Project Overview
The Availability Suite is based on the Sun StorageTek, a Solaris 8, 9 & 10, unbundled product set, consisting of Instant Image (II) and Network Data Replicator (SNDR). Availability Suite was developed to interpose itself on the I/O stack of a block device, providing a filter driver framework with the means to intercept any I/O originating from an upstream file system, database or application layer I/O. This framework provided the means for Availability Suite to support snapshot and remote replication data services for UFS, QFS, VxFS, and more recently the ZFS file system, plus various databases like Oracle, Sybase and PostgreSQL, and also application I/Os. By providing a filter driver at this point in the Solaris I/O stack, it allows for any number of data services to be implemented, without regard to the underlying block storage that they will be configured on.Today, as a snapshot and/or replication solution, the framework allows both the source and destination block storage device to not only differ in physical characteristics (DAS, Fibre Channel, iSCSI, etc.), but also logical characteristics such as in RAID type, volume managed storage (i.e., SVM, VxVM), lofi, zvols, even ram disks.
Community Involvement
By providing this filter-driver framework, two working filter drivers (II & SNDR), and an extensive collection of supporting software and utilities, it is envisioned that those individuals and companies that adopt OpenSolaris as a viable storage platform, will also utilize and enhance the existing II & SNDR data services, plus have offered to them the means in which to develop their own block-based filter driver(s), further enhancing the use and adoption on OpenSolaris.A very timely example that is very applicable to Availability Suite and the OpenSolaris community, is the recent announcement of the Project Proposal: lofi [ compression & encryption ]. By leveraging both the Availability Suite and the lofi OpenSolaris projects, it would be highly probable to not only offer compression & encryption to lofi devices (as already proposed), but by collectively leveraging these two projects, creating the means to support file systems, databases and applications, across all block-based storage devices.
Since Availability Suite has strong technical ties to storage, please check out the email discussions for this project. BTW, you can also find a complete set of Availability Suite administration guides there too.