The parent virtual disk has been modified since the child was created

[JasonKeane]

Hi All,

Having an issue after deleting some snapshots on a VEEAM Replica VM

I have studied VMware Knowledge Base on the error but Im not sure how to proceed in my situation.

Below is an extract from my VMware.log for the machine in question,

Would someone be able to give me guidance on what files I need to modify the CID on ?

Thanks in advance

Jason

2020-04-08T20:14:39.589Z| worker-2336863| I125: DISKLIB-LINK  : DiskLinkIsAttachPossible: Content ID mismatch (parentCID ee35c77a != 39ef6d49) /vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER-000004.vmdk /vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER.vmdk.

2020-04-08T20:14:39.589Z| worker-2336863| I125: DISKLIB-CHAIN : "/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER.vmdk" : failed to open (The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child).

2020-04-08T20:14:39.589Z| worker-2336863| I125: DISKLIB-VMFS  : "/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER-000004-delta.vmdk" : closed.

2020-04-08T20:14:39.589Z| worker-2336863| I125: DISKLIB-VMFS  : "/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER-flat.vmdk" : closed.

2020-04-08T20:14:39.589Z| worker-2336863| I125: DISKLIB-LIB   : Failed to open '/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER-000004.vmdk' with flags 0xa The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child (18).

2020-04-08T20:14:39.589Z| worker-2336863| I125: DISK: Cannot open disk '/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER-000004.vmdk': The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child (18).

2020-04-08T20:14:39.637Z| vmx| I125: DISKLIB-VMFS  : "/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-000008-delta.vmdk" : open successful (10) size = 1540096, hd = 31721958. Type 9

2020-04-08T20:14:39.637Z| vmx| I125: DISKLIB-DSCPTR: Opened [0]: "MYREPLICASERVER_1-000008-delta.vmdk" (0xa)

2020-04-08T20:14:39.637Z| vmx| I125: DISKLIB-LINK  : Opened '/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-000008.vmdk' (0xa): vmfsSparse, 1572864000 sectors / 750 GB.

2020-04-08T20:14:39.638Z| vmx| I125: DISKLIB-VMFS  : "/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-flat.vmdk" : open successful (14) size = 805306368000, hd = 95947240. Type 3

2020-04-08T20:14:39.638Z| vmx| I125: DISKLIB-DSCPTR: Opened [0]: "MYREPLICASERVER_1-flat.vmdk" (0xe)

2020-04-08T20:14:39.638Z| vmx| I125: DISKLIB-LINK  : Opened '/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1.vmdk' (0xe): vmfs, 1572864000 sectors / 750 GB.

2020-04-08T20:14:39.638Z| vmx| I125: DISKLIB-LINK  : DiskLinkIsAttachPossible: Content ID mismatch (parentCID a741bab8 != 865b5382) /vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-000008.vmdk /vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1.vmdk.

2020-04-08T20:14:39.638Z| vmx| I125: DISKLIB-CHAIN : "/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1.vmdk" : failed to open (The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child).

2020-04-08T20:14:39.638Z| vmx| I125: DISKLIB-VMFS  : "/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-000008-delta.vmdk" : closed.

2020-04-08T20:14:39.638Z| vmx| I125: DISKLIB-VMFS  : "/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-flat.vmdk" : closed.

2020-04-08T20:14:39.638Z| vmx| I125: DISKLIB-LIB   : Failed to open '/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-000008.vmdk' with flags 0xa The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child (18).

2020-04-08T20:14:39.638Z| vmx| I125: DISK: Cannot open disk '/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-000008.vmdk': The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child (18).

2020-04-08T20:14:39.638Z| vmx| I125: Msg_Post: Error

2020-04-08T20:14:39.638Z| vmx| I125: [msg.disklib.CID_MISMATCH] The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child

2020-04-08T20:14:39.638Z| vmx| I125: [msg.disk.noBackEnd] Cannot open the disk '/vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER_1-000008.vmdk' or one of the snapshot disks it depends on.

2020-04-08T20:14:39.638Z| vmx| I125: ----------------------------------------

2020-04-08T20:14:39.639Z| vmx| I125: DISK: Opening disks took 57 ms.

2020-04-08T20:14:39.639Z| vmx| I125: Module 'Disk' power on failed.

2020-04-08T20:14:39.639Z| vmx| I125: VMX_PowerOn: ModuleTable_PowerOn = 0

2020-04-08T20:14:39.639Z| vmx| I125: SVMotion_PowerOff: Not running Storage vMotion. Nothing to do

2020-04-08T20:14:39.640Z| vmx| I125: Vix: [mainDispatch.c:1180]: VMAutomationPowerOff: Powering off.

