Обновление apt-get сразу после загрузки приводит ко многим Ign и Hit, что приводит к ошибкам "без установки"

У меня странная проблема с фабричным сценарием, который я использую для загрузки сервера на EC2.

Я запускаю стандартную Ubuntu 12.04 AMI (ami-3d4ff254), жду, пока он запустится, затем продолжаю:

with settings(host_string="ubuntu@%s" % i.dns_name, 
              connection_attempts=30):
    sudo('apt-get -qy update')
    sudo('apt-get -qy install --no-install-recommends mdadm') # don't install postfix
    #etc...

apt-get update кажется, работает нормально и не дает ошибок, однако (2/3 времени или около того) установка mdadm выдает ошибку "нет кандидата на установку".

Когда я SSH в сервер и запускаю apt-get install mdadm Я получаю ту же ошибку. Бег apt-get update вручную, то пакет устанавливается нормально.

Любые идеи о том, что может происходить, или идеи для отладки?

РЕДАКТИРОВАТЬ: получается, добавив sleep(10) после того, как сервер SSH подходит и перед попыткой apt-get update это работает отлично. Похоже, что это проблема с настройкой apt для этого AMI в сочетании с, возможно, некоторой странностью на стороне Amazon или проблемами DNS.

Вот мои записи в /etc/apt/sources.list:

deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise main
deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise main
deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise-updates main
deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise-updates main
deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise universe
deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise universe
deb http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise-updates universe
deb-src http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise-updates universe
deb http://security.ubuntu.com/ubuntu precise-security main
deb-src http://security.ubuntu.com/ubuntu precise-security main
deb http://security.ubuntu.com/ubuntu precise-security universe
deb-src http://security.ubuntu.com/ubuntu precise-security universe

Вот вывод из apt-get update что испортил мой mdadm установить:

Ign http://security.ubuntu.com precise-security InRelease
Get:1 http://security.ubuntu.com precise-security Release.gpg [198 B]
Ign http://archive.ubuntu.com precise InRelease
Get:2 http://security.ubuntu.com precise-security Release [49.6 kB]
Ign http://archive.ubuntu.com precise-updates InRelease
Hit http://archive.ubuntu.com precise Release.gpg
Get:3 http://archive.ubuntu.com precise-updates Release.gpg [198 B]
Hit http://archive.ubuntu.com precise Release
Get:4 http://security.ubuntu.com precise-security/main amd64 Packages [177 kB]
Get:5 http://archive.ubuntu.com precise-updates Release [49.6 kB]
Hit http://archive.ubuntu.com precise/main amd64 Packages
Hit http://archive.ubuntu.com precise/restricted amd64 Packages
Hit http://archive.ubuntu.com precise/universe amd64 Packages
Hit http://archive.ubuntu.com precise/multiverse amd64 Packages
Hit http://archive.ubuntu.com precise/main i386 Packages
Hit http://archive.ubuntu.com precise/restricted i386 Packages
Hit http://archive.ubuntu.com precise/universe i386 Packages
Hit http://archive.ubuntu.com precise/multiverse i386 Packages
Get:6 http://security.ubuntu.com precise-security/restricted amd64 Packages [3,969 B]
Hit http://archive.ubuntu.com precise/main TranslationIndex
Get:7 http://security.ubuntu.com precise-security/universe amd64 Packages [48.6 kB]
Hit http://archive.ubuntu.com precise/multiverse TranslationIndex
Get:8 http://security.ubuntu.com precise-security/multiverse amd64 Packages [2,188 B]
Get:9 http://security.ubuntu.com precise-security/main i386 Packages [183 kB]
Hit http://archive.ubuntu.com precise/restricted TranslationIndex
Get:10 http://archive.ubuntu.com precise/universe TranslationIndex [2,922 B]
Get:11 http://archive.ubuntu.com precise-updates/main amd64 Packages [405 kB]
Get:12 http://security.ubuntu.com precise-security/restricted i386 Packages [3,968 B]
Get:13 http://security.ubuntu.com precise-security/universe i386 Packages [48.7 kB]
Get:14 http://security.ubuntu.com precise-security/multiverse i386 Packages [2,357 B]
Get:15 http://security.ubuntu.com precise-security/main TranslationIndex [73 B]
Get:16 http://security.ubuntu.com precise-security/multiverse TranslationIndex [71 B]
Get:17 http://security.ubuntu.com precise-security/restricted TranslationIndex [71 B]
Get:18 http://security.ubuntu.com precise-security/universe TranslationIndex [73 B]
Get:19 http://archive.ubuntu.com precise-updates/restricted amd64 Packages [8,215 B]
Get:20 http://archive.ubuntu.com precise-updates/universe amd64 Packages [149 kB]
Get:21 http://security.ubuntu.com precise-security/main Translation-en [86.5 kB]
Get:22 http://archive.ubuntu.com precise-updates/multiverse amd64 Packages [8,948 B]
Hit http://security.ubuntu.com precise-security/multiverse Translation-en
Get:23 http://archive.ubuntu.com precise-updates/main i386 Packages [410 kB]
Hit http://security.ubuntu.com precise-security/restricted Translation-en
Get:24 http://security.ubuntu.com precise-security/universe Translation-en [30.3 kB]
Get:25 http://archive.ubuntu.com precise-updates/restricted i386 Packages [8,218 B]
Get:26 http://archive.ubuntu.com precise-updates/universe i386 Packages [149 kB]
Get:27 http://archive.ubuntu.com precise-updates/multiverse i386 Packages [9,930 B]
Get:28 http://archive.ubuntu.com precise-updates/main TranslationIndex [3,564 B]
Get:29 http://archive.ubuntu.com precise-updates/multiverse TranslationIndex [2,605 B]
Get:30 http://archive.ubuntu.com precise-updates/restricted TranslationIndex [2,461 B]
Get:31 http://archive.ubuntu.com precise-updates/universe TranslationIndex [2,850 B]
Get:32 http://archive.ubuntu.com precise/main Translation-en [726 kB]
Get:33 http://archive.ubuntu.com precise/multiverse Translation-en [93.4 kB]
Get:34 http://archive.ubuntu.com precise/restricted Translation-en [2,395 B]
Get:35 http://archive.ubuntu.com precise/universe Translation-en [3,341 kB]
Get:36 http://archive.ubuntu.com precise-updates/main Translation-en [202 kB]
Get:37 http://archive.ubuntu.com precise-updates/multiverse Translation-en [5,606 B]
Get:38 http://archive.ubuntu.com precise-updates/restricted Translation-en [2,048 B]
Get:39 http://archive.ubuntu.com precise-updates/universe Translation-en [87.4 kB]
Ign http://archive.ubuntu.com precise/main Translation-en_US
Ign http://archive.ubuntu.com precise/multiverse Translation-en_US
Ign http://archive.ubuntu.com precise/restricted Translation-en_US
Fetched 6,308 kB in 8s (786 kB/s)
Reading package lists...

