diff --git a/.gitignore b/.gitignore
index 26af5221f..7fd06517e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,7 +17,6 @@ src/borg/platform/posix.c
 src/borg/_version.py
 *.egg-info
 *.pyc
-*.pyo
 *.so
 .idea/
 .cache/
diff --git a/.travis.yml b/.travis.yml
index e12266b9d..572cc9a08 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,14 +6,9 @@ cache:
     directories:
         - $HOME/.cache/pip
 
-# note: use py 3.5.2, it has lzma support. 3.5(.0) on travis.org/trusty does not.
 matrix:
     include:
-        - python: 3.4
-          os: linux
-          dist: trusty
-          env: TOXENV=py34
-        - python: 3.5.2
+        - python: 3.5
           os: linux
           dist: trusty
           env: TOXENV=py35
@@ -21,7 +16,7 @@ matrix:
           os: linux
           dist: trusty
           env: TOXENV=py36
-        - python: 3.4
+        - python: 3.5
           os: linux
           dist: trusty
           env: TOXENV=flake8
@@ -29,10 +24,6 @@ matrix:
           os: linux
           dist: trusty
           env: TOXENV=py36
-        - language: generic
-          os: osx
-          osx_image: xcode6.4
-          env: TOXENV=py34
         - language: generic
           os: osx
           osx_image: xcode6.4
diff --git a/.travis/install.sh b/.travis/install.sh
index 708b8c81b..4ffc99359 100755
--- a/.travis/install.sh
+++ b/.travis/install.sh
@@ -21,10 +21,6 @@ if [[ "$(uname -s)" == 'Darwin' ]]; then
     brew install Caskroom/cask/osxfuse
 
     case "${TOXENV}" in
-        py34)
-            pyenv install 3.4.5
-            pyenv global 3.4.5
-            ;;
         py35)
             pyenv install 3.5.2
             pyenv global 3.5.2
diff --git a/MANIFEST.in b/MANIFEST.in
index 2ec72dc24..bdabc64d0 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -5,4 +5,4 @@ prune .github
 graft src
 graft docs
 prune docs/_build
-global-exclude *.py[co] *.orig *.so *.dll
+global-exclude *.pyc *.orig *.so *.dll
diff --git a/Vagrantfile b/Vagrantfile
index 87897c023..669c0975a 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -7,13 +7,6 @@ $cpus = Integer(ENV.fetch('VMCPUS', '4'))  # create VMs with that many cpus
 $xdistn = Integer(ENV.fetch('XDISTN', '4'))  # dispatch tests to that many pytest workers
 $wmem = $xdistn * 256  # give the VM additional memory for workers [MB]
 
-def packages_prepare_wheezy
-  return <<-EOF
-      # debian 7 wheezy does not have lz4, but it is available from wheezy-backports:
-      echo "deb http://http.debian.net/debian wheezy-backports main" > /etc/apt/sources.list.d/wheezy-backports.list
-  EOF
-end
-
 def packages_debianoid
   return <<-EOF
     if id "vagrant" >/dev/null 2>&1; then
@@ -35,199 +28,16 @@ def packages_debianoid
     apt-get install -y python3-dev python3-setuptools
     # for building python:
     apt-get install -y zlib1g-dev libbz2-dev libncurses5-dev libreadline-dev liblzma-dev libsqlite3-dev
-    # this way it works on older dists (like ubuntu 12.04) also:
-    # for python 3.2 on ubuntu 12.04 we need pip<8 and virtualenv<14 as
-    # newer versions are not compatible with py 3.2 any more.
-    easy_install3 'pip<8.0'
-    pip3 install 'virtualenv<14.0'
+    easy_install3 'pip'
+    pip3 install 'virtualenv'
     touch $home_dir/.bash_profile ; chown $username $home_dir/.bash_profile
   EOF
 end
 
