error

installArchives() failed: debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable
debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable
debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable
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(Reading database ... 189527 files and directories currently installed.)
Unpacking postfix (from .../postfix_2.8.2-1ubuntu2.1_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_2.8.2-1ubuntu2.1_i386.deb (--unpack):
 subprocess new pre-installation script returned error exit status 1
No apport report written because MaxReports is reached already
Errors were encountered while processing:
 /var/cache/apt/archives/postfix_2.8.2-1ubuntu2.1_i386.deb
Setting up man-db (2.5.9-4) ...
debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable
dpkg: error processing man-db (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mailutils:
 mailutils depends on default-mta | mail-transport-agent; however:
  Package default-mta is not installed.
  Package mail-transport-agent is not installed.
dpkg: error processing mailutils (--configure):
 dependency problems - leaving unconfigured