我正在尝试将 Ubuntu 10 升级到 12，并将 archive.ubuntu.com 修改为 old-releases.ubuntu.com。但解析 security.ubuntu.com 仍然失败。旧版安全链接的正确 URL 应该是什么？
这是来源列表：
#
# deb cdrom:[Ubuntu-Server 8.04.3 _Hardy Heron_ - Release amd64 (20090709)]/ hardy main restricted
# deb cdrom:[Ubuntu-Server 8.04.3 _Hardy Heron_ - Release amd64 (20090709)]/ hardy main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://old-releases.ubuntu.com/ubuntu lucid main restricted
deb-src http://old-releases.ubuntu.com/ubuntu lucid main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://old-releases.ubuntu.com/ubuntu …upgrade ×1