vSAN improvements to RAID 5 configurations bring it to near parity with RAID 1, providing 25 percent more usable capacity. 

Many vSAN users have implemented RAID 1 configurations because the need for performance outweighed the need for efficiency. In VxRail 7.0.100, performance in erasure coding RAID 5 (“RAID 5”) configurations is greatly improved and almost entirely removes the trade-off between performance and efficiency.

vSAN 7.0 U1 enhances the read performance of RAID 5, bringing it in line with RAID 1 read performance. Improvements in the software for RAID 5 are responsible for a dramatic increase in performance between VxRail 7.0 and VxRail 7.0.100. 

This increase is consistent across RAID 5 reads and writes. However, as our tests show, write-heavy operations might still benefit from a RAID 1 (mirrored) configuration as opposed to a RAID 5 configuration. For workloads that mainly consist of random or sequential reads, the performance enhancements offered by VxRail 7.0.100 could merit upgrading VxRail environments from previous versions and migrating to a RAID 5 configuration.

Additionally, by migrating to a RAID 5 configuration to capture performance benefits, the RAID set’s usable capacity increases from 50 percent with a mirrored configuration to 75 percent with a RAID 5 configuration. In other words, using a RAID 5 configuration provides 25 percent more usable capacity. Thus, environments in need of additional storage capacity can realize both capacity and performance increases by upgrading to VxRail 7.0.100. 

You can update 36 different VxRail releases with a one-click upgrade to this latest VxRail release, going back to VxRail 4.5.211. This capability makes it easy to realize RAID 5 performance gains in most environments by simply scheduling a maintenance window to perform an upgrade. 

The benefits that VxRail 7.0.100 provides to RAID 5 are significant, making VxRail with RAID 5 a powerful option in today’s modern data centers. The benefits include up to a 30 percent increase in random read performance compared to VxRail 7.0, as highlighted in the following figure. Combining this type of performance gain with the 25 percent gain in usable capacity over a mirrored configuration makes using RAID 5 much more advisable than before. We can make this assessment even without considering the enhancements to data reduction data services (described in Conclusion #3: vSAN compression-only is nearly penalty-free).

Figure 2.              Performance gains for RAID 1, RAID 5, and RAID 6