-def packages_redhatted
-  return <<-EOF
-    yum install -y epel-release
-    yum update -y
-    # for building borgbackup and dependencies:
-    yum install -y openssl-devel openssl libacl-devel libacl lz4-devel fuse-devel fuse pkgconfig
-    usermod -a -G fuse vagrant
-    chgrp fuse /dev/fuse
-    chmod 666 /dev/fuse
-    yum install -y fakeroot gcc git patch
-    # needed to compile msgpack-python (otherwise it will use slow fallback code):
-    yum install -y gcc-c++
-    # for building python:
-    yum install -y zlib-devel bzip2-devel ncurses-devel readline-devel xz xz-devel sqlite-devel
-    #yum install -y python-pip
-    #pip install virtualenv
-    touch ~vagrant/.bash_profile ; chown vagrant ~vagrant/.bash_profile
-  EOF
-end
-
-def packages_darwin
-  return <<-EOF
-    # install all the (security and other) updates
-    sudo softwareupdate --ignore iTunesX
-    sudo softwareupdate --ignore iTunes
-    sudo softwareupdate --install --all
-    # get osxfuse 3.x release code from github:
-    curl -s -L https://github.com/osxfuse/osxfuse/releases/download/osxfuse-3.6.3/osxfuse-3.6.3.dmg >osxfuse.dmg
-    MOUNTDIR=$(echo `hdiutil mount osxfuse.dmg | tail -1 | awk '{$1="" ; print $0}'` | xargs -0 echo) \
-    && sudo installer -pkg "${MOUNTDIR}/Extras/FUSE for macOS 3.6.3.pkg" -target /
-    sudo chown -R vagrant /usr/local  # brew must be able to create stuff here
-    ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
-    brew update
-    brew install openssl
-    brew install lz4
-    brew install xz  # required for python lzma module
-    brew install fakeroot
-    brew install git
-    brew install pkg-config
-    touch ~vagrant/.bash_profile ; chown vagrant ~vagrant/.bash_profile
-  EOF
-end
-
-def packages_freebsd
-  return <<-EOF
-    # VM has no hostname set
-    hostname freebsd
-    # install all the (security and other) updates, base system
-    freebsd-update --not-running-from-cron fetch install
-    # for building borgbackup and dependencies:
-    pkg install -y openssl liblz4 fusefs-libs pkgconf
-    pkg install -y git bash
-    # for building python:
-    pkg install -y sqlite3
-    # make bash default / work:
-    chsh -s bash vagrant
-    mount -t fdescfs fdesc /dev/fd
-    echo 'fdesc	/dev/fd		fdescfs		rw	0	0' >> /etc/fstab
-    # make FUSE work
-    echo 'fuse_load="YES"' >> /boot/loader.conf
-    echo 'vfs.usermount=1' >> /etc/sysctl.conf
-    kldload fuse
-    sysctl vfs.usermount=1
-    pw groupmod operator -M vagrant
-    # /dev/fuse has group operator
-    chmod 666 /dev/fuse
-    touch ~vagrant/.bash_profile ; chown vagrant ~vagrant/.bash_profile
-    # install all the (security and other) updates, packages
-    pkg update
-    yes | pkg upgrade
-  EOF
-end
-
-def packages_openbsd
-  return <<-EOF
-    echo 'installpath = http://ftp.hostserver.de/pub/OpenBSD/6.0/packages/amd64/' > /etc/pkg.conf
-    echo 'export PKG_PATH=http://ftp.hostserver.de/pub/OpenBSD/6.0/packages/amd64/' >> ~/.profile
-    . ~/.profile
-    pkg_add bash
-    chsh -s /usr/local/bin/bash vagrant
-    pkg_add openssl
-    pkg_add lz4
-    pkg_add git  # no fakeroot
-    pkg_add py3-setuptools
-    ln -sf /usr/local/bin/python3.4 /usr/local/bin/python3
-    ln -sf /usr/local/bin/python3.4 /usr/local/bin/python
-    easy_install-3.4 pip
-    pip3 install virtualenv
-    touch ~vagrant/.bash_profile ; chown vagrant ~vagrant/.bash_profile
-  EOF
-end
-
-def packages_netbsd
-  return <<-EOF
-    hostname netbsd  # the box we use has an invalid hostname
-    PKG_PATH="ftp://ftp.NetBSD.org/pub/pkgsrc/packages/NetBSD/amd64/6.1.5/All/"
-    export PKG_PATH
-    pkg_add mozilla-rootcerts lz4 git bash
-    chsh -s bash vagrant
-    mkdir -p /usr/local/opt/lz4/include
-    mkdir -p /usr/local/opt/lz4/lib
-    ln -s /usr/pkg/include/lz4*.h /usr/local/opt/lz4/include/
-    ln -s /usr/pkg/lib/liblz4* /usr/local/opt/lz4/lib/
-    touch /etc/openssl/openssl.cnf  # avoids a flood of "can't open ..."
-    mozilla-rootcerts install
