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{mospagebreak toctitle= Introduction, Setting Up}


CTERA CloudPlug
At a Glance
Product CTERA Cloudplug
Summary Tiny, powerful, bring-your-own external drive NAS with "cloud" storage
Pros •Good Performance
•Nice User Interface
•Low Power
•Small footprint
•eSATA support
Cons • About twice the cost of competing products

Ever since I got my hands on a NSLU2, I've been a sucker for little Network Attached Storage (NAS) devices. Why fire up a big, noisy, power-hungry file-server when a tiny, silent 3.5 W NSLU2 will do the trick? I found a lot of uses for my NSLU2, but there was a downside. Running at 133Mhz with only 32 MB of RAM, the NSLU2 wasn't the fastest NAS around. And now, five years later, it's also out of production without much to replace it when you're in the market for a silent NAS with small form-factor and low power draw.

But things have changed. In this review, I'll check out the CloudPlug from CTERA. Hardware-wise, the CloudPlug is a tiny bring-your-own external drive NAS with all the silent, low power-draw goodness of the NSLU2 while adding eSATA support, Gigabit Ethernet, a 1.2 GHz processor and 512 MB of RAM. As far as software functionality, the CloudPlug performs the standard role of a NAS while automatically encrypting and copying your data to a "cloud" server for additional protection. And you get all this in a device that draws as much power as a nightlight while looking more like a wall-wart than a NAS.

With rough dimensions of 4" x 3" x 2" inches and power-prongs on the back, you'd be forgiven for mistaking the CloudPlug as a power-brick instead of a NAS. Figure 1 shows the bottom of the device where you can see the Gigabit Ethernet, eSATA, USB 2.0 connectors.

Bottom of the CloudPlug

Figure 1: Bottom of the CloudPlug

The USB and eSATA ports can be used simultaneously or if you really want to load it up with disks, you can add a USB hub. In use, the device is completely silent since it has no fan. And it doesn't draw much power either, which I measured at a measly 4 W.

Getting the CloudPlug onto your network is as easy as connecting a drive and a network connection and plugging it in. One of the key features of the CloudPlug is storage to the "cloud". So if you want to take advantage of this, you'll also need to set up an online account at the CTERA portal before starting the local configuration. Figure 2 shows the initial sign-up form on the CTERA web site.

Setting up a cloud-storage account at CTERA

Figure 2: Setting up a cloud-storage account at CTERA

Setting Up

Once you're set up at CTERA, you start configuring the local device. Just remember to keep track of which account is which, because the administration account you set up for the local system isn't the same as the account that you set up on the CTERA website.

Like most NASes, configuration is accomplished via your web browser. The CloudPlug announces itself on the network both via both UPnP and Bonjour, so it should be fairly easy for most modern operating systems to find it on the LAN. Figure 3 shows the local administration account login prompt the first time I connected to it with my browser.

Admin login prompt

Figure 3: Admin login prompt

The basic setup of the device is pretty much as expected. A "wizard" walks you through setting up an administration account, the network configuration, the time zone, the machine name, etc. When it comes time to connect your external disk, you'll need to make some choices about disk format. The CloudPlug supports formats of FAT32, NTFS and EXT3. If your external drive is already in a supported format, you'll see an "already in use" message (Figure 4).

Configuring a drive

Figure 4: Configuring a drive

You can leave your drive in a supported format, but CTERA advises for maximum performance, you'll want to use the "Format" option, which will put the drive into EXT3 format (and erase any existing data in the process). Where setup begins to show a difference from a standard NAS is when you tie the local device to the CTERA portal account set up earlier (Figure 5).

Tying the local device to the CTERA portal account

Figure 5: Tying the local device to the CTERA portal account

Setting Up - more

As you saw in Figure 5, connecting to a CTERA portal account is optional. But without it, you'll be unable to take advantage of one of the main features of the CloudPlug: "cloud" storage. The deal is that you get 10 GB of storage on CTERA's servers for a year bundled with the device. But once your first year is up, you pay the following rates:

  • 10 GB for $9.95/month
  • 25 GB for $19.95/month
  • 50 GB for $29.95/month
  • 100 GB for $49.95/month
  • 200 GB for $99.95/month

A quick survey of cloud storage providers shows that online storage prices are all over the map, and several companies have different rates for commercial vs. personal usage. But CTERA's rates generally seem in-line with other full-featured, encrypted storage companies. But when you're thinking about cloud storage, you can't help but think of the black eye that Microsoft give the concept recently and this is a real concern.

Regardless of the competency of your storage vendor, who's to say which storage company will even be around when you go to retrieve your data? That's why for me, this type of storage would only be a secondary backup. I'd like the NAS device to back data up locally, and then automatically encrypt and back it up to the cloud. Fortunately, the CloudPlug supports this model of backup and that's how I set it up.