И вот вывод для того, который работает (т.е. после ожидания нескольких секунд, прежде чем делать apt-get update):

Ign http://us-east-1.ec2.archive.ubuntu.com precise InRelease
Ign http://us-east-1.ec2.archive.ubuntu.com precise-updates InRelease
Get:1 http://us-east-1.ec2.archive.ubuntu.com precise Release.gpg [198 B]
Get:2 http://us-east-1.ec2.archive.ubuntu.com precise-updates Release.gpg [198 B]
Get:3 http://us-east-1.ec2.archive.ubuntu.com precise Release [49.6 kB]
Ign http://security.ubuntu.com precise-security InRelease
Get:4 http://us-east-1.ec2.archive.ubuntu.com precise-updates Release [49.6 kB]
Get:5 http://security.ubuntu.com precise-security Release.gpg [198 B]
Get:6 http://us-east-1.ec2.archive.ubuntu.com precise/main Sources [934 kB]
Get:7 http://security.ubuntu.com precise-security Release [49.6 kB]
Get:8 http://us-east-1.ec2.archive.ubuntu.com precise/universe Sources [5,019 kB]
Get:9 http://us-east-1.ec2.archive.ubuntu.com precise/main amd64 Packages [1,273 kB]
Get:10 http://security.ubuntu.com precise-security/main Sources [50.1 kB]
Get:11 http://us-east-1.ec2.archive.ubuntu.com precise/universe amd64 Packages [4,786 kB]
Get:12 http://security.ubuntu.com precise-security/universe Sources [14.5 kB]
Get:13 http://security.ubuntu.com precise-security/main amd64 Packages [177 kB]
Get:14 http://us-east-1.ec2.archive.ubuntu.com precise/main i386 Packages [1,274 kB]
Get:15 http://security.ubuntu.com precise-security/universe amd64 Packages [48.6 kB]
Get:16 http://us-east-1.ec2.archive.ubuntu.com precise/universe i386 Packages [4,796 kB]
Get:17 http://security.ubuntu.com precise-security/main i386 Packages [183 kB]
Get:18 http://us-east-1.ec2.archive.ubuntu.com precise/main TranslationIndex [3,706 B]
Get:19 http://us-east-1.ec2.archive.ubuntu.com precise/universe TranslationIndex [2,922 B]
Get:20 http://us-east-1.ec2.archive.ubuntu.com precise-updates/main Sources [178 kB]
Get:21 http://security.ubuntu.com precise-security/universe i386 Packages [48.7 kB]
Get:22 http://us-east-1.ec2.archive.ubuntu.com precise-updates/universe Sources [60.2 kB]
Get:23 http://security.ubuntu.com precise-security/main TranslationIndex [73 B]
Get:24 http://us-east-1.ec2.archive.ubuntu.com precise-updates/main amd64 Packages [405 kB]
Get:25 http://us-east-1.ec2.archive.ubuntu.com precise-updates/universe amd64 Packages [149 kB]
Get:26 http://security.ubuntu.com precise-security/universe TranslationIndex [73 B]
Get:27 http://security.ubuntu.com precise-security/main Translation-en [86.5 kB]
Get:28 http://security.ubuntu.com precise-security/universe Translation-en [30.3 kB]
Get:29 http://us-east-1.ec2.archive.ubuntu.com precise-updates/main i386 Packages [410 kB]
Get:30 http://us-east-1.ec2.archive.ubuntu.com precise-updates/universe i386 Packages [149 kB]
Get:31 http://us-east-1.ec2.archive.ubuntu.com precise-updates/main TranslationIndex [3,564 B]
Get:32 http://us-east-1.ec2.archive.ubuntu.com precise-updates/universe TranslationIndex [2,850 B]
Get:33 http://us-east-1.ec2.archive.ubuntu.com precise/main Translation-en [726 kB]
Get:34 http://us-east-1.ec2.archive.ubuntu.com precise/universe Translation-en [3,341 kB]
Get:35 http://us-east-1.ec2.archive.ubuntu.com precise-updates/main Translation-en [202 kB]
Get:36 http://us-east-1.ec2.archive.ubuntu.com precise-updates/universe Translation-en [87.4 kB]
Fetched 24.6 MB in 12s (1,976 kB/s)
Reading package lists...

Я не знаю, почему в первом полно Hitс и Igns.