From DpkgTerminalLog
Unpacking postfix (from .../postfix_2.5.5-1.1_i386.deb) ... debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable dpkg: error processing /var/cache/apt/archives/postfix_2.5.5-1.1_i386.deb (--unpack): subprocess pre-installation script returned error exit status 1
This is an apt issue, described in bug #349469. I'm marking this a duplicate.
From DpkgTerminalLog
Unpacking postfix (from .../postfix_ 2.5.5-1. 1_i386. deb) ... debconf/ config. dat is locked by another process: Resource temporarily unavailable apt/archives/ postfix_ 2.5.5-1. 1_i386. deb (--unpack):
debconf: DbDriver "config": /var/cache/
dpkg: error processing /var/cache/
subprocess pre-installation script returned error exit status 1
This is an apt issue, described in bug #349469. I'm marking this a duplicate.