Eu encontrei a mesma situação.
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages Hash Sum mismatch
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-updates/main/binary-amd64/Packages Hash Sum mismatch
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-updates/universe/binary-amd64/Packages Hash Sum mismatch
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-updates/universe/binary-i386/Packages Hash Sum mismatch
E: Some index files failed to download. They have been ignored, or old ones used instead.
Primeiro, eu editei o apt.conf
Debug::Acquire::http true;
Debug::pkgAcquire::Auth true;
Debug::Hashs true;
então, pesquisou http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages
na saída do comando apt-get update
, e achou isso:
Get:1 http://security.ubuntu.com vivid-security/main amd64 Packages [115 kB]
100% [1 Packages 115 kB/115 kB 100%] [Waiting for headers] [Connecting to security.ubuntu.com (91.189.91.15)]201 URI Done: http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages.bz2
RecivedHash: SHA256:0460b45fe9ace5ddb1e2080df5f75a6ee5d950fa451733991ec1b2b303bd16f6
ExpectedHash: SHA256:9daf23b84605ff833d1d280f837bd87fcbc3c7e0ca9403590985f970ee561f61
100% [1 Packages bzip2 0 B] [Waiting for headers] [Connecting to security.ubuntu.com (91.189.91.15)]201 URI Done: bzip2:/var/lib/apt/lists/partial/security.ubuntu.com_ubuntu_dists_vivid-security_main_binary-amd64_Packages.bz2
RecivedHash: SHA256:f10f6ef0486182bc9369e7912ddb9cf536c3049813ffd169b84f34dcda540ace
ExpectedHash: SHA256:9daf23b84605ff833d1d280f837bd87fcbc3c7e0ca9403590985f970ee561f61
http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages: Computed Hash: SHA256:f10f6ef0486182bc9369e7912ddb9cf536c3049813ffd169b84f34dcda540ace Expected Hash: SHA256:9daf23b84605ff833d1d280f837bd87fcbc3c7e0ca9403590985f970ee561f61
100% [Waiting for headers] [Connecting to security.ubuntu.com (91.189.91.15)]GET /ubuntu/dists/vivid-security/multiverse/binary-amd64/Packages.bz2 HTTP/1.1
Host: security.ubuntu.com
Cache-Control: max-age=0
Range: bytes=5195-
If-Range: Mon, 28 Sep 2015 14:33:00 GMT
User-Agent: Debian APT-HTTP/1.3 (1.0.9.7ubuntu4)
Obviamente, o arquivo de pacotes baixado não estava certo. Então eu baixei http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages.bz2
e http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages.gz
, descompactei-os e verifiquei a soma do hash manualmente:
$ wget http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages.bz2
$ wget http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages.gz
$ sha256sum Packages*
0460b45fe9ace5ddb1e2080df5f75a6ee5d950fa451733991ec1b2b303bd16f6 Packages.bz2
f10f6ef0486182bc9369e7912ddb9cf536c3049813ffd169b84f34dcda540ace Packages.from.bz2
9daf23b84605ff833d1d280f837bd87fcbc3c7e0ca9403590985f970ee561f61 Packages.from.gz
b6b70b8f7838d742104904d461677652cf5120f9b8302841cb017c0c5c9dea40 Packages.gz
Descobrimos que http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages.bz2
contém um arquivo Packages errado, mas o http://security.ubuntu.com/ubuntu/dists/vivid-security/main/binary-amd64/Packages.gz
contém o arquivo correto que não é baixado por padrão.
Então edite o apt.conf:
Acquire::CompressionTypes::Order:: "gz";
Funcionou para mim. Boa sorte!