Instance Snapshots & Backups

Overview

Xloud Compute provides two complementary data protection mechanisms for virtual machine instances. Instance snapshots capture the full disk state as a reusable image, and volume backups archive attached block storage to object storage. Together they give you point-in-time recovery, pre-change safety nets, and a reliable path for cloning and migrating workloads.

Prerequisites

A running or shutoff instance
Sufficient quota in the Image Service (for snapshots) and Object Storage (for backups)
Volumes attached to the instance if you want volume-level backups

Instance Snapshots

An instance snapshot saves the entire disk state of a running or shutoff VM as an image in the Xloud Image Service. You can boot new instances from the snapshot or use it as a restore point.

Dashboard
CLI

Open the instance actions menu

Navigate to Compute → Instances, find your instance, and click Create Snapshot from the actions dropdown.

Name the snapshot

Enter a descriptive name. The snapshot is stored in the Image Service under your project.

Use a naming convention like <instance-name>-YYYYMMDD-pre-<change> so snapshots are easy to identify and sort.

Wait for completion

The instance status changes to IMAGE_SNAPSHOT while the snapshot is being captured. For large disks this may take several minutes.

The snapshot appears under Compute → Images with status Active when complete.

Create an instance snapshot

openstack server image create \
  --name my-instance-snap-20250315 \
  my-instance

Monitor snapshot status

openstack image show my-instance-snap-20250315 \
  --format value -c status
# Returns: saving → queued → active

List all snapshots

openstack image list \
  --property image_type=snapshot \
  --status active

Restore from Snapshot

Boot a new instance from any saved snapshot to restore the workload or create a clone:

Dashboard
CLI

Navigate to Compute → Images, find the snapshot, and click Launch Instance. The instance boots with the exact disk state from the snapshot.

Boot from snapshot

openstack server create \
  --flavor m1.medium \
  --image my-instance-snap-20250315 \
  --network private \
  --key-name my-keypair \
  restored-instance

Volume Backups

For instances with attached persistent volumes, use block storage backups to archive volume data to object storage independently of the instance lifecycle.

Dashboard
CLI

Navigate to Block Storage → Volumes, select a volume, and click Create Backup from the actions menu. Enter a name and optionally select an existing snapshot as the source.

Create a full volume backup

openstack volume backup create \
  --name my-vol-backup-20250315 \
  my-data-volume

Restore a volume backup

openstack volume backup restore \
  my-vol-backup-20250315 \
  my-data-volume

Volume backups are stored in Object Storage and persist independently of the source volume. They can be restored to any volume in the same project.

Snapshot Management

Automate snapshots with a cron job

Use the CLI in a scheduled task to create regular snapshots:

Weekly snapshot script

#!/bin/bash
INSTANCE="web-server-01"
DATE=$(date +%Y%m%d)
source ~/openrc.sh

openstack server image create \
  --name "${INSTANCE}-weekly-${DATE}" \
  "${INSTANCE}"

# Keep only last 4 weekly snapshots
openstack image list \
  --property image_type=snapshot \
  --format value -c ID -c Name | \
  grep "${INSTANCE}-weekly" | \
  sort -k2 | head -n -4 | \
  awk '{print $1}' | \
  xargs -r openstack image delete

Share snapshots across projects

Snapshots are private by default. To share with another project:

Make snapshot shared

openstack image set --shared my-instance-snap-20250315

openstack image add project \
  my-instance-snap-20250315 \
  <target-project-id>

Convert snapshot to a base image

After validating a snapshot as a stable base, set its visibility to public (admin only) or promote it as a project-shared image:

Promote to shared project image

openstack image set \
  --shared \
  --property description="Hardened Ubuntu 22.04 base" \
  my-instance-snap-20250315

Snapshot vs Backup — Comparison

Feature	Instance Snapshot	Volume Backup
What is captured	Full instance disk (root + ephemeral)	Single attached volume
Storage location	Image Service	Object Storage
Used to	Boot new instances, clone, restore	Restore volume data
Bootable	Yes	No (restore to volume first)
Incremental support	No (always full)	Yes (incremental after first)
Cross-project restore	Yes (with share)	No (project-scoped)

Snapshots capture disk state at a point in time. For application-consistent backups of databases or stateful services, quiesce writes (or use application-level dumps) before creating a snapshot.

