مشکل در نصب IBSng free

[why.darkness]

خب قدم اول من این کار رو انجام میدم


vps249108:~# apt-get install httpd postgresql postgresql-server postgresql-python php perl -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
Note, selecting apache2-mpm-prefork instead of httpd
apache2-mpm-prefork is already the newest version.
Package postgresql is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
postgresql-common postgresql-client-common
E: Package postgresql has no installation candidate
vps249108:~#


بعد ش


vps249108:~# apt-get install postgresql
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package postgresql is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
postgresql-common postgresql-client-common
E: Package postgresql has no installation candidate
vps249108:~#

این خطا رو میده اینجا !

---------- Post added at 11:55 AM ---------- Previous post was at 11:52 AM ----------

در حذف دیتابیس هم این مشکل رو دارم :

postgres@vps249108:~$ dropdb IBSng
dropdb: database removal failed: ERROR: database "IBSng" is being accessed by other users
postgres@vps249108:~$