Figure 6 shows the entry for a passphrase to go along with the 256-bit AES encryption key that's used to encrypt the data before it is copied to CTERA's servers. Note the warning regarding the passphrase. If you lose this key, your data cannot be retrieved.

Setting up a passphrase

Figure 6: Setting up a passphrase

Once you have the device connected to your online account, you'll configure the local directories that will get backed up. Figure 7 shows the setup screen where I've selected a couple of directories on my USB key for backup to CTERA's servers.

Selecting folders for backup

Figure 7: Selecting folders for backup

Initially, you have no options regarding what kind of files to back up and what to skip. But you can modify this later in the detailed configuration menus. The same is true for the backup schedule, which by default occurs on a daily basis. Directory selection is the last stop in the wizard so once it's done you can either start using the CloudPlug or jump into more configuration via the administration menus. Note that administration can be done using either an HTTP or a secure HTTPS connection.

Feature Walkthrough

Figure 8 shows the home screen of the administration menus.

Home screen

Figure 8: Home screen

In general, I found the administration screens very well done, attractive and complete as modern web-apps continue to blur the line between the desktop and the browser. Some of the administrative screens did seem to use a bit of CPU and would cause my laptop fan to kick on when I lingered on them. Figure 9 shows one such intensive display where the process of my backup to the CTERA servers is shown.

Backup Status

Figure 9: Backup Status

I'll also note at this point, that the backup to the CTERA servers seemed to be slower than I would have expected. My Internet upload speed is around 768 Kbps or 96 KB/s and I tried backing up 1.8 GB to CTERA's servers. At a full speed of 96 KB/s, this should take around 5.2 hours. But after 8 or so hours overnight, my first backup was only 73% done.

Fortunately, CTERA uses an incremental backup scheme, so your first backup will be the most painful. If you do find that the backup is saturating your network, there's a setting that allows you to throttle the transfer either during certain hours or all of the time (Figure 10).

Throttling transfer speed

Figure 10: Throttling transfer speed

Even though the backup seemed to be slow, the CloudPlug device itself hardly seemed strained as the backup was underway. Figure 11 shows a nice overview screen where you can see stats regarding disks, CPU, backups, etc.

CloudPlug Dashboard

Figure 11: CloudPlug Dashboard

In this display, you can see that while the backup is in progress, the CPU is almost idle and there's plenty of available RAM. There are a lot of nice features available through the administrative menus such as user and group creation, detailed logging, etc, but I don't have room to detail them all so I'll touch on some of the more interesting ones.


In the CTERA admin menus, "Backup" refers to the Cloud storage and "Synchronization" refers to local backup. For Synchronization, CloudPlug has the ability to do bi-directional synchronization. So you can either copy from other systems on your network, or you can push data to them. You can also set up multiple synchronizations jobs, all with different schedules, destinations, protocols, etc. Figure 12 shows the protocol selection when I was setting up one synchronization job.

Advanced synchronization setup

Figure 12: Advanced synchronization setup

Typically, this is where you would set up and schedule backups from your local network machines that would work in conjunction with the offsite Cloud backup jobs defined in the CloudPlug menus. But note that you could also use this menu to define your own offsite backup, with the downside being that the data would not get encrypted on the destination server and your data won't be available through CTERA's portal.

Online Portal

There are a number of nice features available through the online portal. Once you log in and supply your passphrase, you can access all your backed up data from anywhere you have an Internet connection. Figure 13 shows the main menu from the online portal.

CTERA Portal main menu

Figure 13: CTERA Portal main menu

Just like the local interface, the portal has a nice feature set and is fairly responsive. You can change account settings, check out the status of your backups, check logs for issues, etc. Figure 14 shows a nice file-browsing capability on the portal that allows you to view your files, download them to your local system, or restore them back to the CloudPlug directory.

Browsing files from the Portal

Figure 14: Browsing files from the Portal

The integration between the Portal and your local CloudPlug device is very tight. The online portal will even report on local CloudPlug CPU usage, network settings, login activity, etc. But like the local admin page, the portal pages could put a significant load on my CPU, pushing my Firefox browser pretty much to the max and kicking on my fan.

Moving back to the local configuration screens, you might also want to enable FTP access to your CloudPlug. Figure 15 shows the FTP setup screen where you can opt for anonymous access, encrypted access, set some throttling parameters, etc.

