vSAN 7.0 U1 provides up to 7x faster drive rebuild times, which:

• Reduces risk and exposure during drive failure
• Decreases the time required to get back to full performance
• Allows users to take advantage of increasing drive sizes

The improved performance of VxRail 7.0 U1 tips the scales for users, providing more options when balancing the trade-offs between cost, efficiency, and requirements.

As previously mentioned, regardless of the platform and service, there is always a trade-off between the benefit that a data service provides and the impact that it has. 

In vSAN 7.0 U1, compression is available as a data reduction method on its own, apart from the deduplication and compression data service. With compression-only enabled, the trade-off for data reduction has been reduced. As discussed in Conclusion #3: vSAN compression-only is nearly penalty-free, we saw that the performance impact was significantly reduced. Under compression-only, the failure of a capacity drive only affects that device and does not take the entire disk group offline as it does with deduplication and compression. This smaller failure domain shrinks the impact of a disk failure and reduces the potential amount of data that vSAN needs to rebuild when a disk failure occurs.

The following figure shows that vSAN 7.0 U1 provides important gains in drive rebuild transfer rates. It also shows that enabling deduplication and compression has a significant impact—up to more than 7x—on drive rebuild transfer rates. However, the impact on drive rebuild transfer rates is significantly reduced when compression-only is enabled. This faster transfer rate, coupled with the reduced failure domain and reduced performance impact, makes compression-only a viable option for even the most demanding compression-friendly workloads. Such workloads include mixed workloads with large I/O block sizes, RDBMS and OLTP databases, and VDI workloads using linked clones.

Figure 4.              Improvements in drive rebuild transfer rates