VMware is releasing VSAN 6.2, the third major release of VSAN since its introduction in August of 2014. (Like other VMware companion products, the release number is tied to the vSphere release number it is associated with.) This release gives vSphere most if not all of the major features found in other hyperconverged infrastructure products.
The initial release (5.1) introduced the basic concept of a pool of storage consisting of a cluster of HDDs that were physically resident in a vSphere host, and it used SSDs as a read only cache. In 6.0 the added support for an all-flash configuration, a 64-node cluster, snapshots and clones, rack awareness and a 100% increase in performance. VSAN 6.1 added support for stretch cluster and a 5-minute RPO, along with a two-node ROBO configuration and more health monitoring.
Only six months later, VMware is now releasing VSAN 6.2 and now advertising vSphere as a hyperconverged infrastructure (HCI) product. While vSphere was always a component of HCI architectures, the lack of the storage component caused it to fall short of being a full HCI offering. This changes with VSAN 6.2.
The first big feature added in 6.2 is deduplication and compression. While this is technically two different features, they are bundled together as a single offering and are enabled cluster-wide. In other words, customers either use both dedupe and compression or neither. For performance reasons, this feature is only enabled in all flash configurations, which are comprised of a performance layer of high-speed SSDs, and a capacity layer of less expensive SSDs. All data is written to the performance layer first and the selectively deduped and compressed to the capacity layer based on usage. Hot and recently used data is left in its native form, with the rest of it being deduped and compressed and written to the capacity layer. Since all data is written to the performance layer first, this does not qualify to be called inline dedupe; therefore, VMware chose to call it nearline dedupe.
VSAN 6.2 also added support for RAID levels 5 and 6 including checksums to reduce any chances of silent data corruption. It also adds support for IPv6 and some QOS features.
Watch VMware’s announcement of VMware 6.2 features here:
StorageSwiss Take
VSAN has come a long way since it was released around two years ago. It now seems to be a very feature-rich alternative to clustered storage for some environments. There are probably still environments that will have performance or other requirements that will not be met by this product, but there’s a very large segment of the market that should be very happy with both VSAN performance and feature set.
W. Curtis Preston (aka Mr. Backup) is an expert in backup & recovery systems; a space he has been working in since 1993. He has written three books on the subject, Backup & Recovery, Using SANs and NAS, and Unix Backup & Recovery. Mr. Preston is a writer and has spoken at hundreds of seminars and conferences around the world. Preston’s mission is to arm today’s IT managers with truly unbiased information about today’s storage industry and its products.
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