Debian: There is no public key available for the following k

root@mfus1006:~# apt-get install debian-keyring debian-archive-keyring

Reading package lists... Done

Building dependency tree

Reading state information... Done

debian-keyring is already the newest version.

The following packages will be upgraded:

  debian-archive-keyring

1 upgraded, 0 newly installed, 0 to remove and 79 not upgraded.

Need to get 60.7 kB of archives.

After this operation, 26.6 kB of additional disk space will be used.

Do you want to continue [Y/n]? y 这里需要回答 y 确定

Get:1 http://ftp.debian.org/debian/ wheezy/main debian-archive-keyring all 2014.3~deb7u1 [60.7 kB]

Fetched 60.7 kB in 0s (101 kB/s)

(Reading database ... 30582 files and directories currently installed.)

Preparing to replace debian-archive-keyring 2012.4 (using .../debian-archive-keyring_2014.3~deb7u1_all.deb) ...

Unpacking replacement debian-archive-keyring ...

Setting up debian-archive-keyring (2014.3~deb7u1) ...

命令二：

root@mfus1006:~# apt-key update

gpg: key B98321F9: "Squeeze Stable Release Key <debian-release@lists.debian.org>" not changed

gpg: key 473041FA: "Debian Archive Automatic Signing Key (6.0/squeeze) <ftpmaster@debian.org>" not changed

gpg: key 65FFB764: "Wheezy Stable Release Key <debian-release@lists.debian.org>" not changed

gpg: key 46925553: "Debian Archive Automatic Signing Key (7.0/wheezy) <ftpmaster@debian.org>" not changed

gpg: key 518E17E1: "Jessie Stable Release Key <debian-release@lists.debian.org>" not changed

gpg: key 2B90D010: "Debian Archive Automatic Signing Key (8/jessie) <ftpmaster@debian.org>" not changed

gpg: key C857C906: "Debian Security Archive Automatic Signing Key (8/jessie) <ftpmaster@debian.org>" not changed

gpg: Total number processed: 7

gpg:              unchanged: 7

测试再次升级：

root@mfus1006:~# apt-get update

Hit http://ftp.debian.org wheezy Release.gpg

Hit http://security.debian.org wheezy/updates Release.gpg

Hit http://ftp.debian.org wheezy Release

Hit http://security.debian.org wheezy/updates Release

Hit http://security.debian.org wheezy/updates/main i386 Packages

Hit http://ftp.debian.org wheezy/main i386 Packages

Hit http://security.debian.org wheezy/updates/contrib i386 Packages

Hit http://security.debian.org wheezy/updates/non-free i386 Packages

Hit http://ftp.debian.org wheezy/contrib i386 Packages

Hit http://security.debian.org wheezy/updates/contrib Translation-en

Hit http://security.debian.org wheezy/updates/main Translation-en

Hit http://ftp.debian.org wheezy/non-free i386 Packages

Hit http://security.debian.org wheezy/updates/non-free Translation-en

Hit http://ftp.debian.org wheezy/contrib Translation-en

Hit http://ftp.debian.org wheezy/main Translation-en

Hit http://ftp.debian.org wheezy/non-free Translation-en

Reading package lists... Done