2020-04-08T20:14:39.640Z| vmx| W115: /vmfs/volumes/57bc84bd-3b662b92-5b3f-000af7960f6c/MYREPLICASERVER_replica/MYREPLICASERVER.vmx: Cannot remove symlink /var/run/vmware/0/1304039500522_2336855/configFile: No such file or directory

2020-04-08T20:14:39.640Z| vmx| I125: WORKER: asyncOps=2 maxActiveOps=2 maxPending=1 maxCompleted=0

2020-04-08T20:14:39.648Z| vmx| I125: Vix: [mainDispatch.c:4239]: VMAutomation_ReportPowerOpFinished: statevar=1, newAppState=1873, success=1 additionalError=0

2020-04-08T20:14:39.648Z| vmx| I125:

[tayfundeger]

When you search for CID in vmware.log files, you will see which CID you need to change. If you have not done this before, you should get professional support.

[daphnissov]

Having an issue after deleting some snapshots on a VEEAM Replica VM

And, generally speaking, you shouldn't be manually deleting those snapshots that Veeam creates, because those are the restore point for the replica. Now that you've deleted them, you've probably created a synchronization issue between the state of the VM and what Veeam knows about.

[JasonKeane]

daphnissov / Tayfun

Thanks for your very quick response,

I was advised by Veeam to remove all snapshots as we were getting errors during replication.

All other VM's have worked with the exception of this one which is coming up with the aforementioned error.

This query is in relation to a _replica VM so as such I'm prepared to risk messing it up if someone would give me guidance .

Bottom line is, I can start a new replication job from scratch but its going to take an age due to bandwidth limitations so If anyone could /would point me in the right direction id be very grateful. If it doesnt work then I'm going to be forced to replicate from scratch anyway so nothing to lose by trying it if someone is prepared to give me guidance ?

If you need more logs etc, I can provide no issue

[tayfundeger]

You can't power virtual machine right now, right? Can you show how many snapshots are there? Also can you send the virtual machine's edit settings> partition?

[continuum]

Hi

connect to the host with WinSCP.

Go to the directory where the VM is stored and copy all small vmdk-files that do not have "flat", "delta" or "sesparse" in the name to your admin host.zip them all together and attach them to your next reply.

We will also need a copy of the vmx-file.

[JasonKeane]

Hi Tayfun,

Continuum appears to be working on this also so I don't want to waste anyone's time but

the info you are looking for is attached and correct the machine will not power on.

Thanks for your help

[JasonKeane]

Hi Continuum

Appoligies, I don't see the attachment II sent..

[continuum]

If I set the CIDs according to the the chain information inside the vmdk descriptorfiles some of the snapshots will be bypassed.

You can do that - but are you sure about it ?
That would result in one delta per vmdk and would skip some of the deltas.
Please send all vmware.logs that you have inside the directory and show the timestamps of the vmdk--files so that I can check if there are really stale snapshots involved here.

[JasonKeane]

Hi Continuum

I'm not sure what a missing delta would mean to me ?

My aim is to get as recent a base disk as possible so I can use it as a seed for Veeam replication.

[continuum]

Is going back to the state of 2020-04-08T20:14:39.435 ok ?

[JasonKeane]

Thats great Continuum, Thanks for your help on this

[JasonKeane]

Yes, that date will be fine,

[continuum · Accepted solution]

Replace the 2 vmdks with edited ones and leave everything else as is.

[JasonKeane]

That looks to have resolved my issue,

Now to see does Veeam pick up where it needs to.

Thanks a million for all your help on this Continuum, really appreciate it.

[TarunRana1]

Hello Everyone, I have the same issue while doing  disk consolidation i am get "An error occurred while consolidating disks: The parent virtual disk has been modified since the child was created. The content ID of the parent virtual disk does not match the corresponding parent content ID in the child"

1. VM is unable to power ON.

2.Disk size in 0 MB in edit settings.

Please help.Thanks in advance

[TarunRana1]

Solution on my below issue.

modify VM hard disk to point a parent virtual disk file by doing the following steps:

1. Locate a parent virtual disk file (Browse datastore and VM folder)
2. Remove a Virtual Disk from a Virtual Machine. In my case I need to remove (without deleting from disk) 
3. Add / Map an Existing Virtual Disk to a Virtual Machine.
4. After browsing and adding disk, click OK to save changes.
5. If you receive the following warning you need to consolidate files (snapshots):To consolidate the files, right-click the virtual machine and select Snapshot > Consolidate.
6. Power on VM.
7. its working for me 🙂