-    pkg_add pkg-config  # avoids some "pkg-config missing" error msg, even without fuse pkg
-    # pkg_add fuse  # llfuse supports netbsd, but is still buggy.
-    # https://bitbucket.org/nikratio/python-llfuse/issues/70/perfuse_open-setsockopt-no-buffer-space
-    pkg_add python34 py34-setuptools
-    ln -s /usr/pkg/bin/python3.4 /usr/pkg/bin/python
-    ln -s /usr/pkg/bin/python3.4 /usr/pkg/bin/python3
-    easy_install-3.4 pip
-    pip install virtualenv
-    touch ~vagrant/.bash_profile ; chown vagrant ~vagrant/.bash_profile
-  EOF
-end
-
-def packages_openindiana
-  return <<-EOF
-    #pkg update  # XXX needs separate provisioning step + reboot
-    pkg install python-34 clang-3.4 lz4 git
-    python3 -m ensurepip
-    pip3 install -U setuptools pip wheel virtualenv
-    touch ~vagrant/.bash_profile ; chown vagrant ~vagrant/.bash_profile
-  EOF
-end
-
-# Install required cygwin packages and configure environment
-#
-# Microsoft/EdgeOnWindows10 image has MLS-OpenSSH installed by default,
-# which is based on cygwin x86_64 but should not be used together with cygwin.
-# In order to have have cygwin compatible bash 'ImagePath' is replaced with
-# cygrunsrv of newly installed cygwin
-#
-# supported cygwin versions:
-#   x86_64
-#   x86
-def packages_cygwin(version)
-  setup_exe = "setup-#{version}.exe"
-
-  return <<-EOF
-    mkdir -p /cygdrive/c/cygwin
-    powershell -Command '$client = new-object System.Net.WebClient; $client.DownloadFile("https://www.cygwin.com/#{setup_exe}","C:\\cygwin\\#{setup_exe}")'
-    echo '
-    REM --- Change to use different CygWin platform and final install path
-    set CYGSETUP=#{setup_exe}
-    REM --- Install build version of CygWin in a subfolder
-    set OURPATH=%cd%
-    set CYGBUILD="C:\\cygwin\\CygWin"
-    set CYGMIRROR=http://mirrors.kernel.org/sourceware/cygwin/
-    set BASEPKGS=openssh,rsync
-    set BUILDPKGS=python3,python3-setuptools,python-devel,binutils,gcc-g++,libopenssl,openssl-devel,git,make,liblz4-devel,liblz4_1,curl
-    %CYGSETUP% -q -B -o -n -R %CYGBUILD% -L -D -s %CYGMIRROR% -P %BASEPKGS%,%BUILDPKGS%
-    cd /d C:\\cygwin\\CygWin\\bin
-    regtool set /HKLM/SYSTEM/CurrentControlSet/Services/OpenSSHd/ImagePath "C:\\cygwin\\CygWin\\bin\\cygrunsrv.exe"
-    bash -c "ssh-host-config --no"
-    bash -c "chown sshd_server /cygdrive/c/cygwin/CygWin/var/empty"
-    ' > /cygdrive/c/cygwin/install.bat
-
-    echo "alias mkdir='mkdir -p'" > ~/.profile
-    echo "export CYGWIN_ROOT=/cygdrive/c/cygwin/CygWin" >> ~/.profile
-    echo 'export PATH=$CYGWIN_ROOT/bin:$PATH' >> ~/.profile
-
-    echo '' > ~/.bash_profile
-
-    cmd.exe /c 'setx /m PATH "C:\\cygwin\\CygWin\\bin;%PATH%"'
-    source ~/.profile
-    cd /cygdrive/c/cygwin && cmd.exe /c install.bat
-
-    echo 'db_home: windows' > $CYGWIN_ROOT/etc/nsswitch.conf
-  EOF
-end
-
-def install_cygwin_venv
-  return <<-EOF
-      python3 -m ensurepip -U --default-pip
-      pip install virtualenv
-  EOF
-end
-
 def install_pyenv(boxname)
   script = <<-EOF
     curl -s -L https://raw.githubusercontent.com/yyuu/pyenv-installer/master/bin/pyenv-installer | bash
-    echo 'export PATH="$HOME/.pyenv/bin:/vagrant/borg:$PATH"' >> ~/.bash_profile
+    echo 'export PATH="$HOME/.pyenv/bin:$PATH"' >> ~/.bash_profile
     echo 'eval "$(pyenv init -)"' >> ~/.bash_profile
     echo 'eval "$(pyenv virtualenv-init -)"' >> ~/.bash_profile
     echo 'export PYTHON_CONFIGURE_OPTS="--enable-shared"' >> ~/.bash_profile
@@ -246,7 +56,6 @@ end
 def install_pythons(boxname)
   return <<-EOF
     . ~/.bash_profile
-    pyenv install 3.4.0  # tests
     pyenv install 3.5.0  # tests
     pyenv install 3.6.0  # tests
     pyenv install 3.5.3  # binary build, use latest 3.5.x release
@@ -320,6 +129,7 @@ def build_binary_with_pyinstaller(boxname)
     . borg-env/bin/activate
     cd borg
     pyinstaller --clean --distpath=/vagrant/borg scripts/borg.exe.spec
+    echo 'export PATH="/vagrant/borg:$PATH"' >> ~/.bash_profile
   EOF
 end
 
