After several problems with the manual installation of Java JRE for embedded and CrashPlan 3.0.3 for Linux I finally gathered all informations to apply QPKG packages for proper installation on various QNAP systems (tried it on my QNAP TS-410 Turbo NAS in first instance).

Here is a quick step installation:

QNAP ARM CPU (x10 / x12 / x19)

Java Runtime Environment installation
- Download Java JRE for ARMv5 Linux – Headless (Early Access) EABI, glibc 2.5, Soft Float, Little Endian – you need to enter some data there to receive the download link (sorry cannot provide a direct download link as this is considered to be illegal)
- Copy file (name should look like ejre-1_6_0_25-fcs-b06-linux-arm-sflt-eabi-headless-14_apr_2011.tar.gz) to the Public folder on your NAS
- Download QNAP ARM Java package
- Unzip and install QPKG
- Enable JRE in QPKG manager

CrashPlan installation
- Download QNAP ARM CrashPlan package
- Install QPKG
- Enable CrashPlan in QPKG manager

QNAP x86 CPU (x9 without x19)

Java Runtime Environment installation
- Download QNAP x86 Java package
- Install QPKG
- Enable JRE in QPKG manager

CrashPlan installation
- Download QNAP x86 CrashPlan package
- Install QPKG
- Enable CrashPlan in QPKG manager

GUI access from a diffrent machine (e.g. Windows 7 box)

Configuration on QNAP NAS
- Disable CrashPlan in QPKG manager
- Edit /share/MD0_DATA/.qpkg/CrashPlan/conf/my.service.xml and replace
<serviceHost>127.0.0.1</serviceHost>
with
<serviceHost>0.0.0.0</serviceHost>
- Enable CrashPlan in QPKG manager

GUI installation on Windows machine (same configuration as for Linux GUI)
- Download CrashPlan client
- Install CrashPlan on Windows machine
- Go to Control Panel -> Services -> Look for CrashPlan Service (German: Systemsteuerung -> Dienste -> CrashPlan)
- Stop CrashPlan service
- Edit properties of CrashPlan service and set to manual start up (German: manuelles Starten)
- Edit C:Program FilesCrashPlanconfui.properties (maybe locatd in different folder) and replace
#serviceHost=127.0.0.1
with
serviceHost=...
Best is to use your NAS IP address – but the hostname should work as well
- Start CrashPlan – it should connect to your NAS (you will see your NAS name appearing there as source for backup)
- You may also remove the CrashPlan Tray from your Autostart folder because it will not work for a remote machine (if someone got a solution for this issue, feel free to post it!)

NOTE – This way of setting up CrashPlan on an ARM QNAP system with very low memory (256MB) proved to be better than the manual setup I did before. There were lots of memory problems and instability.

SOURCES – The following QNAP forum sources are best if you want to check for updates of the QPKG packages:
Java JRE QPKG – http://www.turbonas.com/phpBB3/viewtopic.php?f=18&t=870
CrashPlan QPKG – http://forum.qnap.com/viewtopic.php?f=227&t=39078

If you have any questions concerning manual installations of Sun / Oracle JRE for embedded systems on ARM or similar, please post a comment. Same goes for Crashplan installation on various Linux systems.