Application-Consistent Snapshots

Xloud-Developed — This capability is developed by Xloud and ships with XAVS / XPCI.

Standard snapshots are crash-consistent — they capture whatever is on disk at that instant. Application-consistent snapshots go further by coordinating with the guest operating system to flush buffers and freeze filesystems before the snapshot is taken.

Feature	Description
Filesystem freeze (Linux)	The XAVS Guest Agent issues `fsfreeze --freeze` to quiesce all mounted filesystems before the snapshot, then thaws automatically after
VSS integration (Windows)	On Windows guests, the agent triggers a Volume Shadow Copy Service (VSS) snapshot for application-level consistency
Strict quiesce mode	Set `os_require_quiesce=yes` on the image metadata to fail the snapshot if the XAVS Guest Agent is not responding — prevents silently falling back to crash-consistent snapshots
Custom pre/post hooks	Configure pre-snapshot and post-snapshot scripts inside the guest (e.g., `pg_start_backup` / `pg_stop_backup` for PostgreSQL) for database-level consistency
Dashboard status indicators	The Dashboard displays live XAVS Guest Agent connectivity status and consistency badges (application-consistent vs. crash-consistent) on each snapshot

Install the XAVS Guest Agent on all production instances. Without the agent, snapshots fall back to crash-consistent mode, which may require filesystem repair (fsck) or database recovery on restore. See File-Level Restore for browsing snapshot contents without a full restore.

Agentless File-Level Restore

Xloud-Developed — This capability is developed by Xloud and ships with XAVS / XPCI.

Xloud provides agentless file-level restore directly from instance snapshots — browse directories, preview files, and download individual files or multi-file ZIP archives without restoring the entire virtual machine. This is a major competitive differentiator: no in-VM agent is required, and the feature works even on snapshots of decommissioned or deleted instances.

Capability	Description
Partition detection	Automatically detects all partitions within the snapshot image (Linux ext4/xfs/btrfs, Windows NTFS)
Directory navigation	Browse the full filesystem tree from the Dashboard — navigate folders, view file sizes and timestamps
Single file download	Download any individual file directly from the snapshot to your local machine
Multi-file ZIP archive	Select multiple files or directories and download them as a single ZIP archive
No agent dependency	Works without any software inside the guest — operates at the block device layer on the storage backend

Access file-level restore from the Compute / Images panel in the Dashboard. Select any snapshot and click Browse Files to open the file browser.

File-level restore is ideal for recovering configuration files, database dumps, or application logs from snapshots without the time and resource cost of booting a full restored instance.

Next Steps

Image Service

Manage, share, and convert snapshot images in the Xloud Image catalog

Block Storage Snapshots

Volume-level snapshots for persistent block storage attached to instances

Disaster Recovery

Automated failover and recovery for mission-critical instances

Instance Launch

Boot new instances from snapshots or base images

Core Services

Other Services

Instance Snapshots & Backups

Overview

Instance Snapshots

Open the instance actions menu

Name the snapshot

Wait for completion

Restore from Snapshot

Volume Backups

Snapshot Management

Snapshot vs Backup — Comparison

Application-Consistent Snapshots

Agentless File-Level Restore

Next Steps

Image Service

Block Storage Snapshots

Disaster Recovery

Instance Launch

Core Services

Other Services

​Overview

​Instance Snapshots

Open the instance actions menu

Name the snapshot

Wait for completion

​Restore from Snapshot

​Volume Backups

​Snapshot Management

​Snapshot vs Backup — Comparison

​Application-Consistent Snapshots

​Agentless File-Level Restore

​Next Steps

Image Service

Block Storage Snapshots

Disaster Recovery

Instance Launch

Overview

Instance Snapshots

Restore from Snapshot

Volume Backups

Snapshot Management

Snapshot vs Backup — Comparison

Application-Consistent Snapshots

Agentless File-Level Restore

Next Steps