@@ -330,8 +140,8 @@ def run_tests(boxname)
     . ../borg-env/bin/activate
     if which pyenv 2> /dev/null; then
       # for testing, use the earliest point releases of the supported python versions:
-      pyenv global 3.4.0 3.5.0 3.6.0
-      pyenv local 3.4.0 3.5.0 3.6.0
+      pyenv global 3.5.0 3.6.0
+      pyenv local 3.5.0 3.6.0
     fi
     # otherwise: just use the system python
     if which fakeroot 2> /dev/null; then
@@ -369,46 +179,6 @@ Vagrant.configure(2) do |config|
     v.cpus = $cpus
   end
 
-  # Linux
-  config.vm.define "centos7_64" do |b|
-    b.vm.box = "centos/7"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1024 + $wmem
-    end
-    b.vm.provision "install system packages", :type => :shell, :inline => packages_redhatted
-    b.vm.provision "install pyenv", :type => :shell, :privileged => false, :inline => install_pyenv("centos7_64")
-    b.vm.provision "install pythons", :type => :shell, :privileged => false, :inline => install_pythons("centos7_64")
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_pyenv_venv("centos7_64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(true)
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("centos7_64")
-  end
-
-  config.vm.define "centos6_32" do |b|
-    b.vm.box = "centos6-32"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 768 + $wmem
-    end
-    b.vm.provision "install system packages", :type => :shell, :inline => packages_redhatted
-    b.vm.provision "install pyenv", :type => :shell, :privileged => false, :inline => install_pyenv("centos6_32")
-    b.vm.provision "install pythons", :type => :shell, :privileged => false, :inline => install_pythons("centos6_32")
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_pyenv_venv("centos6_32")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(false)
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("centos6_32")
-  end
-
-  config.vm.define "centos6_64" do |b|
-    b.vm.box = "centos6-64"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1024 + $wmem
-    end
-    b.vm.provision "install system packages", :type => :shell, :inline => packages_redhatted
-    b.vm.provision "install pyenv", :type => :shell, :privileged => false, :inline => install_pyenv("centos6_64")
-    b.vm.provision "install pythons", :type => :shell, :privileged => false, :inline => install_pythons("centos6_64")
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_pyenv_venv("centos6_64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(false)
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("centos6_64")
-  end
-
   config.vm.define "xenial64" do |b|
     b.vm.box = "ubuntu/xenial64"
     b.vm.provider :virtualbox do |v|
@@ -420,17 +190,6 @@ Vagrant.configure(2) do |config|
     b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("xenial64")
   end
 
-  config.vm.define "trusty64" do |b|
-    b.vm.box = "ubuntu/trusty64"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1024 + $wmem
-    end
-    b.vm.provision "packages debianoid", :type => :shell, :inline => packages_debianoid
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_sys_venv("trusty64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(true)
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("trusty64")
-  end
-
   config.vm.define "stretch64" do |b|
     b.vm.box = "debian/stretch64"
     b.vm.provider :virtualbox do |v|
@@ -439,155 +198,11 @@ Vagrant.configure(2) do |config|
     b.vm.provision "packages debianoid", :type => :shell, :inline => packages_debianoid
     b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_sys_venv("stretch64")
     b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(true)
+    b.vm.provision "install pyinstaller", :type => :shell, :privileged => false, :inline => install_pyinstaller()
+    b.vm.provision "build binary with pyinstaller", :type => :shell, :privileged => false, :inline => build_binary_with_pyinstaller("stretch64")
     b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("stretch64")
   end
 
