Dual-booting and change-rooting—lots of fun on the Acer C7!
The Acer C7 caught my attention when my wife and I determined we could no longer share our single Linux Mint laptop. My wife was frequently squinting at her cell phone's Internet browser, fighting my four-year-old daughter to use our Nexus 10 tablet, or struggling to remove my eight-year-old son from his Ubuntu laptop when I needed to use our shared laptop for school or work. I initially was drawn to the Acer because of its low $199 price. However, the C7's upgrade-ability really impressed me. So, I bought one, model C710-2847, in January 2013 at a local Best Buy along with a $25 4GB DDR 1300 memory module just in case the laptop's out-of-the-box performance was not adequate.
The 1.4kg Acer C7 laptop has a dual-core 1.1GHz Intel Celeron 847, 2GB DDR3 SDRAM, 5400 RPM 320GB hard drive and 4-cell battery. The screen, keyboard and touchpad are definitely sufficient for my wife to browse the Internet and read e-mail. The 11.6" glossy screen is nicely bright at 200 nit and easily viewed indoors. Rounding out the periphery hardware, the C7 has an SD/MMC media card reader, 1.3-megapixel Webcam, microphone, three USB 2.0 ports, VGA output and HDMI port.
The C7 uses the Chrome operating system, which is a lightweight operating system optimized for Web browsing. Do not confuse ChromeOS with the open-source Chromium operating system. ChromeOS began from Ubuntu Linux in 2009 with a contracted engineering service from Canonical. A year later, Google switched to Gentoo Linux. Today, ChromeOS is not based on any Linux distribution and is released by Google only for official devices. However, the source code is available through the Chromium OS project and can be installed on potentially any device.
ChromeOS provides a specialized debug terminal via the Chrome browser. Press Ctl-Alt-T, and a terminal will open with “Welcome to crosh, type 'help' for a list of commands.” Type help to list seven commands including the always useful top and ssh commands. Enter help_advanced to produce a longer list of mostly network-related commands, such as network_diag, which performs a suite of network diagnostics.
Acer released the original C7 in November 2012 and then updated it in March 2013. The updated C7 has only two changes from the previous version. RAM has been doubled to 4GB, and the battery is upgraded to 6 cells. The RAM is perhaps a worthy change, but the larger battery noticeably protrudes from the laptop's bottom. The price also increased to $279. The increased price is questionable, since the original C7 can be upgraded easily. Common upgrades are memory, hard drive, battery and operating system.
The C7 comes with one 2GB memory module installed in one slot and another empty slot. Maximum memory size available for the C7 is 8GB, allowing a total of 16GB. Memory may seem like a necessary upgrade, as the C7 does not use swap space. However, you can enable swap by opening the crosh terminal, typing swap enable and rebooting. A warning will appear in crosh stating that swap is an experimental feature and system instability may occur. Once rebooted, type swap status to verify the change. You should see /dev/zram0 listed under Filename with a size of 2932924 megabytes. Typing swap disable and rebooting will turn swap off.
However, based on my trials, the installed 2GB is sufficient, and swap does not need to be enabled. I opened ten tabs, some with a Linux Journal video running, a Netflix movie showing and a YouTube video playing, among several other static pages, and I still was able to play Angry Birds without issue. Moving between tabs also was seamless, and content was uninterrupted. I soon realized the extra 4GB memory I purchased was not needed. Unfortunately, Best Buy's return policy was 15 days, which surprised me because I expected 30 days. So, I installed the additional memory. I took off the C7's bottom plate and inserted the memory module. I verified the install by typing chrome://system in the Chrome address bar and then clicking Expand next to meminfo.
The existing hard drive can be updated with a solid-state drive (SSD), but there are trade-offs. You will give up a lot of storage space unless you purchase a large SSD, which can be expensive. Even the smaller SSDs are not cheap. The extra storage space may be handy if dual-booting the laptop with a Linux distribution. On the other hand, SSDs are lighter and probably more reliable than a traditional drive in a laptop. Don't expect all SSDs to perform spectacularly, because the C7 motherboard supports only SATA II 3GB/sec. An SSD probably would improve boot speed, but boot time is already a quick 17 seconds. Also, an SSD probably wouldn't produce much performance improvement, because the C7 does not use swap space, and the upgrade to 6GB of RAM negated the need for swap space. Thus, I did not pursue the SSD upgrade.
Two items to keep in mind if you decide to upgrade: pick an SSD that is 7mm tall because that is the height of available space for the hard drive, and pick one that supports LBA-48. According to some Web posts, the C7 requires a 48-bit Logical Block Addressing (LBA) scheme. The LBA specifies the location of data blocks on storage devices. However, upgrading the hard drive may be a moot point if you haven't already purchased an Acer C7. Best Buy now offers the Acer C7 at the same $199 price with a 16GB SSD.
I decided to skip the battery upgrade. The original 4-cell battery (2500mAh 37Wh) provides about three and a half hours of juice, which is plenty of time for intermittent use around the house, browsing the Internet and checking e-mail. People more disconnected from a power source may want to purchase a 6-cell battery. However, more powerful batteries can have form factors that counter the C7's slim dimensions.
Before upgrading the operating system, it is important to create a recovery image. Acer C7 recovery images are available from Google for download via Windows, Mac and Linux. A recovery image also can be created on the C7. Type “chrome://imageburner” in the C7 Chrome browser address bar to access the Image Burner tool. The tool requests 1) a 4GB or larger USB Flash drive or SD card be inserted and 2) acknowledgment that data on the C7 will be erased. These are the only two steps before the image is burned, which takes about eight minutes. Hold down Esc-F3, and tap the Power button to enter Recovery Mode.
