Categories: XenServer, Alike v3, Alike v4

Introduction

Disk and Memory backups allow Alike to protect both the VMs disk state, as well as its running memory, allowing it to restore a system to an active running state. This powerful feature provides a compelling method for protecting transactionally sensitive systems, without the need for a quiesced or similar protection. Alike leverages XenServer’s memory and disk snapshot technology (checkpointing) for Enhanced Backup jobs.

The power of this technique is that it allows you to restore your virtual machines directly back to a running state, as if resuming from a suspension state—with all the applications and services still running from the time of the backup. Furthermore, the VMs experience no downtime during the snapshot/backup procedure.

Requirements

In order to utilize Alike’s Memory State Backup feature, you must have a valid license for your hypervisor host. For versions of XenServer prior to 6.2, Platinum or Enterprise editions were needed. As of XenServer 6.2, all users are supported. Additionally, XCP based systems are fully supported.

All guest operating systems are supported, so long as they have the XenServer guest tools installed. Please note, the quiesced tools are not required– only the standard guest installer is needed.

Configuration

Configuration of memory state backups is simple. In the backup job configuration wizard, just select the “Disk & memory” under snapshot options. Then, all VMs in that backup job will have both their disk data and memory automatically protected. If any VM is not in a running state during the backup job, or if the memory snapshot fails for any reason, they will protected using standard XenServer snapshots.

Addendum

A further attribute of this feature is that any virtual machine that is suspended at the time of backup, will be detected and automatically have its memory state protected in the backup job, regardless of the hypervisor licensing. In this way, it is possible acquire a memory state backup from even the XenServer Free edition.

Final Notes

• The contents of the VMs memory is deduplicated and encrypted during backup
• The memory state backups are 100% compatible with all forms of restore- full, file level, OVA export, etc.