-  config.vm.define "jessie64" do |b|
-    b.vm.box = "debian/jessie64"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1024 + $wmem
-    end
-    b.vm.provision "packages debianoid", :type => :shell, :inline => packages_debianoid
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_sys_venv("jessie64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(true)
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("jessie64")
-  end
-
-  config.vm.define "wheezy32" do |b|
-    b.vm.box = "boxcutter/debian7-i386"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 768 + $wmem
-    end
-    b.vm.provision "packages prepare wheezy", :type => :shell, :inline => packages_prepare_wheezy
-    b.vm.provision "packages debianoid", :type => :shell, :inline => packages_debianoid
-    b.vm.provision "install pyenv", :type => :shell, :privileged => false, :inline => install_pyenv("wheezy32")
-    b.vm.provision "install pythons", :type => :shell, :privileged => false, :inline => install_pythons("wheezy32")
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_pyenv_venv("wheezy32")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(true)
-    b.vm.provision "install pyinstaller", :type => :shell, :privileged => false, :inline => install_pyinstaller()
-    b.vm.provision "build binary with pyinstaller", :type => :shell, :privileged => false, :inline => build_binary_with_pyinstaller("wheezy32")
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("wheezy32")
-  end
-
-  config.vm.define "wheezy64" do |b|
-    b.vm.box = "boxcutter/debian7"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1024 + $wmem
-    end
-    b.vm.provision "packages prepare wheezy", :type => :shell, :inline => packages_prepare_wheezy
-    b.vm.provision "packages debianoid", :type => :shell, :inline => packages_debianoid
-    b.vm.provision "install pyenv", :type => :shell, :privileged => false, :inline => install_pyenv("wheezy64")
-    b.vm.provision "install pythons", :type => :shell, :privileged => false, :inline => install_pythons("wheezy64")
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_pyenv_venv("wheezy64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(true)
-    b.vm.provision "install pyinstaller", :type => :shell, :privileged => false, :inline => install_pyinstaller()
-    b.vm.provision "build binary with pyinstaller", :type => :shell, :privileged => false, :inline => build_binary_with_pyinstaller("wheezy64")
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("wheezy64")
-  end
-
-  # OS X
-  config.vm.define "darwin64" do |b|
-    b.vm.box = "jhcook/yosemite-clitools"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1536 + $wmem
-      v.customize ['modifyvm', :id, '--ostype', 'MacOS1010_64']
-      v.customize ['modifyvm', :id, '--paravirtprovider', 'default']
-      # Adjust CPU settings according to
-      # https://github.com/geerlingguy/macos-virtualbox-vm
-      v.customize ['modifyvm', :id, '--cpuidset',
-                   '00000001', '000306a9', '00020800', '80000201', '178bfbff']
-      # Disable USB variant requiring Virtualbox proprietary extension pack
-      v.customize ["modifyvm", :id, '--usbehci', 'off', '--usbxhci', 'off']
-    end
-    b.vm.provision "packages darwin", :type => :shell, :privileged => false, :inline => packages_darwin
-    b.vm.provision "install pyenv", :type => :shell, :privileged => false, :inline => install_pyenv("darwin64")
-    b.vm.provision "fix pyenv", :type => :shell, :privileged => false, :inline => fix_pyenv_darwin("darwin64")
-    b.vm.provision "install pythons", :type => :shell, :privileged => false, :inline => install_pythons("darwin64")
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_pyenv_venv("darwin64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(true)
-    b.vm.provision "install pyinstaller", :type => :shell, :privileged => false, :inline => install_pyinstaller()
-    b.vm.provision "build binary with pyinstaller", :type => :shell, :privileged => false, :inline => build_binary_with_pyinstaller("darwin64")
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("darwin64")
-  end
-
-  # BSD
-  # note: the FreeBSD-10.3-RELEASE box needs "vagrant up" twice to start.
-  config.vm.define "freebsd64" do |b|
-    b.vm.box = "freebsd/FreeBSD-10.3-RELEASE"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1024 + $wmem
-    end
-    b.ssh.shell = "sh"
-    b.vm.provision "install system packages", :type => :shell, :inline => packages_freebsd
-    b.vm.provision "install pyenv", :type => :shell, :privileged => false, :inline => install_pyenv("freebsd")
-    b.vm.provision "install pythons", :type => :shell, :privileged => false, :inline => install_pythons("freebsd")
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_pyenv_venv("freebsd")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(true)
-    b.vm.provision "install pyinstaller", :type => :shell, :privileged => false, :inline => install_pyinstaller()
-    b.vm.provision "build binary with pyinstaller", :type => :shell, :privileged => false, :inline => build_binary_with_pyinstaller("freebsd")
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("freebsd")
-  end
-
-  config.vm.define "openbsd64" do |b|
-    b.vm.box = "openbsd60-64"  # note: basic openbsd install for vagrant WITH sudo and rsync pre-installed
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1024 + $wmem
-    end
-    b.ssh.shell = "sh"
-    b.vm.provision "packages openbsd", :type => :shell, :inline => packages_openbsd
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_sys_venv("openbsd64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(false)
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("openbsd64")
-  end
-
-  config.vm.define "netbsd64" do |b|
-    b.vm.box = "netbsd70-64"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1024 + $wmem
-    end
-    b.vm.provision "packages netbsd", :type => :shell, :inline => packages_netbsd
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_sys_venv("netbsd64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(false)
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("netbsd64")
-  end
-
-  # rsync on openindiana has troubles, does not set correct owner for /vagrant/borg and thus gives lots of
-  # permission errors. can be manually fixed in the VM by: sudo chown -R vagrant /vagrant/borg ; then rsync again.
-  config.vm.define "openindiana64" do |b|
-    b.vm.box = "openindiana/hipster"
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1536 + $wmem
-    end
-    b.vm.provision "packages openindiana", :type => :shell, :inline => packages_openindiana
-    b.vm.provision "build env", :type => :shell, :privileged => false, :inline => build_sys_venv("openindiana64")
-    b.vm.provision "install borg", :type => :shell, :privileged => false, :inline => install_borg(false)
-    b.vm.provision "run tests", :type => :shell, :privileged => false, :inline => run_tests("openindiana64")
-  end
-
-  config.vm.define "windows10" do |b|
-    b.vm.box = "Microsoft/EdgeOnWindows10"
-    b.vm.guest = :windows
-    b.vm.boot_timeout = 180
-    b.vm.graceful_halt_timeout = 120
-
-    b.ssh.shell = "sh -l"
-    b.ssh.username = "IEUser"
-    b.ssh.password = "Passw0rd!"
-    b.ssh.insert_key = false
-
-    b.vm.provider :virtualbox do |v|
-      v.memory = 1536 + $wmem
-      #v.gui = true
-    end
-
-    # fix permissions placeholder
-    b.vm.provision "fix perms", :type => :shell,  :privileged => false, :inline => "echo 'fix permission placeholder'"
-
-    b.vm.provision "packages cygwin", :type => :shell, :privileged => false, :inline => packages_cygwin("x86_64")
-    b.vm.provision :reload
-    b.vm.provision "cygwin install pip", :type => :shell, :privileged => false, :inline => install_cygwin_venv
-    b.vm.provision "cygwin build env", :type => :shell, :privileged => false, :inline => build_sys_venv("windows10")
-    b.vm.provision "cygwin install borg", :type => :shell, :privileged => false, :inline => install_borg(false)
-    b.vm.provision "cygwin run tests", :type => :shell, :privileged => false, :inline => run_tests("windows10")
-  end
+  # TODO: create more VMs with python 3.5+ and openssl 1.1.
+  # See branch 1.1-maint for a better equipped Vagrantfile (but still on py34 and openssl 1.0).
 end
diff --git a/docs/changes.rst b/docs/changes.rst
index 25909cf30..ec436b7e2 100644
--- a/docs/changes.rst
+++ b/docs/changes.rst
@@ -131,6 +131,16 @@ The best check that everything is ok is to run a dry-run extraction::
 Changelog
 =========
 
