how to make adb backup for acer liquid A1 to my computer?

[Guest winlinwcn]

I was searching online for how I can I make a back up for Acer liquid A1 to my computer, I found it is possible using SDK.

I tried to make a backup using the following adb command:

adb backup -all -f C:\backup.ab

but i got this error

adb: unable to connect for backup

even though USB debugging is enabled , and adb devices recognizes my acer.

I am using CM7.2 (final improved by Ainilia )

is there any way to creat backup file, on my computer ?

Thanks in advance

[Guest Ma7moud]

adb backup works only on Android 4.0 and newer

try it on CM9

[Guest winlinwcn]

adb backup works only on Android 4.0 and newer

try it on CM9

Thanks for your reply, !!!

is there any good working CM9 rom for Acer A1, with (less than 50 seconds boot time, and all working features and without a swap partition required) ?