Today vCenter Server 6.0U3c is released. As per me, though this release is a patch release but looks like lot of improvements done on various vCenter/ESXi components. I had an opportunity to work on some of Storage DRS (aka SDRS) issues and I thought to share those with you. In fact, there are multiple improvements done from Storage DRS perspective but I am sharing some of very interesting ones. Below is the content from release notes with respect to Storage DRS.
1. Storage DRS might place the thin provisioned disks into one datastore, instead of distributing them evenly
During the initial placement of thin provisioned disks, the Storage Distributed Resource Scheduler (SDRS) might miscalculate the entitled space requirement by excluding the reserved space. As a result, SDRS might use only the committed megabytes for the entitled space calculation, causing a wrong placement recommendation on one datastore, instead of distributing them evenly. This issue is resolved in this release.
2. Storage DRS generates only one suitable datastore for initial virtual machine placement
In case there are virtual machines with Raw Device Mapping (RDM) virtual disks, the Storage DRS might consider the actual mapping file size instead of the pointer file size, even though it does not consume any disk space. As a result, the Storage DRS might generate only one suitable datastore when creating new virtual machines. This issue is resolved in this release.
3.vCenter Server might fail in attempt to create a virtual machine on a Storage DRS cluster using script with null CPU or Mem Share values
vCenter Server might fail if you attempt to create a virtual machine on a Storage DRS cluster using a script with null CPU or Mem Share values in a RecommendDatastores() API call. This issue is resolved in this release.
Based on above info, you might have got the high level insights on these SDRS improvements. If you ask me, all are really good improvements from SDRS perspective. In my future blog posts, I will have deep dive into each of the above issues.
I think, if you are using SDRS, it is one of the great reasons to upgrade your environment (apart from important fixes on other vCenter/ESXi areas)
Important links
Download vCenter Server 6.0U3c bits here
vCenter server 6.0 U3c release notes
Yes, there is corresponding ESXi release, please take a look at this KB
It seems, there are some great improvements made to VMware vSAN as well, please take a look at this KB
Vikas Shitole is a Senior Tech Lead at VMware by Broadcom, VCF division, India, where he leads system test efforts—including scale, stress, and resiliency testing—and drives product quality across VMware Cloud Foundation (VCF), Broadcom’s flagship private cloud platform.
He is an AI and Kubernetes enthusiast, and is passionate about VMware customers and automation around vSphere and VCF. Vikas has been honored as a vExpert for 12 consecutive years (2014–2025) for his sustained technical contributions and community leadership.
He is the author of two VMware Flings, holds multiple industry certifications, and is one of the top contributors to the VMware API Sample Exchange, where his automation scripts have been downloaded over 50,000 times.
Vikas has shared his expertise as a speaker at international conferences such as VMworld Europe and VMworld USA, and was selected as an official VMworld 2018 blogger. He also served as lead technical reviewer for the Packt-published books vSphere Design and VMware Virtual SAN Essentials.
Beyond tech, Vikas is a dedicated cricketer, cycling enthusiast, and a lifelong learner in fitness and nutrition, with the personal goal of completing an Ironman 70.3