Longhorn implements distributed block storage using containers and microservices. Longhorn creates a dedicated storage controller for each block device volume and synchronously replicates the volume across multiple replicas stored on multiple nodes. The storage controller and replicas are themselves orchestrated using Kubernetes.
Features
- Enterprise-grade distributed block storage with no single point of failure
- Incremental snapshot of block storage
- Backup to secondary storage (NFS or S3-compatible object storage) built on efficient change block detection
- Recurring snapshots and backups
- Automated, non-disruptive upgrades. You can upgrade the entire Longhorn software stack without disrupting running storage volumes.
- An intuitive GUI dashboard
In the past, ITOps and DevOps have found it hard to add replicated storage to Kubernetes clusters. As a result many non-cloud-hosted Kubernetes clusters don’t support persistent storage. External storage arrays are non-portable and can be extremely expensive.
Longhorn delivers simplified, easy to deploy and upgrade, 100% open source, cloud-native persistent block storage without the cost overhead of open core or proprietary alternatives.
Velero is a backup and restore solution for Kubernetes, that can be used to take backups and restore them in case of loss but also for migrating to other clusters.
Authors:
Jie Yu <jie@mesosphere.io> (@jieyu)
Saad Ali <saadali@google.com> (@saad-ali)
James DeFelice <james@mesosphere.io> (@jdef)
container-storage-interface-working-group@googlegroups.comThe Kubernetes implementation of the Container Storage Interface (CSI) has been promoted to GA in the Kubernetes v1.13 release. Support for CSI was introduced as alpha in Kubernetes v1.9 release, and promoted to beta in the Kubernetes v1.10 release.
The GA milestone indicates that Kubernetes users may depend on the feature and its API without fear of backwards incompatible changes in future causing regressions. GA features are protected by the Kubernetes deprecation policy.