FTP setup

Figure 15: FTP setup

As you can see, the configuration is fairly complete with the exception of allowing you to change the port that the FTP server runs on. And speaking of ports, a quick port scan of the CloudPlug showed that there was also support for accessing shares via standard and secure webdav, although there didn't seem to be any configuration menus or info in the user's guide related to use of this protocol. Another thing I didn't notice in any of the menus was a feature to allow you to set the spin-down time on your external drives. Most of the time my NASes sit idle, so it's nice to be able to tell the drives to spin down when they haven't been accessed for a while.


So, since this little box has a lot more horsepower than usually found in this sort of device, what's the performance like? It's surprisingly good, especially when using a EXT3-formatted eSATA drive. We tested the CloudPlug using our standard Vista SP1 filecopy test, which copies a 4.35 GB ripped DVD test folder from a RAID 0 volume on our standard NAS testbed to and from the NAS under test.

Figure 16 shows a performance summary when an Iomega UltraMax Pro Desktop Hard Drive configured in RAID 0 is attached via USB 2.0.

usb tests

Figure 16: CloudPlug Performance using a USB drive

As you can see, CTERA's advice regarding using an EXT3-formatted disk proves true. Even though FAT32 slightly outperforms EXT3 in our read test, in our write test EXT3 roughly doubles the performance of FAT32. In both cases, NTFS falls far behind. Basically, the CloudPlug has enough processing power to max out the USB 2.0 connection in both directions for EXT3 format and for FAT32 reads.

And what kind of a speed boost will you get when using an eSATA drive? Figure 17 shows the result.

eSATA tests

Figure 17: CloudPlug Performance using a eSATA drive

The advice for using EXT3 still proves true for eSATA, and you'll get a substantial speed boost as well. In reading, you'll get nearly twice the EXT3 performance as compared to USB. So the lesson is clear. If you need the speed, go with eSATA and EXT3.

Under the Covers

When I first saw this little box, its origin was obvious. The power behind it and several other variations, such as CloudEngines' PogoPlug and Seagate's FreeAgent DockStar is Marvell's Plug Computing platform. Marvell documents the components used in the platform as a Kirkwood series System On A Chip with an embedded Sheeva CPU core running at 1.2 GHz and 512 MB of RAM.

Figure 18 shows the main board of the CloudPlug after I removed the case and pulled back the shielding.

main board
CloudPlug Main Board

Figure 18: CloudPlug Main Board

You can see the Marvell device that's at the heart of the device along with the flash, RAM and Marvell 88E1116R Gigabit Ethernet device.

It's also no secret that the OS running on the platform is Linux, since this is well documented by Marvell. You can pick up a "Development Kit" version of this platform at the Marvell site for $99, and with it you'll get command-line access, the ability to build your own Linux kernel and other components.

There's also a Sheevaplug Debian port that really gives you the ability to go where you want with this powerful little device. There are a couple of differences between the development hardware version and the CloudPlug. The development device doesn't have eSATA, but it does have a mini-USB with serial console and JTAG support to help with boot control. And also with the development kit, you'll be on your own for the user-interface.

As far as the CloudPlug, I tried hard to get command-line access, but CTERA has done a good job locking the product down. None of my standard manipulation of the web user-interface variables allowed me to break in. Kudos to CTERA for properly validating all input at both the JavaScript level and the server level.

I did find an undocumented Telnet server running on the CloudPlug, and it accepted my login credentials. But then it immediately kicked me out because my "home" directory wasn't defined. Along with the standard Telnet server, there was also one running on port 8000, which let me in. But instead of giving me a generic command-line, its usage was restricted to manipulation of system configuration variables. So, this little guy isn't all that "hacker friendly". But if that's what you are interested in, you'll likely be targeting the less-expensive development kit instead of the CloudPlug.

Closing Thoughts

CTERA did a nice job with this product. The user interface was very well done, and the cloud-storage features worked as advertised. For my own usage, I typically end up automatically backing up locally and then manually copying my important data out to an Internet server. Any time you have a manual step in the process, you're adding a risk that you'll fall behind, forget files, etc. This box would alleviate that while also adding encryption.

For small-office or home use, the CloudPlug has surprisingly fast performance, low power consumption, a tiny footprint and is completely silent (except for the drives you'll attach).

The CloudPlug does lack some of the "kitchen sink" server features that other NAS manufacturers are providing, such as print, web, media, photo, database, etc. But CTERA's primary focus is on file serving and backup and that they do very well.

The cost of the CloudPlug is around $200, which includes 10 GB of storage for a year. While this is twice what you'll pay for a PogoPlug or Seagate FreeAgent DockStar, neither can come near it in terms of performance because they both lack an eSATA port. Still, CTERA might sell more CloudPlugs if they got the price closer to the $99 of its competition.

So if you're looking for a way to get your eSATA or USB drives onto your network, with the option for offsite "cloud" backup, CTERA's CloudPlug deserves a close look.

This article originally appeared on SmallNetBuilder.