ADB backup is not working

I just tried to make a backup from my Nexus 5 (before installing CM 11) It is unlocked but not rooted. On PC side I'm working with Ubuntu 13.10.

When I type

adb backup –all -apk -nosystem –f /data/Nexus5Backup/backup_17042014.abk

then my phone asks me if I want to backup and I confirm. But the terminal in Ubuntu immediately returns to prompt (~$) and my phone says the backup is complete.

When I type

adb backup –all -apk -shared -nosystem –f /data/Nexus5Backup/backup_17042014.abk

and also confirm that I want to backup then the terminal hangs at

Now unlock your device and confirm the backup operation.

The phone is displaying "shared storage".

But the weirdest thing is that in both cases the backup file (/data/Nexus5Backup/backup_17042014.abk) is never being generated.

How can I do a full backup? I already did backups in the past and they worked. Is this a bug in my Android version (4.4.2 KitKat)? And is there a workaround?

Answer

I asked this question some time ago and as I weren't able to fix it, I simply forgot about it. However as adb backup seems to work again for me and because it may be an issue for others I'll post here, what has changed since last time.

Actually an update fixed that issue. So I guess it was a bug. I can't determine which version it was but everything works fine at least since the versions of Ubuntu and adb you can see below. If the tip of matt wilkie doesn't work out for you and if you are using an older version of Ubuntu and/or adb I strongly recommend an update.

$ adb version
Android Debug Bridge version 1.0.31
$ lsb_release -d
Description:    Ubuntu 14.04.2 LTS