Debian Jessie availability and a new default Miniserver kernel

Since the release of Debian Jessie, we've been working hard to build and thoroughly test a Jessie image for our Miniserver platform. As of today we're pleased to announce that it is available for new Miniservers, and also for re-images.

Jessie relies on features of a very recent linux kernel so it required a new kernel build. As we aim to offer the most stable platform possible, the logical choice was to use the longterm 3.18.x branch; after several weeks of stability testing we have today made 3.18.12 available on all hosts as the default kernel.

To enable the new kernel for your Miniserver, you'll need to reboot your server from the Memset control panel; how to carry this out is detailed here under the Manual Reboots section.

Please note that rebooting via SSH or WHM isn't sufficient as it won't pull in the new kernel, it must be done using Memset's control panel reboot method.

Upgrading from Wheezy to Jessie

Having tested this internally, the upgrade is fairly simple, although there are a couple of potential stumbling blocks (see Jessie Upgrade Caveats below).

It is strongly advised that you read and understand the Jessie upgrade notes prior to carrying out the upgrade. Once you are happy with this, the steps below outline the basic procedure:

  • First, reboot your Miniserver from your Memset control panel.
  • Ensure your server is up to date:
    apt-get update
    apt-get upgrade
    apt-get dist-upgrade
    
  • Edit sources.list to use Jessie:
    sed -i 's/wheezy/jessie/g' /etc/apt/sources.list
    
  • Upgrade packages:
    apt-get update
    apt-get upgrade
    
  • Upgrade the OS:
    apt-get dist-upgrade
    
  • Finally, reboot:
    shutdown -r now
    

Jessie Upgrade Caveats

Firstly, the default behaviour for SSH under Jessie is to disable password access to the root account – you will be prompted about this during the upgrade. If you don't use SSH keys then be sure to say no to this new behaviour (although we would always recommend key-based authentication over passwords for security reasons).

The second potential issue is related to how your Miniserver is configured on boot – under Wheezy an init script named miniserver-configure runs to set networking, hostname etc.

As Jessie uses systemd it may not run the old service early enough in the boot process to be effective, so we would recommend using the unit file available here - this must be placed in /etc/systemd/system/.

Next, disable the old init script with update-rc.d -f miniserver-configure remove. To avoid confusion, the init script must then be removed with rm /etc/init.d/miniserver-configure.

Finally, enable the systemd unit with systemctl enable miniserver-configure.service.

It is recommended that you ensure you can access your Miniserver via MemShell SSH prior to beginning the upgrade.

As always, if you need our help then please submit a ticket to our Support team.

Posted May 2015 by Simon Weald , in Ops

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