How do I take an snapshot or backup without filesystem freezing? Print

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Our KVM Cloud images have qemu-guest-agent installed and enabled by default. This allows our backend to interact with your instance in a variety of ways. For example, during the snapshot process, libvirt will tell qemu-guest-agent to freeze (quiesce) your instance filesystem. The instance remains online, but I/O is suspended until the snapshot is ready to upload to our image store. This method is ideal for data consistency, but can cause significant functional downtime for instances with lots of data and/or activity. As such, you may prefer to bypass filesystem freezing for your snapshots/backups. To do so, simply stop qemu-guest-agent prior to taking a snapshot.

Steps

  1. SSH into your instance
  2. Run command: systemctl stop qemu-guest-agent
  3. Create a snapshot from the Cloud Control Panel

We recommend restarting qemu-guest-agent (systemctl start qemu-guest-agent) when the snapshot is done. However, if you'd prefer to leave qemu-guest-agent off permanently (for future snapshots, automated backups, etc.), you can disable it with systemctl disable qemu-guest-agent and/or remove it with apt remove qemu-guest-agent (Debian/Ubuntu) or yum remove qemu-guest-agent (CentOS).

Notes

The steps above apply to any instance launched from our KVM Cloud images after September 16, 2019. Contact us via support ticket if you want this ability enabled for instances launched before then.

This does NOT apply to instances launched from ISOs or any image that does not have qemu-guest-agent enabled.


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