Importance Of Cluster Data Protection

In addition to ensuring the availability of ZFS pools and data protection, bulletproof data fencing capabilities are needed to protect the physical data from potential split-brain scenarios. For example, sometimes a server, or network access, may freeze for a few moments and recover during or after a service failover, leading to the potentially disastrous scenario of storage corruption by data pools being written to by two or more servers at the same time.

It is also important to provide high availability and integrity of associated file and block services (e.g. NFS, SMB, iSCSI, ALUA), to maintain connections for virtualized environments, to ensure replication and snapshot capabilities and backup schedules services are maintained, and so on.

More complex storage topologies may also involve a large number of ZFS pools serviced across multiple servers meaning a simple active/passive (two node) configuration is not possible. Simple high availability solutions reliant on network heartbeats may not accommodate stretched storage topologies where servers physically reside in different locations or include a remote replicated third node in a backup or disaster recovery site.

ZFS High Availability Considerations

High Availability Considerations for ZFS:

  • ZFS is not a clustered file system
  • No pool import protection
  • No inherent data fencing mechanisms
  • Varying ZFS pool import times
  • Managing ZFS cache devices
  • File & Block service failover time and timeout
  • Network connectivity and failover
  • Failover management framework

Bringing these enterprise-grade high availability features to a critical ZFS storage deployment also requires deploying a bulletproof and proven high availability solution; this is where High-Availability.com's RSF-1 for ZFS comes in.

RSF-1 for ZFS

RSF-1 for ZFS allows multiple ZFS pools to be managed across multiple servers providing High Availability for both block and file services beyond a traditional two-node Active/Active or Active/Passive topology. With RSF-1 for ZFS, highly available ZFS services can also span beyond the single data centre.

Illustration showing the benefits of combining ZFS and RSF-1

RSF-1 for ZFS storage is therefore more than a Disaster Recovery solution failing back to a previous snapshot point-in-time but provides real-time failover in the event of failure or disaster where data is always up-to-date and failover transparent to system users. It is also a sophisticated system administration tool that allows for controlled management of storage services to facilitate smooth and seamless system upgrades and maintenance.

RSF-1 for ZFS also supports shared-nothing cluster topology whereby the underlying ZFS storage does not need to be physically shared between cluster nodes, but instead implements ZFS snapshot and replication technologies to maintain data integrity between cluster nodes.

Managed by a standalone GUI, command line interface and a rich API, RSF-1 for ZFS can also be easily seamlessly integrated into other management administration toolsets and control panels.

RSF-1 for ZFS Highlights

  • Multiple server, multiple pool failover support
  • File and block service failover
  • Multiple heartbeat mechanisms
  • Bulletproof data fencing
  • ZFS-specific fast failover
  • Stretch cluster capability
  • Shared storage and Shared-nothing topologies
  • API integration framework
  • GUI and CLI administration toolset
  • Wide variety of Operating System support

Why you need RSF-1 for ZFS Enterprise Deployment

ZFS is a mature enterprise-proven storage technology that is growing in open-source popularity and deployments, due to it's advanced and innovative rich feature set. It's notable innovative features include: data consistency and integrity, copy-on-write, snapshots, infinite scalability, inline data compression and deduplication. It's limitations however are that some of these advanced features require more server memory than other storage technologies, it is not a clustered, or distributed filesystem, and therefore cannot scale-out beyond a single server.

For scale-out, this typically means having to include other distributed filesystems on top of ZFS, such as lustre or Gluster. However, scale-out can also be achieved using High Availability Clusters such as RSF-1 for ZFS, that allows multiple servers to manage multiple ZFS pools and provide seamless failover within the cluster in the event of server failure, using both shared and shared-nothing topologies.

At the heart of the RSF-1 for ZFS solution is a mature and stable enterprise class high availability product that has provided Enterprise-grade High-Availability ZFS Storage services to thousands of mission-critical deployments worldwide since 2009. RSF-1 for ZFS has been licensed by a number of leading and innovative storage companies that have built their own storage solutions around ZFS but required advanced High Availability capability for enterprise deployments.

Clustering