GitHub user daviftorres edited a discussion: What does Snapshots, Backups, and Incremental Snapshots mean in CloudStack
Dear CloudStack fellows, Recently, Lucian mentioned the new 4.22 feature that "enables incremental volume snapshots" (https://www.youtube.com/watch?v=ZZi3CpX6u2I&t=680s). I would like to open a discussion so we can collaboratively clarify the different types of snapshots and backups that CloudStack currently supports, and how they actually work. First, there is an important conceptual distinction between snapshots and backups: - Snapshots are primarily point-in-time rollback mechanisms. They rely on layers of changes, and usually do not involve copying the full dataset. - Backups are copies of data intended for restore, retention, and disaster recovery. >From there, things become more nuanced: - A full backup is a complete bit-for-bit copy of the original data. - An incremental backup contains only the changes since the last backup, which helps save space and time. - Incremental backups often rely on snapshot mechanisms to track changes. - A synthetic full backup can later be built by applying all incremental layers on top of the initial full backup. Where I am still unclear is how these concepts map into the Apache CloudStack ecosystem: - Snapshots in CloudStack are stored on Secondary Storage alongside templates and images, which makes them feel closer to “copies” than pure rollback layers. - NAS Backup appears similar to snapshots, but sends a volume copy to a separate repository. For the sake of simplicity, I am focusing first on KVM + NFS but it is not limited to. These distinctions matter, especially when SLAs, compliance requirements, and operational policies treat snapshots and backups very differently. I encourage others to share their understanding and explanations. My goal is to consolidate this discussion and translate it into clearer documentation afterward. Regards, Davi Torres GitHub link: https://github.com/apache/cloudstack/discussions/12475 ---- This is an automatically sent email for [email protected]. To unsubscribe, please send an email to: [email protected]
