Unable to power on the VM when I/O filters are enabled.
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Unable to power on the VM when I/O filters are enabled.

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Article ID: 334555

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

  • Virtual machine power-on operation may fail.

Error File system specific implementation of OpenFile[file] failed
Failed to start the virtual machine.
Module Disk power on failed.
Cannot open the disk '/vmfs/volumes/vsan:datastore/vm-folder/VM-Name_2.vmdk' or one of the snapshot disks it depends on.

  • Also, you may see snapshot consolidation fails with the following error:

Error Message: Generic error: Cannot open the disk '/vmfs/volumes/XXXXXXXX-XXXX-XXXX-XXXXXXXXXXXX/VMNAME-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX/VMNAME-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX-000001.vmdk' or one of the snapshot disks it depends on.

Environment

  • VMware vSphere ESXi 7.x
  • VMware vSphere ESXi 8.x
  • VMware vSphere ESXi 9.x

Cause

  • The issue is see when there is an iofilter attached to the VMDK. The iofilter would have attached for backup, dataprotection or replication purpose as part of data protection.

  • You can validate this by editing the VMDK which is causing the VM power on failure. Upon verifying the VMDK, you may see the ddb.sidecars and iofilter enabled.

[root@host:/vmfs/volumes/vsan:Datastore/VM-Folder] cat VM_2.vmdk
# Disk DescriptorFile
version=5
encoding="UTF-8"
CID=20d3477a
parentCID=ffffffff
createType="vmfs"

# Extent description
RW 419430400 VMFS "vsan://Datastore/17970d68-2ae6-99e6-5ba9-########"

# The Disk Data Base
#DDB

ddb.adapterType = "lsilogic"
ddb.geometry.cylinders = "26108"
ddb.geometry.heads = "255"
ddb.geometry.sectors = "63"
ddb.iofilters = "spif:vmwarelwd"
ddb.longContentID = "aacf0f1bb564b9f847a84d2920d3477a"
ddb.sidecars = "vmwarelwd_2,########_2-7438a62874a1489e.vmfd;vmwarelwd_1,########_2-6991bfaeaec74182.vmfd"
ddb.thinProvisioned = "1"
ddb.toolsInstallType = "4"
ddb.toolsVersion = "12416"
ddb.uuid = "60 00 C2 91 5b 44 8d 44-74 66 1f e9 2e 93 7d 75"
ddb.virtualHWVersion = "14"
[root@host:]

  • We see from vmware.log for the virtual machine show the below deadlock events for sidecar.

vmware.log

2026-01-16T02:34:11.442Z In(05) vmx f85a3d9d FILE:open error on /vmfs/volumes/vsan:52413b9d3b0bf051-########/3f8c0d68-8850-b864-0972-########/########_2-6991bfaeaec74182.vmfd: Resource deadlock avoided
2026-01-16T02:34:11.442Z In(05) vmx f85a3d9d OBJLIB-FILEBE : FileBEOpen: can't open '/vmfs/volumes/vsan:52413b9d3b0bf051-########/3f8c0d68-8850-b864-0972-########/########_2-6991bfaeaec74182.vmfd' : Resource deadlock avoided (2293764).
2026-01-16T02:34:11.442Z In(05) vmx f85a3d9d SidecarOpenInt: Failed to open sidecar file '/vmfs/volumes/vsan:52413b9d3b0bf051-########/3f8c0d68-8850-b864-0972-########/########_2-6991bfaeaec74182.vmfd' with flags 4013, Resource deadlock avoided (230004).
2026-01-16T02:34:11.442Z In(05) vmx f85a3d9d DISKLIB-LIB_SIDECAR : DiskLibSidecarOpenInt: Failed to open side car for filter 'vmwarelwd_1': Resource deadlock avoided.
2026-01-16T02:34:11.442Z In(05) vmx f85a3d9d FiltLib: vmwarelwd: Opening sidecar failed: "Resource deadlock avoided" (2293769).

Resolution

In order to resolve the issue, please validate if the VM is enabled with any data protection or VM is being replicated. If the VM is not replicated or not protected with any data protection services, you can edit the affected VMDK and hash out the lines below.

NOTICE: Removal of the vmwarelwd filter from a VM that is being protected requires re-enabling it on the VM at a later point. The execution of the attached script should be performed only against VMs that are no longer to be protected by VCDR or other solutions that leverage the vmwarelwd filter.

Steps to workaround:

  • Make a copy of vmdk descriptior.

  • Hash out the following parameters: ddb.sidecars and ddb.iofilter from the descriptor and the snapshot descriptor files for the affected vmdk.

# Disk DescriptorFile
version=5
encoding="UTF-8"
CID=20d3477a
parentCID=ffffffff
createType="vmfs"
# Extent description
RW 419430400 VMFS "vsan://52413b9d3b0bf051-#####/17970d68-2ae6-99e6-5ba9-####"
# The Disk Data Base
#DDB
ddb.adapterType = "lsilogic"
ddb.geometry.cylinders = "26108"
ddb.geometry.heads = "255"
ddb.geometry.sectors = "63"
#ddb.iofilters = "spif:vmwarelwd"
ddb.longContentID = "aacf0f1bb564b9f847a84d2920d3477a"
#ddb.sidecars = "vmwarelwd_2,####-7438a62874a1489e.vmfd;vmwarelwd_1,####-6991bfaeaec74182.vmfd"
ddb.thinProvisioned = "1"
ddb.toolsInstallType = "4"

  • Another Sample VMDK:

    # Disk DescriptorFile
    version=5
    encoding="UTF-8"
    CID=3018dd88
    parentCID=ffffffff
    isNativeSnapshot="no"
    createType="vmfs"

    # Extent description
    RW 209715200 VMFS "VMNAME-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX-flat.vmdk"

    # Change Tracking File
    changeTrackPath="VMNAME-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX-ctk.vmdk"

    # The Disk Data Base
    #DDB

    ddb.adapterType = "lsilogic"
    ddb.deletable = "true"
    ddb.encoding = "UTF-8"
    ddb.geometry.biosCylinders = "13054"
    ddb.geometry.biosHeads = "255"
    ddb.geometry.biosSectors = "63"
    ddb.geometry.cylinders = "13054"
    ddb.geometry.heads = "255"
    ddb.geometry.sectors = "63"
    #ddb.iofilters = "iofilter-provider"
    ddb.longContentID = "96799446337cbb3c59a5c7ab3018dd88"
    #ddb.sidecars = "iofilter-provider_1,VMNAME-########-####-####-####-############-################.vmfd"
    ddb.toolsInstallType = "2"
    ddb.toolsVersion = "10282"
    ddb.uuid = "## ## ## ##"
    ddb.virtualHWVersion = "11"

Disabling the iofilters is expected to power on the VM. However, if there was any data protection configured for the VM and if it was using iofilter, you may have to re-enable.

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