.3 (fuse)
    OS X GUI for sshfs

Found 2 ports.

I don’t care about the GUI version. You can also check if the package has “variants”:

[email protected]:~$port variants sshfs
sshfs has the variants:
   universal: Build for multiple architectures

There aren’t that many options. A good example is something like this:

[email protected]:~$port variants mysql56
mysql56 has the variants:
   debug: Enable debug binaries
   openssl: Enable OpenSSL support
   universal: Build for multiple architectures

So if I wanted to enable debug binaries for the mysql56 package I would run the following:

sudo port install mysql56 +debug

Anyways, to install sshfs, run the following:

sudo port install sshfs

Prepare SSHFS for Autofs

First make sure you can mount with the sshfs command:

[email protected]:~$which sshfs
/opt/local/bin/sshfs
[email protected]:~$sudo mkdir /mnt/ssh
[email protected]:~$sudo chown kelatov /mnt/ssh

Now for the actual mount:

[email protected]:~$sshfs [email protected]:/mnt/data /mnt/ssh
[email protected]:~$df -Ph -T fuse4x
Filesystem                        Size   Used  Avail Capacity  Mounted on
[email protected]:/mnt/data  190Gi   80Gi  101Gi    45%    /mnt/ssh

You can un-mount the sshfs mount point like this:

[email protected]:~$umount /mnt/ssh

The way that autofs works is the type of the file system is always prepended with the mount_ prefix and that is run to actually mount that file system. So if you specify smbfs, there must be a mount_smbfs command. Here are the available mount commands on the system:

[email protected]:~$compgen -c | grep ^mount
mount
mount_acfs
mount_afp
mount_cd9660
mount_cddafs
mount_devfs
mount_exfat
mount_fdesc
mount_ftp
mount_hfs
mount_msdos
mount_nfs
mount_ntfs
mount_smbfs
mount_udf
mount_webdav

So we need to create a mount_sshfs command. We can just create a symlink to the sshfs command like so:

[email protected]:~$sudo ln -s /opt/local/bin/sshfs /sbin/mount_sshfs

Now let’s edit the /etc/autofs_amnt file and add the following:

ssh -fstype=sshfs,defer_permissions,allow_other,auto_cache [email protected]:/mnt/data

As always, refresh automount by running the following:

sudo automount -vc

Now check to make sure autofs works:

[email protected]:~$cd /amnt/ssh
[email protected]:/amnt/ssh$df -Ph .
Filesystem                     Size   Used  Avail Capacity  Mounted on
[email protected]:/mnt/data  190Gi   80Gi  101Gi    45%    /amnt/ssh

That looks good, you can check the command that was executed by autofs to mount the sshfs mountpoint:

[email protected]:/amnt/ssh2$ps -ef | grep sshfs | grep -v grep
  502  1536     1   0  3:36PM ??         0:00.00 /sbin/mount_sshfs -o nobrowse -o nosuid,nodev -o defer_permissions,allow_other,auto_cache -o automounted [email protected]:/mnt/data /amnt/ssh

If it fails for some reason, grab that command and try to mount it manually to track down any issues. If you have any mount points that are stuck, try to restart both the autofsd and automountd daemons:

[email protected]:~$sudo launchctl stop com.apple.autofsd
[email protected]:~$sudo launchctl start com.apple.autofsd
[email protected]:~$sudo launchctl stop com.apple.automountd
[email protected]:~$sudo launchctl start com.apple.automountd

autofsd is automatically restart by launchd, so you can just stop it, and it will restart it. Automountd is started by autofsd so you can just stop that as well, and as soon as you try to auto mount something, it will automatically start up. If you want to get a feeling of all the file systems that are mounted you can run the following:

[email protected]:~$lsvfs
Filesystem                        Refs Flags
-------------------------------- ----- ---------------
nfs                                  1
hfs                                  1 local, dovolfs
devfs                                0
autofs                               3
smbfs                                1
fuse4x                               1

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