Recovery Mode also provides entry to Developer Mode, which can be used to access system files and create a custom ChromeOS via a Bourne shell. Enter Recovery Mode first, and then press Ctl-D to enable Developer Mode. After the ChromeOS comes up, press Ctl-Alt-F2 to access the shell and Ctl-Alt-F1 to switch to the ChromeOS graphical user interface. Note, the C7 will not detect keystrokes while using the shell, so power management will dim and, eventually, turn off the screen. There are methods to disable/tweak power management, but my preference for turning the screen back on has been to switch to the GUI, press a key, and then switch back to the shell.
While in Developer Mode, an “OS verification is OFF” warning screen appears each time the laptop is restarted. Press the spacebar when the warning screen appears to exit Developer Mode and return to Normal Mode.
My time in the shell has been spent installing different Linux distributions, such as Ubuntu. The first approach I tried was dual-booting Ubuntu from a USB Flash drive using ChrUbuntu 12.04. Jay Lee created ChrUbuntu for the first Cr-48 Chromebook in 2010, and since then he has expanded this special build of Ubuntu 12.04 to other Chromebooks. Unfortunately, it has not been optimized for the Acer C7 yet. I still decided to give it a try. I entered Developer Mode and after about 45 minutes had ChrUbuntu installed on an 8GB USB drive. Ubuntu worked very well, but failed to resume correctly after going to sleep. In many cases, the user interface would come back up and screen pointer would move, but the icons would not work. I jumped to a terminal and also found, using top, that polkitd and dbus-daemon were continually consuming >50% of the CPU, and console-kit-daemon and NetworkManager were consuming around 10–15% each. Further, I noticed the C7 ran very hot, and the fan was quite audible.
Next, I tried to install ChrUbuntu 12.04 on the C7's 320GB hard drive alongside ChromeOS. The install went well, but it still had the same CPU issues and ran hot. Jay Lee released a new ChrUbuntu script on May 31, 2013, that installs any flavor and version of Ubuntu, such as Xubuntu 12.04. I chose the standard install, which is Ubuntu 13.04. Unfortunately, I encountered the same CPU and heat issues as before. I provided this feedback to Jay Lee as requested on his blog.
I entered Recovery Mode and inserted the recovery media to restore the C7's original condition. Note that all data on the C7 will be erased, and there is no warning. However, Google-synced data, such as Bookmarks, will not be affected.
Then I tried to install ubermix. The ubermix distribution is built by educators for students and teachers. It has received a lot of positive press and recognition from the education community. The current version uses Ubuntu 12.04, Linux kernel 3.4.0 and GNOME 3.4.2 with a streamlined user interface that is probably too simple for Linux power users. I downloaded the ubermix install key image to my Linux Mint laptop, placed it on a USB thumbdrive and copied it to the Acer C7 via Developer Mode. Install was very similar to ChrUbuntu, because you run the same install script twice, once to repartition the hard drive and second to install the new operating system. The two-step process took about 20 minutes. Happily, everything worked well except some special keys, such as brightness and sound. I followed the simple instructions on the Ubermix on Chromebooks wiki to resolve those issues. Although the ubermix user interface is fairly basic, it does have easy access to more advanced features like system settings, terminal window and so on. The single issue I found with ubermix was that only 2GB of the installed 6GB memory was recognized, but system performance was still very good.
I reloaded the factory ChromeOS via Recovery Mode and tried to install ChRomium Os UbunTu chrOot enviroNment also known as Crouton. It was created by David Schneider and uses a chroot operation to run Ubuntu on ChromeOS devices. In theory, the chroot approach should work for any Linux distribution because they will all run by using ChromeOS—that is, the distribution is not booted by itself, but rather runs within ChromeOS. Thereby, reboot is not needed to switch between Ubuntu and ChromeOS. I downloaded Crouton, opened a crosh terminal via Ctrl-Alt-T, typed shell, and ran this command to install Xubuntu:
sudo sh -e ~/Downloads/crouton - xfce
The install completed in about 45 minutes. Entering sudo startxfce4 in the crosh shell started Xubuntu, and everything worked well. I pressed Ctrl-Alt-F1 to get back to ChromeOS. Interestingly, I could not press Ctrl-Alt-F2 to get back to Xubuntu. I had to press Ctrl-Alt-F2, which brought up Developer Mode, and then press Ctrl-Alt-F3 to get back to Xubuntu. Other distributions are available with Crouton, such as Kubuntu, Lubuntu, Xubuntu and the standard Ubuntu. Type sudo sh -e ~/Downloads/crouton -t help to see available target distributions and correct nomenclature for downloading.
This journey to the Acer C7 Chromebook began when my wife and I determined we could no longer share our single Linux Mint laptop. Now we have determined we can no longer share our single Chromebook! It is a fantastic laptop that performs great for basic tasks. You can upgrade the C7's hardware, but it's not really necessary. You also can play around with the operating system, which is a lot of fun. There are some real opportunities to learn and grow Linux on the C7 with a custom ChromeOS, ChrUbuntu, ubermix and Crouton. Best of all, after playing around, the C7 can be restored to factory condition in about ten minutes, and everything will be synced back to your configuration automatically.