Hello - first off - I want to indicate that I am not responsible if you inadvertently cause damage or harm to the Linux shell of your ReadyNAS system. These steps are only for the ReadyNAS Duo v2 and have been successfully accomplished on my own ReadyNAS Duo v2. It MAY also work on a ReadyNAS that runs an ARM chip but I can not speak to this.
As some of you may know or have come to figure out, the Duo v2, which runs the ARM chip, does not run the Skifta add on that allows you to shift your media to a remote location (such as a friend's DLNA capable device, your smart phone, or tablet). However, taking from previous experience I had getting the Skifta server to run on a WD MyBook box using SSH I adapted my approach for the Java Runtime Environment developed for the ARM chip.
1. Create a share folder under "Media" called "Skifta" 2. Download the Headless version of embedded Java for the ARMv5 chip: http://www.oracle.com/technetwork/java/embedded/downloads/javase/index.html 2a. You will need to sign up for an account in order to get the download - account is free but the website indicates that the Java is only for 90 days, although there is a step you can follow to reset the 90 period (that I will list later in the instructions) 2b. You will need to download "ARMv5 Linux - Headless" under the "Java SE for Embedded 7" heading 2c. Save the tar file to the Skifta share you created in step 1. 3. Download the Skifta install file from the Skifta website. You will need "Linux Installer without Java Runtime": http://www.skifta.com/download#home 3a. You will need to click "Need a different version" located under the big Download button in order to find the Linux versions of the file. 3b. Save the file to the Skifta share you created in step 1 and change the name of the file to "Skiftanorjre.bin". 4. You will need SSH in order to run the commands necessary to install both the Java runtime and the skifta install. At this time, the link for this download file is not noticeably available on the add ons page of the Netgear website but another helpful member (credit to "mdgm") put the link up: http://www.readynas.com/download/addons/arm/5.3/EnableRootSSH_1.0-arm.bin" 4a. This can be saved to your regular downloads folder on your computer.
Ok. So first thing you have to do is get SSH up and running since, unfortunately, beyond installing SSH, everything beyond that point is console based (i.e. no friendly GUI).
NOTE: Enabling SSH could void your warranty and leave you out of luck if you need assistance from Netgear. I've read this time and time again for different Linux based NAS manufacturers so just be aware of this fact before you proceed. DON'T BLAME ME! I'm just trying to help those out there that are willing to get their hands dirty to have the hardware they own work the way that suits them.
Installing SSH 1. Navigate to the Add Ons screen of the ReadyNas web-based dashboard. 2. Click on the little + icon in the upper right corner to provide the NAS with a new add on. 3. Click on the browse button and navigate to the folder where you saved the root image file from step 4 of the steps above. 4. Select the "EnableRootSSH_1.0-arm.bin" file and click OK. 5. Click OK on the little window that appears.
The add on should install and you should be advised that your system is going to reboot. Click OK to let it reboot now. You can use the Raidar utility to determine when the system is back up. You will need to wait until the volume has completely loaded back up before you can proceed to SSH.
Once all lights are green on Raidar, it is time to leave the beautiful world of GUI and start using console. My personal favorite SSH software is Putty, which can be downloaded here, assuming you don't already have an SSH client: http://the.earth.li/~sgtatham/putty/latest/x86/putty.exe
There is no install - just the executable - so you can save the EXE file to your desktop and double-click to start.
Putty SSH Instructions 1. Each time you start the program a Putty Configuration window will appear. Make sure that "Session" is selected in the left selection tree. Change the Connection Type radio button to SSH if it is not selected. Leave the Port as "22". In the Host Name field you can either type the name you gave your ReadyNAS or the IP address that your router's DHCP has assigned to the ReadyNAS (or the static IP you have assigned in your router). Note: If you do not know what this is or how to get it, please stop here and do not continue - you will likely cause damage to your NAS if you do not understand this step. 2. Click Open. The first time you access your NAS this way you will get a message from Putty - just hit "Yes" or "OK" to proceed. 3. Username is "root" (without quotes). 4. The password will be the same admin password that is used to access the web admin (Dashboard). 5. You will know you are in when you see something like "root@<ReadyNAS Name>" where <ReadyNAS Name> is the name you gave your ReadyNAS or IP Address of your ReadyNAS.