+Version 1.2.0dev0 (not released yet)
+------------------------------------
+
+Compatibility notes:
+
+- dropped support and testing for Python 3.4, minimum requirement is 3.5.0.
+  In case your OS does not provide Python >= 3.5, consider using our binary,
+  which does not need an external Python interpreter.
+
+
 Version 1.1.0rc1 (2017-07-24)
 -----------------------------
 
diff --git a/docs/development.rst b/docs/development.rst
index 37cc9ad68..e9868a1b9 100644
--- a/docs/development.rst
+++ b/docs/development.rst
@@ -182,7 +182,7 @@ Some more advanced examples::
   # verify a changed tox.ini (run this after any change to tox.ini):
   fakeroot -u tox --recreate
 
-  fakeroot -u tox -e py34  # run all tests, but only on python 3.4
+  fakeroot -u tox -e py35  # run all tests, but only on python 3.5
 
   fakeroot -u tox borg.testsuite.locking  # only run 1 test module
 
@@ -315,7 +315,7 @@ Checklist:
 - check version number of upcoming release in ``CHANGES.rst``
 - verify that ``MANIFEST.in`` and ``setup.py`` are complete
 - ``python setup.py build_usage ; python setup.py build_man`` and
-  commit (be sure to build with Python 3.4 or 3.5 as Python 3.6 added `more
+  commit (be sure to build with Python 3.5 as Python 3.6 added `more
   guaranteed hashing algorithms
   <https://github.com/borgbackup/borg/issues/2123>`_)
 - tag the release::
diff --git a/docs/installation.rst b/docs/installation.rst
index 353254c38..683560fc7 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -136,7 +136,7 @@ Dependencies
 To install |project_name| from a source package (including pip), you have to install the
 following dependencies first:
 
-* `Python 3`_ >= 3.4.0, plus development headers. Even though Python 3 is not
+* `Python 3`_ >= 3.5.0, plus development headers. Even though Python 3 is not
   the default Python version on most systems, it is usually available as an
   optional install.
 * OpenSSL_ >= 1.0.0, plus development headers.
@@ -181,7 +181,7 @@ group, log out and log in again.
 Fedora / Korora
 +++++++++++++++
 
