VMware vSphere Virtual Volumes on Dell PS Series A technical introduction to VMware vSphere Virtual Volumes (vVols) as implemented on Dell PS Series storage Dell Engineering November 2019 A Dell Technical White Paper
Revisions Date Description March 2015 Initial release November 2019 vVols branding update THIS WHITE PAPER IS FOR INFORMATIONAL PURPOSES ONLY, AND MAY CONTAIN TYPOGRAPHICAL ERRORS AND TECHNICAL INACCURACIES. THE CONTENT IS PROVIDED AS IS, WITHOUT EXPRESS OR IMPLIED WARRANTIES OF ANY KIND. © 2015–2019 Dell Inc. All rights reserved. Dell, the DELL logo, and the DELL badge are trademarks of Dell Inc.
Table of contents Revisions ............................................................................................................................................................................................... 2 Executive summary .............................................................................................................................................................................. 4 1 Introduction to Virtual Volumes ............................................................
Executive summary The VMware® vSphere® 6.0 Virtual Volumes™ (vVols) feature is a significant change from a volume-centric approach of providing services in a virtual environment to one where SANs are VM-aware. This alters how shared storage is utilized in virtualized environments, and therefore how virtualized environments are designed. vVol SAN based services are enabled for a more granular application at a per-virtual-machine basis, and in some cases at a per-virtual-disk basis.
1 Introduction to Virtual Volumes Enabled by the second generation VMware® APIs for Storage Awareness (VASA) provider included with Virtual Storage Manager 4.5, Virtual Volumes enables storage to be virtual machine aware, and for virtual machines to be first class objects in the SAN. With Virtual Volumes, little changes in the day-to-day activities of a vSphere administrator; a virtual machine is still a virtual machine, and the workflows within VMware vCenter® do not change.
2 Virtual Volumes or Virtual Machine File System Virtual Machine File System (VMFS) and SAN volumes have been doing a satisfactory job for over a decade; why the need for change? Rather than accepting the satisfactory job that VMFS has been doing, we need to consider the limitation that VMFS has placed on the virtual environment, and the work-around or best practices that have come into play to smooth over these limitations. 2.
In previous versions of vSphere, VMware provided a datastore cluster feature. This feature groups similar datastores under one datastore cluster object. The advantage of this is that a vSphere administrator could deploy a virtual machine to the datastore cluster, and let vSphere place the virtual machine on a datastore that has sufficient capacity. However, as thin provisioned VMDKs or I/O latencies grow, virtual machines need to be migrated using vMotion® to other datastores within the cluster.
3 Why Virtual Volumes? Without vVols, cloning a virtual machine or deploying a virtual machine from a template is a large-file copy operation. While the VMware vSphere Storage APIs – Array Integration (VAAI) Full Copy primitive provides acceleration of these tasks, these operations are even faster with vVols because they become a SAN volume clone operation. A volume clone operation (the manipulation of some block pointers and reserving of space on the SAN) is completed within a matter of seconds.
- Figure 1 The Dell EqualLogic VASA Provider shipped as part of the Virtual Storage Manager plugin for vCenter, which also provides enhanced storage management functionality to vCenter. VASA Provider status as shown in vSphere Web Client • Protocol Endpoint: - - 9 The Protocol Endpoint is a unique volume on the SAN, it has a size of zero megabytes and a LUN ID of 256. It is the SAN endpoint of the communication between the ESXi™ host and the Virtual Volumes on the SAN.
Figure 2 Protocol Endpoint as shown in vSphere Web Client • Storage Container: - - - Figure 3 A Storage Container is reserved space on the SAN that can be increased and decreased as needs change, PS Series storage requires thick (or 100 percent) space reservation). It can also be conceptualized as a type of folder object on the SAN for organizing multiple volumes together. Storage Containers are seen and treated as regular datastores by vSphere, and are referred to as a vVoltype datastore.
- 3.2 See section 3.2, “Types of Virtual Volumes” for details on the different types of virtual volumes that are in a virtual machine. Types of Virtual Volumes Traditionally, a virtual machine consisted of a VMX (configuration) file, one or more VMDK files, a VSWP (memory swap) file, log files, and other miscellaneous files. With Virtual Volumes, a virtual machine consists of a collection of virtual volumes on the SAN that consume space from the Storage Container space reservation.
Figure 4 3.3 Virtual machines and virtual volumes as seen in EqualLogic Group Manager Coexisting with VMFS and migrating to Virtual Volumes Dell PS Series SANs can simultaneously provide both traditional volumes for VMFS datastores, and storage containers for virtual volume datastores. However, snapshots cannot be taken of a virtual machine that has virtual disks on both a VMFS datastore and a virtual volume datastore.
Figure 5 3.5 Storage Policy options advertised by PS Series Licensing The PS Series licensing policy is all-inclusive. As long as a customer is under a current support contract, they are entitled to features that are added to the array firmware or the host-side tools. Virtual Volumes requires Virtual Storage Manager 4.5 and PS Series firmware version 8.0, which is supported on PS Series hardware PS4000 and PS60x0 and above.
