title: composer.phar very slow and not completing install or update
body: <p>I must use composer on my own nas server for a php web project.
  Composer is available there on my nas, i downloaded the newest version, but if I call install or update, it need a long time and then composer does nothing anymore (no furthed progress, it stucks on "writing to cache" or "reading from cache").</p>
  
  <p>Eatings for a few hours:</p>
  
  <pre><code>CPU: 0 - 19%
  HDD: 70%!
  RAM: 70 - 80%
  </code></pre>
  
  <p>... but no progress. Composer looks like he paused and do nothing. You will see the composer output logfile soon.</p>
  
  <p>I would like to show you my composer.json:</p>
  
  <pre><code>    {
          "name": "symfony/framework-standard-edition",
          "license": "MIT",
          "type": "project",
          "description": "The \"Symfony Standard Edition\" distribution",
          "autoload": {
              "psr-0": { "": "src/" }
          },
          "require": {
              "php": "&gt;=5.3.3",
              "symfony/symfony": "~2.4",
              "doctrine/orm": "~2.2,&gt;=2.2.3",
              "doctrine/doctrine-bundle": "~1.2",
              "twig/extensions": "~1.0",
              "symfony/assetic-bundle": "~2.3",
              "symfony/swiftmailer-bundle": "~2.3",
              "symfony/monolog-bundle": "~2.4",
              "sensio/distribution-bundle": "~2.3",
              "sensio/framework-extra-bundle": "~3.0",
              "sensio/generator-bundle": "~2.3",
              "incenteev/composer-parameter-handler": "~2.0",
              "doctrine/doctrine-fixtures-bundle": "dev-master",
              "doctrine/data-fixtures" : "dev-master",
              "raveren/kint": "@dev",
              "cg/kint-bundle": "dev-master"
          },
          "scripts": {
              "post-install-cmd": [
                  "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
                  "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
                  "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
                  "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
                  "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile"
              ],
              "post-update-cmd": [
                  "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
                  "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
                  "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
                  "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
                  "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile"
              ]
          },
          "config": {
              "bin-dir": "bin"
          },
          "minimum-stability": "dev",
          "extra": {
              "symfony-app-dir": "app",
              "symfony-web-dir": "web",
              "incenteev-parameters": {
                  "file": "app/config/parameters.yml"
              },
              "branch-alias": {
                  "dev-master": "2.4-dev"
              }
          }
      }
  </code></pre>
  
  <p>Here's my call to start composer:</p>
  
  <pre><code>php composer.phar update --prefer-dist -vvv --profile &gt;./composer.log.txt
  </code></pre>
  
  <p>He run a long time and after some "hours" (!!) i killed it with CTRL + C. 
  It is no problem, if composer would need a long time, maybe some hours, but he should finish his work at least.
  I have to tell something about the nas. It is not powerful. 1.2 GHz, 128 MB RAM. So this could be a big problem for running composer?</p>
  
