What is important to remember about VMs when deploying Direct Attached Storage (DAS) only systems?

In a Direct Attached Storage (DAS) only deployment, storage is physically connected to a single server and is not shared. This architecture makes the physical server a self-contained failure domain. If the physical server experiences a catastrophic failure (e.g., hardware malfunction), the hypervisor (like VMware vSphere Host) and the local storage both become unavailable. Consequently, all Virtual Machines (VMs) residing on that host's local storage will inevitably go down. The failure is isolated to that specific server; VMs on other, independent physical servers with their own DAS are not impacted. This concept of an isolated failure domain is a critical consideration for DAS architectures.

B: This is factually incorrect. In a DAS-only system, a physical server failure will cause all VMs on that host to fail, as both their compute and storage resources are lost.

C: This describes the consequence of a VM's internal failure, not a characteristic of the underlying DAS storage architecture, which is the focus of the question.

D: This is incorrect. A significant failure of a VM's guest OS (e.g., kernel panic) will cause the applications and services ("components") running within that OS to cease functioning.

1. Cisco Unified Contact Center Enterprise Solution Reference Network Design (SRND)

Release 12.5(1)

Chapter: Virtualization for Unified CCE

Section: Storage. This guide explains that DAS is local to a single ESXi host. It clarifies that high-availability features like VMware HA and vMotion

which protect against server failure

require shared storage (SAN/NAS) and are not supported with DAS. This directly implies that a host failure takes down all its VMs in a DAS-only setup.

2. VMware vSphere Documentation

"vSphere Storage" for vSphere 8.0

Section: "Storage Types"

Subsection: "Direct-Attached Storage". The documentation states

"A datastore on a DAS device is accessible only to the host that the device is attached to." This confirms that the storage is not shared

making the host a single point of failure for the VMs it contains.

3. Cisco Collaboration Virtualization

Document: "Storage for Cisco Collaboration"

Section: "Storage Options". This document contrasts DAS with SAN

noting that DAS provides no storage-level redundancy between physical hosts. It reinforces that the failure of a server with DAS results in the unavailability of all VMs on that server until the server itself is restored.