Microsoft has made several changes to Storage Spaces Direct with the launch of Windows Server 2019. You can now...
create a storage pool with as much as 400 TB of raw capacity per server and as much as 4 petabytes of raw capacity per cluster -- four times the amounts available to Windows Server 2016. Plus, you can create up to 64 volumes, each with a maximum size of 64 TB, doubling the capacities supported by its predecessor.
Microsoft Storage Spaces Direct makes use of commodity hardware to create highly available software-defined storage that's scalable and less expensive than a SAN. The new version of Storage Spaces Direct also more than doubles the performance of its mirror-accelerated parity feature, which lets you create volumes that are part mirror and part parity, such as mixing different RAID levels. Storage Spaces Direct has also added native support for persistent memory modules, including Intel's Optane DC persistent memory, boosting performance even more.
Nested resiliency for two-node clusters
Another addition in Storage Spaces Direct is nested resiliency for two-node clusters, such as those found in edge hyper-converged systems. This feature makes it possible to survive two hardware failures at once, even if one server node goes down and a drive fails on the other node.
You can also now use a USB flash drive as a witness for two-node clusters, rather than having to implement an additional server or virtual machine for the witness. In this way, if a server goes down and then comes back up, the USB drive knows which server has the most up-to-date data.
With the new Microsoft Storage Spaces Direct, you can also implement deduplication and compression for volumes based on the Resilient File System, making it possible to store up to 10 times more data per volume. And you can manually delimit volume allocations to increase fault tolerance, although this requires more management time.
Windows Admin Center support
Microsoft has also added support for Storage Spaces Direct to Windows Admin Center, a free on-premises application for managing servers, clusters, hyper-converged infrastructures and Windows 10 computers. Windows Admin Center now includes a purpose-built dashboard for managing and monitoring Storage Spaces Direct volumes for both Windows Server 2019 and Windows Server 2016.
Microsoft has made improvements to Storage Spaces Direct monitoring as well. For example, Windows Server 2019 now tracks the success or failure of every read and write drive operation, along with the operation's elapsed time. You can access this information through Windows Admin Center or a new PowerShell cmdlet.
Windows Server 2019 includes built-in outlier detection for Microsoft Storage Spaces Direct, which can help uncover abnormal drive behavior. The OS automatically collects use and performance data and stores it for up to one year, providing easy access to compute, memory, network and storage information.
Clearly, Microsoft Storage Spaces Direct in Windows Server 2019 comes with a number of important improvements. Although these additions might not be enough to convince organizations to upgrade their servers, they do provide incentive for considering such a move, especially when supporting edge systems.