Error after (trying to) upgrading Raspberry Pi 1 from Wheezy to Jessie

Question

I've tried to upgrade my Pi from Wheezy to Jessie, so that I could get most recent versions of some applications and get the Pi up to date.

To accomplish the upgrade, I read over these sites:

https://www.raspberrypi.org/blog/raspbian-jessie-is-here/

And especially followed these instructions.

I'm brave enough to perform actions like these, but only as I don't have critical data stored there (well, actually I don't want lose any of the webpages and some apache configurations I own there).

Now, I can't install apps through console and nor fully complete the upgrade. See what happens when I type sudo dpkg --configure -a:

jins@raspberrypi /var/www $ sudo dpkg --configure -a
Configurando systemd (215-17+deb8u4) ...
addgroup: El grupo `systemd-journal' ya existe como grupo del sistema.     Saliendo.
groupadd: existing lock file /etc/gshadow.lock without a PID
groupadd: no se pudo bloquear /etc/gshadow, inténtelo de nuevo.
adduser: `/usr/sbin/groupadd -g 118 systemd-timesync' devolvió el código de error 10. Saliendo.
dpkg: error al procesar el paquete systemd (--configure):
 el subproceso instalado el script post-installation devolvió el código de     salida de error 1
Se encontraron errores al procesar:
 systemd

Is it possible to give a solution to my problem or do I have to backup my data and do a fresh install?

Answer 1

The Foundation do not support upgrade from Wheezy to Jessie. There are good reasons for this.

It is not impossible (and many have succeeded) - Apple and Microsoft both do similar, but they have much more controlled environments. Linux allows users much more flexibility which would multiply any compatibility issues.

The Foundation also lacks the massive engineering teams and resources to support upgrade, and chooses to use its limited resources in other areas.

If you choose to try an upgrade you need to have the requisite skills to perform your own fault finding. Time and effort which would be better employed in backing up your user data and restoring to a fresh install.