Automount NAS share on Mac


It's been several years since I was sold on using a NAS to solve the data sharing problems at home. QNAP TS-439 Pro was my choice. Frequent firmware updates kept it up to date and relevant. When something becomes popular, say Google Drive, you get a firmware update that integrates it to NAS. One firmware for all versions of QNAP, new and old. So, your old hardware does not become irrelevant in a year or two.

SMB Versions / Issues

Traditionally AFP (Apple Filing Protocol) was the protocol preferred on Macs for network access. Of course, Windows used SMB (Server Message Block) protocol of Microsoft. Currently Windows 8.1 uses SMB v3. With Maverick (v10.9) release, Apple backed away from their own AFP protocol in support of SMB v2, and that was a problematic release to say the least. With 10.10 Yosemite Mac OS X supports v3 as the default sharing protocol.

QNAP, unfortunately, does not support SMB 3.0. With the release of firmware 4.1.0 Build 0605, QNAP changed samba default protocol to SMB 2.0

SMB Nightmare
After upgrading my Macs to 10.10, I started connecting to my QNAP via SMB 2.0, and problems started. The biggest issue was that whenever I wanted to copy a bunch of files to NAS, it would start copying, and after the first one or two, I would get an error that read:

"Operation cannot be completed because file is in use",

and copy would fail.

I could workaround the problem by going to terminal and use 'scp' to transfer files to NAS, but it was not that convenient.

Many people complained about this problem on Apple forums. None of the solutions offered helped in my case, so I went back to AFP, and that problem disappeared. I still see other issues when, for example, editing a word document: Word somehow cannot save the file the first time, then lock is released and file is saved. That's more of an Microsoft office problem, rather than AFP/SMB though.

Automounting NAS

One problem that annoyed me was that even with AFP, I had to connect to my NAS over and over. It was not as bad as SMB which kept on prompting me, but it was still an hassle, especially on my Macbook, which is not always near my wifi to connect to home NAS.

Over the weekend, I took another look at Apple's Autofs: Automatically Mounting Network Files Shares whitepaper  and implemented it for my macs.

The implementation is simple. Apple now has /etc/auto_master file, which can lookup other files for indirect mounting information and automatically carry out the mount instructions.

adil-imac-1:~ adil$ ls /etc/auto*

-rw-r--r--  1 root  wheel   149 Sep 19 03:15 /etc/auto_home
-rw-r--r--  1 root  wheel   233 Mar  8 17:47 /etc/auto_master
-rw-------  1 root  wheel   203 Mar  8 21:32 /etc/auto_qnap
-rw-r--r--  1 root  wheel  1935 Sep 19 03:15 /etc/autofs.conf

Now let's take a look at auto_master, notice the last line I added

adil-imac-1:~ adil$ cat /etc/auto_master
# Automounter master map

+auto_master  # Use directory service
/net   -hosts  -nobrowse,hidefromfinder,nosuid
/home   auto_home -nobrowse,hidefromfinder
/Network/Servers -fstab
/-   -static
/-   auto_qnap

And here is what /etc/auto_qnap look like:

adil-imac-1:~ adil$ sudo cat /etc/auto_qnap

/opt/mnt/myshare -fstype=afp afp://MyUser:MyPassword@MyServerIP/MyShare
/opt/mnt/public  -fstype=afp afp://

My initial thought was that I would use /Volumes to mount the folders, but that's really a folder Mac uses for dynamically mounting everything and auto-unmounts them. It's more like a temp directory. So I decided to use a folder more common in linux distributions /opt/mnt, which did not exist on my system of course, so I created it:

sudo mkdir -p /opt/mnt

then I created the auto_qnap file and changed its permissions to be read/writeable by root only, as it might need to contain password to connect to certain network shares.

sudo touch /etc/auto_qnap
sudo chmod 600 /etc/auto_qnap

The format for AFP and SMB are similar:

/Local/Mount/Folder   -fstype=afp    afp://MyUser:MyPassword@MyServerIP/MyShare
/Local/Mount/Folder   -fstype=smb    ://MyUser:MyPassword@MyServerIP/MyShare

I used IP address as it is static, but you could use FQDN of your Network Server. Once this is all done, you can run the following command to clear the cache and verbosely execute the mount command:

sudo automount -vc

I then created a symlink to the new mount points and put them in the Finder Sidebar:

ln -s ~/Pictures/PicsOnNAS /opt/mnt/public/pictures

Using this setup, I could now tell Flickr Uploader Mac Client to watch ~/Pictures/PicsOnNAS folder, and automatically upload pictures when I add a new ones there.

There you have it. It's not as easy as it is for Windows which automatically detects connection state of the mapped network drives, but close enough. Enjoy!

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