I recently purchased a personal network attached storage (NAS). It’s a 1.5TB external hard drive from Western Digital. It’s called – Western Digital 1.5 TB My Book World Edition II Hard Drive.  Thanks to my friend, Don, for telling me about this.
There are many good things about this product. Unfortunately, there are some bad things too. Let’s start with the good things.
The good things:
I purchased this from Amazon at US$319.  At this time, a standalone 500GB hard drive costs around $99. I thought this was impressive. It was the cheapest Linux-based NAS I could find out there.
2. Easy to setup.
It uses a web interface for setup and administration. Setting it up was as easy as setting up a wireless router. By default, it can do Windows-sharing type of access (CIFS/SMB). It also has this proprietary type of file access called MioNet (WDAnywhere), but I didn’t bother using it since I was only interested in using Samba and NFS. I actually disabled this hoping it would help speed up the machine.
3. It can do NFS.
If you’re going to use this with Unix, you would definitely want to have NFS access to this device. However, this is no longer available by default in the new firmware, 2.0.15+.  I had to install some nfs files manually (exportfs, rpc.*) to get this running. See my other post for details on how to set this up.
4. It’s a Linux machine.
It’s a small computer in itself and one of the compelling reasons I bought this was that it uses Linux. Therefore, in addition to disk storage, you can use it as a Linux machine with all the goodies like ssh, lighttpd, Perl, etc.
5. Quiet and cool.
Some reviews out there claim that this device is noisy. With two 750GB disks and a Linux machine in itself, I thought this was relatively more quiet than running your own Samba/NFS server on a desktop PC. It uses a small and low-power CPU (ARM926EJ). 
6. Plenty of Linux support.
You don’t want to be alone hacking this device. There are plenty of people already hacking this NAS. [4,5]
Now the bad things:
1. It’s slow!
I don’t understand what went wrong here because this NAS has a Gigabit ethernet and according to the specs, the drive speed is 7200RPM. However, I can only get a maximum of 7MB/sec of write speed. Note that this is through local access on the machine itself and not even across the network. I use the Unix command dd to measure write speed.
dd if=/dev/zero of=/tmp/x bs=1024 count=10240
10240+0 records in
10240+0 records out
10485760 bytes (10 MB) copied, 1.6501 seconds, 6.4 MB/s
I suspected that this is due to the CPU or IO of the machine. Therefore, even with a Gigabit ethernet and 7200 RPM drives, I doubt you can get it any faster than 7MB/s if the bottleneck is the CPU or IO.
I tested NFS write speed on a 100Mb/sec network and I can only get a maximum of 5 MB/sec.
2. NFS is disabled.
NFS used to be installed by default. All you need to do to use it was enable it. However, I learned that they removed this in versions v2.00.15 and later.  I had to install NFS files manually to get it up and running. I wonder why WD had to remove this. It appears that they don’t want users to be using this NAS with NFS. In addition to not supporting Linux access, WD also makes sure that it’s not there in case you’d want to use it.
3. Certain types of files cannot be shared
The software WDAnywhere restricts certain types of files from being shared. According to WD website, “Due to unverifiable media license authentication, the following file types cannot be shared…”  What this means is that you cannot share media files like mp3 or mpeg files even if they are your own personal audio or movie files.
I don’t have this problem with Samba and NFS. This has nothing to do with technology so I don’t want to comment about it. But I thought I find this feature amusing.
It’s probably a good idea to disable access to your network’s Internet gateway. If you only want to access this device on your intranet (LAN), there is no need to have it access your gateway and then the Internet. This makes it more safe in case you accidentally open up your router to your machines on the local network. This also prevents viruses or trojans from running on this device and contacting someone out there on the Internet, although highly unlikely because it uses Linux.
 WD FAQ – What files cannot be shared by WD Anywhere Access?