-.. todo:: Add zeromq
+.. todo:: Add zeromq, use python 3.5 or 3.6
 
 Install the dependencies with development headers::
 
@@ -196,7 +196,7 @@ Install the dependencies with development headers::
 openSUSE Tumbleweed / Leap
 ++++++++++++++++++++++++++
 
-.. todo:: Add zeromq
+.. todo:: Add zeromq, use python 3.5 or 3.6
 
 Install the dependencies automatically using zypper::
 
@@ -213,7 +213,7 @@ Alternatively, you can enumerate all build dependencies in the command line::
 Mac OS X
 ++++++++
 
-.. todo:: Add zeromq
+.. todo:: Add zeromq, use python 3.5 or 3.6
 
 Assuming you have installed homebrew_, the following steps will install all the
 dependencies::
@@ -231,7 +231,7 @@ FUSE for OS X, which is available as a pre-release_.
 FreeBSD
 ++++++++
 
-.. todo:: Add zeromq
+.. todo:: Add zeromq, use python 3.5 or 3.6
 
 Listed below are packages you will need to install Borg, its dependencies,
 and commands to make FUSE work for using the mount command.
@@ -264,7 +264,7 @@ Cygwin
     Running under Cygwin is experimental and has only been tested with Cygwin
     (x86-64) v2.5.2. Remote repositories are known broken, local repositories should work.
 
-.. todo:: Add zeromq
+.. todo:: Add zeromq, use python 3.5 or 3.6
 
 Use the Cygwin installer to install the dependencies::
 
diff --git a/docs/usage_general.rst.inc b/docs/usage_general.rst.inc
index 3c6191438..8a20275c7 100644
--- a/docs/usage_general.rst.inc
+++ b/docs/usage_general.rst.inc
@@ -215,7 +215,7 @@ Please note:
   (e.g. mode 600, root:root).
 
 
-.. _INI: https://docs.python.org/3.4/library/logging.config.html#configuration-file-format
+.. _INI: https://docs.python.org/3.5/library/logging.config.html#configuration-file-format
 
 .. _file-systems:
 
diff --git a/setup.py b/setup.py
index 43936623e..d73fa089f 100644
--- a/setup.py
+++ b/setup.py
@@ -764,7 +764,7 @@ setup(
     license='BSD',
     platforms=['Linux', 'MacOS X', 'FreeBSD', 'OpenBSD', 'NetBSD', ],
     classifiers=[
-        'Development Status :: 4 - Beta',
+        'Development Status :: 2 - Pre-Alpha',
         'Environment :: Console',
         'Intended Audience :: System Administrators',
         'License :: OSI Approved :: BSD License',
@@ -775,7 +775,6 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Topic :: Security :: Cryptography',
diff --git a/src/borg/archiver.py b/src/borg/archiver.py
index 4dc5dacce..7d27e8c64 100644
--- a/src/borg/archiver.py
+++ b/src/borg/archiver.py
@@ -2022,11 +2022,11 @@ class Archiver:
 
         {now}
             The current local date and time, by default in ISO-8601 format.
-            You can also supply your own `format string <https://docs.python.org/3.4/library/datetime.html#strftime-and-strptime-behavior>`_, e.g. {now:%Y-%m-%d_%H:%M:%S}
+            You can also supply your own `format string <https://docs.python.org/3.5/library/datetime.html#strftime-and-strptime-behavior>`_, e.g. {now:%Y-%m-%d_%H:%M:%S}
 
         {utcnow}
             The current UTC date and time, by default in ISO-8601 format.
-            You can also supply your own `format string <https://docs.python.org/3.4/library/datetime.html#strftime-and-strptime-behavior>`_, e.g. {utcnow:%Y-%m-%d_%H:%M:%S}
+            You can also supply your own `format string <https://docs.python.org/3.5/library/datetime.html#strftime-and-strptime-behavior>`_, e.g. {utcnow:%Y-%m-%d_%H:%M:%S}
 
         {user}
             The user name (or UID, if no name is available) of the user running borg.
diff --git a/src/borg/helpers.py b/src/borg/helpers.py
index 2094c8652..d5a803db5 100644
--- a/src/borg/helpers.py
+++ b/src/borg/helpers.py
@@ -1967,71 +1967,9 @@ def consume(iterator, n=None):
         # advance to the empty slice starting at position n
         next(islice(iterator, n, n), None)
 
