Pure Storage CEO Scott Dietzen wrote in a Wednesday blog post that it's no accident XtremIO and Pure Storage look very similar. All-flash storage, Dietzen wrote, needs high availability with dual-parity or better RAID protection, the ability to do no-disruptive upgrades, in-line deduplication, and no-overhead snapshots and clones. "Pure and XtremIO are the only all-flash arrays offering this feature set today, and I submit that our mutual competitors are still a long way from delivering the above recipe. ... The last place you want to be as an early-stage company is looking up at EMC because you are behind on critical features, but that is arguably where the rest of the all-flash field wakes up tomorrow, with Pure Storage the notable exception." Dietzen said that, while it may seem odd to give EMC so much credit, Pure Storage offers several advantages stemming from running production workloads for three years, including a hardened architecture, persistent metadata, lossless deduplication, scale-up and scale-out design (vs. the scale-out design of XtremIO), and variable block sizes.