Before continuing - if you do not yet have a Skifta account, create one now as it will be needed during the skifta install: http://www.skifta.com/modal-register
Ok. The easy part is over - now it is time to get down to business. Installing the Embedded Java Runtime 1. Type "cd /media/Skifta" and hit Enter 2. Type "tar xzvf ejre-7u2-fcs-b13-linux-arm-sflt-headless-22_nov_2011.tar.gz" and hit Enter 2a. This essentially unzips the tar file that you downloaded 2c of the original set of instructions above. 2b. A new folder will be created in the Skifta subfolder called "ejre1.7.0_02" 3. Using Windows Explorer or similar explorer program (if you are running Linux or Mac) go to your ReadyNAS and navigate to this new folder that was created in the Skifta subfolder. Then go into the lib subfolder. Copy the arm subfolder and place this copy in a safe place (either on your nas or on your local machine). From what I read, this is what must be done so that when the 90 period is up you can just copy this copy over to the subfolder in the lib subfolder on your nas and that will reset the 90 day period. Though, I am skeptical of the need to even do this (I will repost in 90 days to let you all know if this is actually necessary). 4. Go back to SSH and type "export JRE_HOME=/media/Skifta/ejre1.7.0_02" and hit Enter
Installing and Running Skifta 1. Type "cd" and hit Enter 2. Type "./Skiftanojre.bin LAX_VM /media/Skifta/ejre1.7.0_02/bin/java" and hit Enter. 3. The install will begin and you will see messages about the GUI not being available and that it will start in console mode. Go through all the prompts of the install. When it prompts you to indicate the location you want to install type "/media/Skifta". 3a. I also recollect at one point is asking me a question and saying to just hit enter to use the default. For the life of me, I can not remember what this was but I do remember that I just used default - so if you see something similar, go with "Enter". 4. Again, it may ask you a few more questions to which I answered is "Y" to all (with exception to where it asks you for your Skifta username and password - you want to indicate that you do already have a skifta account and then enter the username and password you signed up with on the Skifta site earlier). 5. The install will begin and you will see a bunch of lines that look like [----------------------] which is basically the console version of a status bar. When I did my install, the install hung for a while about 3/4 of the way through the 2nd line of the "status bar". I would say about 5 minutes or so but give it a chance and it should completely install. EDITED 12/20/2011 6. Type "nohup /media/Skifta/ejre1.7.0_02/bin/java -jar /media/Skifta/Skifta.jar -start > /media/Skifta/log.txt &" and hit Enter 7. nohup runs the process in the background and the last part of the command diverts all output to a log.txt file in the Skifta share you created so that in case something goes wrong, you will have the logs available to you. 7a. The log file will increase in size over time so you will want to go in and delete the file every once in a while. The system should re-create the log file for you. 8. You can close SSH - you should be good to go.
NOTE: You will need to repeat steps 6 through 8 after each reboot of your ReadyNAS system. There is a way to alter the init script so that this happens automatically each time it restarts, but that is something I have not attempted, and thus I am not going to put instructions here. If anyone else is brave enough to try it and successfully accomplish the init script alteration, feel free to post here.
Good Luck to all. I tried to be as detailed and exact as possible. However, I wrote this about 3 hours after successfully completing the process myself. If you hit any snags, feel free to post with as much detail as possible. If you have to alter any of the steps to make it work, please share with the community so that everyone can benefit. I will not take offense if you need to change any of my steps (or you find a more efficient way of doing this).
FYI - A common problem is for the share folders for your media not to show any media in them or not show up at all. For some reason, when you create the share folders with Windows Explorer, ReadyDLNA does not pick them up. The way around this is to create the folder using the web-based dashboard utility for the ReadyNAS and then start adding your files to the folder. Doing it this way makes the ReadyDLNA server pick it up and then you can see your media on your DLNA devices and Skifta.
Just another helpful piece of info. Hopefully, a future firmware release from Netgear will resolve this issue.
With regard to your first question, I do not know because I have not tried it. I would think your firmware should having nothing to do with it since you are still running on a Debian LInux OS on an ARMv5 chip. It is the chipset that matters for the Java Runtime Environment.
As for uninstalling, I have not yet attempted this. Not long after I accomplished installing on the Duo, I decided to get the Ultra. The Ultra boasts better processing power and memory. In addition, the primary reason I purchased the NAS was for movies, music, pictures, etc. Once I found out that the Duo is only DLNA Ready but only the Ultra is DLNA Certified, it became clear why the Duo's DLNA capabilities are spotty/buggy. So I moved to the Ultra and use the Duo as a nightly backup repository (which has come in handy a few times when I have FUBAR'D my Ultra experimenting).