title: gitlab backup: make gitlab-rake produce tar.gz files not tar
body: <p>Backup files I get with <code>gitlab-rake</code> are tar files how can I get <code>tar.gz</code> ?</p>
  
  <p>Here the files::</p>
  
  <pre><code>root@gitlab:~# ll /mnt/backup-git/ -h
  total 1.9G
  -rw------- 1 git  git   57M Nov 29 15:57 1480431448_gitlab_backup.tar
  -rw------- 1 git  git   57M Nov 29 15:57 1480431473_gitlab_backup.tar
  -rw------- 1 git  git  452M Nov 30 02:00 1480467623_gitlab_backup.tar
  </code></pre>
  
  <p>Here my configuration values for the backup::</p>
  
  <pre><code>$ grep -i backup /etc/gitlab/gitlab.rb | grep -v '^#'
  gitlab_rails['backup_path'] = "/mnt/backup-git/"
  gitlab_rails['backup_keep_time'] = 604800
  </code></pre>
  
  <p>To create them, following the documentation <a href="https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/raketasks/backup_restore.md" rel="nofollow noreferrer">here</a>, (omnibus installation):</p>
  
  <pre><code>root@gitlab:~# crontab -l | grep -v '^#'
  0 2 * * * /opt/gitlab/bin/gitlab-rake gitlab:backup:create CRON=1
  </code></pre>