  <p>xdebug is deactivated.</p>
  
  <p>Here's the composer log output, composer.log.txt:</p>
  
  <pre><code>[0.9MB/0.11s] Reading ./composer.json
  [0.9MB/0.20s] Loading config file ./composer.json
  [0.9MB/0.30s] Executing command (CWD): git describe --exact-match --tags
  [1.0MB/0.68s] Executing command (CWD): git branch --no-color --no-abbrev -v
  [1.6MB/1.41s] Loading composer repositories with package information
  [1.7MB/1.50s] Downloading https://packagist.org/packages.json
  [1.7MB/1.71s] Writing /root/.composer/cache/repo/https---packagist.org/packages.json into cache
  [1.7MB/1.78s] Updating dependencies (including require-dev)
  [1.7MB/1.83s] Reading /root/.composer/cache/repo/https---packagist.org/p-provider-active.json from cache
  [4.1MB/2.14s] Reading /root/.composer/cache/repo/https---packagist.org/p-provider-archived.json from cache
  [9.2MB/2.78s] Downloading https://packagist.org/p/provider-latest$27f0883b66e23851d98d77f3f2d38b260f97886ecaef58ba5270dc855617f31d.json
  [13.9MB/3.66s] Writing /root/.composer/cache/repo/https---packagist.org/p-provider-latest.json into cache
  [12.6MB/3.95s] Downloading https://packagist.org/p/provider-stale$8f6a69f2604637ea5a49e850799189ce535eef932daa4cd3a975876dfde82ece.json
  [16.6MB/4.78s] Writing /root/.composer/cache/repo/https---packagist.org/p-provider-stale.json into cache
  [15.1MB/5.18s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$data-fixtures.json from cache
  [15.1MB/5.24s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$doctrine-fixtures-bundle.json from cache
  [15.2MB/5.38s] Reading /root/.composer/cache/repo/https---packagist.org/provider-jdorn$sql-formatter.json from cache
  [15.2MB/5.41s] Reading /root/.composer/cache/repo/https---packagist.org/provider-psr$log.json from cache
  [15.2MB/5.43s] Reading /root/.composer/cache/repo/https---packagist.org/provider-twig$twig.json from cache
  [15.4MB/5.55s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$lexer.json from cache
  [15.5MB/5.56s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$annotations.json from cache
  [15.5MB/5.59s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$collections.json from cache
  [15.5MB/5.61s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$cache.json from cache
  [15.6MB/5.64s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$inflector.json from cache
  [15.6MB/5.66s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$common.json from cache
  [15.9MB/5.86s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$dbal.json from cache
  [16.4MB/6.42s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$doctrine-bridge.json from cache
  [23.3MB/13.20s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$framework-bundle.json from cache
  [24.9MB/14.40s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$doctrine-bundle.json from cache
  [25.1MB/14.65s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$config.json from cache
  [25.5MB/15.39s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$http-kernel.json from cache
  [27.9MB/16.32s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$filesystem.json from cache
  [28.3MB/16.68s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$routing.json from cache
  [29.0MB/17.45s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$stopwatch.json from cache
  [29.3MB/17.73s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$translation.json from cache
  [29.8MB/18.24s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$dependency-injection.json from cache
  [30.4MB/18.83s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$event-dispatcher.json from cache
  [31.0MB/19.70s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$templating.json from cache
  [31.5MB/20.71s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$http-foundation.json from cache
  [31.9MB/21.23s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$security-core.json from cache
  [32.6MB/21.92s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$security-csrf.json from cache
  [33.5MB/23.54s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$debug.json from cache
  [33.2MB/26.25s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$doctrine-cache-bundle.json from cache
  [33.3MB/26.36s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$security.json from cache
  [34.2MB/28.09s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$process.json from cache
  [34.6MB/28.49s] Reading /root/.composer/cache/repo/https---packagist.org/provider-kriswallsmith$assetic.json from cache
  [34.9MB/28.84s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$options-resolver.json from cache
  [35.2MB/29.16s] Reading /root/.composer/cache/repo/https---packagist.org/provider-knplabs$gaufrette.json from cache
  [35.4MB/29.46s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$finder.json from cache
  [35.8MB/30.25s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$assetic-bundle.json from cache
  [36.5MB/36.41s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$console.json from cache
  [37.0MB/36.86s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$orm.json from cache
  [37.7MB/37.56s] Reading /root/.composer/cache/repo/https---packagist.org/provider-doctrine$instantiator.json from cache
  [37.7MB/37.63s] Reading /root/.composer/cache/repo/https---packagist.org/provider-twig$extensions.json from cache
