failure to upgrade to 14.10 with defunct mirror

[Kathik]

Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Building data structures... Done

Invalid package information

After updating your package information, the essential package
'ubuntu-minimal' could not be located. This may be because you have
no official mirrors listed in your software sources, or because of
excessive load on the mirror you are using. See /etc/apt/sources.list
for the current list of configured software sources.
In the case of an overloaded mirror, you may want to try the upgrade
again later.

Restoring original system state

Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done
Building data structures... Done
user@token:~/Downloads$ Using PPAPI flash.
Created new window in existing browser session.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubuntu-release-upgrader-core 1:0.220.7 [origin: unknown]
ProcVersionSignature: Ubuntu 3.19.0-30.33~14.04.1-generic 3.19.8-ckt6
Uname: Linux 3.19.0-30-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.10
Architecture: amd64
CrashDB: ubuntu
Date: Thu Apr 20 12:18:25 2017
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-trusty-amd64-osp1-20150720-0
InstallationDate: Installed on 2017-03-16 (34 days ago)
InstallationMedia: Ubuntu 14.04 "Trusty" - Build amd64 LIVE Binary 20150720-04:06
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_IN:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_IN
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to trusty on 2017-04-20 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2017-04-20 12:16:41.478683
 Log time: 2017-04-20 12:17:02.151775
 Log time: 2017-04-20 12:18:24.846834
 Log time: 2017-04-20 12:18:25.738407
mtime.conffile..etc.update.manager.release.upgrades: 2017-04-19T18:03:15.570572

[Brian Murray (brian-murray)]

The mirror of Ubuntu you are using (http://archive.poldownload.com/ubuntu/) is not an official one and no longer seems to be accessible. Additionally, you are trying to upgrade to Ubuntu 14.10 which is no longer supported. Please edit the file '/etc/update-manager/release-upgrades' and set "Prompt=lts" so the upgrade path will be from Ubuntu 14.04 to Ubuntu 16.04.

[Launchpad Janitor (janitor)]

[Expired for ubuntu-release-upgrader (Ubuntu) because there has been no activity for 60 days.]