Root without losing data

Have you already unlocked the bootloader?

Unlocking the bootloader is what wipes user data. Once the bootloader is unlocked, one may root without losing any user data.

The best option on a Nexus device is to unlock the bootloader before setting up the device, so there isn't any user data to get wiped.
 
If you unlocked your bootloader already then no, no reason or should erase your data. If you haven't unlocked the bootloader then yes, your data will be wiped.

Posted via the Android Central App
 
Thanks.... Is it possible to back up my nexus 6 unlock bootloader and put everything back on?