-# GenericDirEntry, scandir_generic (c) 2012 Ben Hoyt
-# from the python-scandir package (3-clause BSD license, just like us, so no troubles here)
-# note: simplified version
-
-
-class GenericDirEntry:
-    __slots__ = ('name', '_scandir_path', '_path')
-
-    def __init__(self, scandir_path, name):
-        self._scandir_path = scandir_path
-        self.name = name
-        self._path = None
-
-    @property
-    def path(self):
-        if self._path is None:
-            self._path = os.path.join(self._scandir_path, self.name)
-        return self._path
-
-    def stat(self, follow_symlinks=True):
-        assert not follow_symlinks
-        return os.stat(self.path, follow_symlinks=follow_symlinks)
-
-    def _check_type(self, type):
-        st = self.stat(False)
-        return stat.S_IFMT(st.st_mode) == type
-
-    def is_dir(self, follow_symlinks=True):
-        assert not follow_symlinks
-        return self._check_type(stat.S_IFDIR)
-
-    def is_file(self, follow_symlinks=True):
-        assert not follow_symlinks
-        return self._check_type(stat.S_IFREG)
-
-    def is_symlink(self):
-        return self._check_type(stat.S_IFLNK)
-
-    def inode(self):
-        st = self.stat(False)
-        return st.st_ino
-
-    def __repr__(self):
-        return '<{0}: {1!r}>'.format(self.__class__.__name__, self.path)
-
-
-def scandir_generic(path='.'):
-    """Like os.listdir(), but yield DirEntry objects instead of returning a list of names."""
-    for name in sorted(os.listdir(path)):
-        yield GenericDirEntry(path, name)
-
-
-try:
-    from os import scandir
-except ImportError:
-    try:
-        # Try python-scandir on Python 3.4
-        from scandir import scandir
-    except ImportError:
-        # If python-scandir is not installed, then use a version that is just as slow as listdir.
-        scandir = scandir_generic
-
 
 def scandir_inorder(path='.'):
-    return sorted(scandir(path), key=lambda dirent: dirent.inode())
+    return sorted(os.scandir(path), key=lambda dirent: dirent.inode())
 
 
 def clean_lines(lines, lstrip=None, rstrip=None, remove_empty=True, remove_comments=True):
diff --git a/src/borg/remote.py b/src/borg/remote.py
index d131a8266..1cc455c2e 100644
--- a/src/borg/remote.py
+++ b/src/borg/remote.py
@@ -1,5 +1,4 @@
 import errno
-import fcntl
 import functools
 import inspect
 import json
@@ -190,15 +189,9 @@ class RepositoryServer:  # pragma: no cover
         stdin_fd = sys.stdin.fileno()
         stdout_fd = sys.stdout.fileno()
         stderr_fd = sys.stdout.fileno()
-        # Make stdin non-blocking
-        fl = fcntl.fcntl(stdin_fd, fcntl.F_GETFL)
-        fcntl.fcntl(stdin_fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
-        # Make stdout blocking
-        fl = fcntl.fcntl(stdout_fd, fcntl.F_GETFL)
-        fcntl.fcntl(stdout_fd, fcntl.F_SETFL, fl & ~os.O_NONBLOCK)
-        # Make stderr blocking
-        fl = fcntl.fcntl(stderr_fd, fcntl.F_GETFL)
-        fcntl.fcntl(stderr_fd, fcntl.F_SETFL, fl & ~os.O_NONBLOCK)
+        os.set_blocking(stdin_fd, False)
+        os.set_blocking(stdout_fd, True)
+        os.set_blocking(stderr_fd, True)
         unpacker = get_limited_unpacker('server')
         while True:
             r, w, es = select.select([stdin_fd], [], [], 10)
@@ -557,9 +550,9 @@ class RemoteRepository:
         self.stdin_fd = self.p.stdin.fileno()
         self.stdout_fd = self.p.stdout.fileno()
         self.stderr_fd = self.p.stderr.fileno()
-        fcntl.fcntl(self.stdin_fd, fcntl.F_SETFL, fcntl.fcntl(self.stdin_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
-        fcntl.fcntl(self.stdout_fd, fcntl.F_SETFL, fcntl.fcntl(self.stdout_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
-        fcntl.fcntl(self.stderr_fd, fcntl.F_SETFL, fcntl.fcntl(self.stderr_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
+        os.set_blocking(self.stdin_fd, False)
+        os.set_blocking(self.stdout_fd, False)
+        os.set_blocking(self.stderr_fd, False)
         self.r_fds = [self.stdout_fd, self.stderr_fd]
         self.x_fds = [self.stdin_fd, self.stdout_fd, self.stderr_fd]
 
diff --git a/tox.ini b/tox.ini
index 2e04bf2e7..8fb3f31bd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,7 +2,7 @@
 # fakeroot -u tox --recreate
 
 [tox]
-envlist = py{34,35,36},flake8
+envlist = py{35,36},flake8
 
 [testenv]
 deps =