Storage DRS Fails to Perform Storage vMotion Due to Mounted ISO or SDRS Disabled on VM

Products

• VMware vCenter Server

Issue/Introduction

_{Storage DRS (SDRS) fails to automatically migrate virtual machines between datastores, even when the SDRS migration threshold is met.}

_{Example Scenarios:}

• _{SDRS is configured in automatic mode but no Storage vMotion is initiated.}
• _{Manual Storage vMotion succeeds for the same VM.}
• _{SDRS logs indicate that migration was skipped.} 

_{Log snippets of /var/log/vmware/vpxd}

info vpxd[#####] [Originator@#### sub=sdrsLogger opID=#####] SDRS disabled for vm <vmname> disk #####, reason 15 

info vpxd[#####] [Originator@#### sub=sdrsLogger opID=#####] DrmFault: reason balanceDatastoreSpaceUsage, vm NotFoundObject, host NotFoundObject, fault [StorageDrsCannotMoveVmWithMountedCDROME]

• ^{These entries indicate SDRS is bypassing certain VMs due to SDRS is disabled}
• ^{Also due to mounted ISO devices}

Environment

^{VMware vCenter Server 7.x}

^{VMware vCenter Server 8.x}

Cause

^{This issue typically occurs due to one or more of the following reasons:}

1. ^{SDRS is disabled at the VM level, preventing automated migration.}
2. ^{VMs have ISO files mounted from datastores that are not part of the datastore cluster, causing SDRS to skip those VMs.}
3. ^{Mounted CD/DVD drives referencing non-cluster datastores restrict SDRS operations.}

Resolution

^{To restore normal SDRS functionality and allow automatic Storage vMotion, perform the following steps:}

^{Step 1: Ensure SDRS is Enabled for All VMs}

• ^{In the vSphere UI, navigate to storage DRS cluster}
• ^{Configure → VM overrides and Check that Storage DRS automation level is not set to manual or disabled.}

^{Step 2: Unmount ISO Files}

• ^{Edit each VM and locate the CD/DVD drive settings.}
• ^{Set the device to Client Device.}
• ^{Ensure no ISOs are mounted from datastores outside the cluster.}

^{Step 3: Confirm Datastore Cluster Membership}

• ^{Verify that all datastores involved in VM operations are included in the same datastore cluster where SDRS is configured.}