  [37.8MB/37.67s] Reading /root/.composer/cache/repo/https---packagist.org/provider-swiftmailer$swiftmailer.json from cache
  [37.9MB/37.76s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$swiftmailer-bridge.json from cache
  [38.4MB/38.22s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$swiftmailer-bundle.json from cache
  [38.8MB/38.72s] Reading /root/.composer/cache/repo/https---packagist.org/provider-sensio$distribution-bundle.json from cache
  [39.1MB/39.19s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$class-loader.json from cache
  [39.6MB/39.66s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$form.json from cache
  [40.5MB/40.43s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$validator.json from cache
  [41.4MB/41.43s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$yaml.json from cache
  [42.9MB/42.52s] Reading /root/.composer/cache/repo/https---packagist.org/provider-sensiolabs$security-checker.json from cache
  [42.9MB/42.69s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$property-access.json from cache
  [43.2MB/42.96s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$locale.json from cache
  [43.7MB/43.77s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$intl.json from cache
  [44.6MB/44.70s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$icu.json from cache
  [44.2MB/45.34s] Reading /root/.composer/cache/repo/https---packagist.org/provider-sensio$generator-bundle.json from cache
  [44.6MB/45.93s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$doctrine-bundle.json from cache
  [44.6MB/46.20s] Reading /root/.composer/cache/repo/https---packagist.org/provider-incenteev$composer-parameter-handler.json from cache
  [44.6MB/46.39s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$symfony.json from cache
  [44.7MB/46.55s] Reading /root/.composer/cache/repo/https---packagist.org/provider-monolog$monolog.json from cache
  [44.9MB/47.06s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$monolog-bridge.json from cache
  [45.5MB/47.61s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$monolog-bundle.json from cache
  [45.9MB/48.94s] Reading /root/.composer/cache/repo/https---packagist.org/provider-sensio$framework-extra-bundle.json from cache
  [46.2MB/49.30s] Reading /root/.composer/cache/repo/https---packagist.org/provider-raveren$kint.json from cache
  [46.3MB/49.32s] Reading /root/.composer/cache/repo/https---packagist.org/provider-cg$kint-bundle.json from cache
  [46.3MB/49.34s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$framework-standard-edition.json from cache
  [49.3MB/50.39s] Reading /root/.composer/cache/repo/https---packagist.org/provider-jms$security-extra-bundle.json from cache
  [49.4MB/50.49s] Reading /root/.composer/cache/repo/https---packagist.org/provider-jms$di-extra-bundle.json from cache
  [49.6MB/50.67s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$security-bundle.json from cache
  [50.3MB/51.34s] Reading /root/.composer/cache/repo/https---packagist.org/provider-jms$metadata.json from cache
  [50.4MB/51.39s] Reading /root/.composer/cache/repo/https---packagist.org/provider-jms$aop-bundle.json from cache
  [50.5MB/52.92s] Reading /root/.composer/cache/repo/https---packagist.org/provider-jms$cg.json from cache
  [50.5MB/53.17s] Reading /root/.composer/cache/repo/https---packagist.org/provider-jms$parser-lib.json from cache
  [50.5MB/53.25s] Reading /root/.composer/cache/repo/https---packagist.org/provider-phpoption$phpoption.json from cache
  [56.5MB/58.98s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$browser-kit.json from cache
  [57.2MB/62.36s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$css-selector.json from cache
  [57.6MB/63.24s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$dom-crawler.json from cache
  [58.1MB/64.05s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$propel1-bridge.json from cache
  [58.6MB/64.73s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$serializer.json from cache
  [59.0MB/67.62s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$twig-bridge.json from cache
  [60.1MB/68.66s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$twig-bundle.json from cache
  [60.7MB/69.85s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$web-profiler-bundle.json from cache
  [61.6MB/73.41s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$proxy-manager-bridge.json from cache
  [61.9MB/74.49s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$expression-language.json from cache
  [62.0MB/75.01s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$security-acl.json from cache
  [62.3MB/87.77s] Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$security-http.json from cache
  [86.6MB/299.81s] Downloading http://packagist.org/p/symfony/doctrine-abstract-bundle$557a1f9a31777860331e98ff2877ea8d8caf0d14519abf3d20cba65cf3ad4fc0.json
  [87.1MB/300.38s] Writing /root/.composer/cache/repo/https---packagist.org/provider-symfony$doctrine-abstract-bundle.json into cache
  </code></pre>
  
  <p>No further progress at "Writing /root/.composer/cache/repo/https---packagist.org/provider-symfony$doctrine-abstract-bundle.json into cache" for 7 hours. But the HDD was working a lot.</p>
  
  <p>I tried again for a very long time and then composer stucked on "Reading /root/.composer/cache/repo/https---packagist.org/provider-symfony$doctrine-abstract-bundle.json from cache".</p>
  
  <p>Do you know what to do to fix this?
  I would be glad about every advice. Thank you.</p>