Help attaching unattached differencing image

[mrpetkus]

Folks,
I'm stuck and need assistance.
Background:
Had an issue last Friday where a VM wouldn't load - as I debugged the problem I encountered various messages such as:
"differencing image not associated with parent"
"differencing but not associated with any parent in media registry"
"Parent medium with UUID x not found in media registry"

I was able to salvage the VM by deleting and recreating the guest and re-writing the UUIDs.

Problem:
Although the system is online, I can't attach the last good snapshot - it's a differencing image but it's not listed on the tree.
How do I attach it to the parent?

Relevant info from Virtualbox.xml:
<HardDisk uuid="{2842ed95-6239-4bfe-8276-a24e46707f36}" location="/VIRTUAL2/VALUABLE.vdi" format="VDI" type="Normal">
<HardDisk uuid="{3466a3a4-818a-4e1d-a716-26d48b27a1c9}" location="/VIRTUAL2/Snapshots/{3466a3a4-818a-4e1d-a716-26d48b27a1c9}.vdi" format="VDI"/>
<HardDisk uuid="{ebf6320b-1c76-48dc-befc-ad4a14766ea7}" location="/root/.VirtualBox/Machines/IRMIS-DEV/Snapshots/{ebf6320b-1c76-48dc-befc-ad4a14766ea7}.vdi" format="VDI">
<HardDisk uuid="{d604b91e-a5a4-45f7-9900-3d597193b4d6}" location="/VIRTUAL2/Snapshots/{d604b91e-a5a4-45f7-9900-3d597193b4d6}.vdi" format="VDI"/>

{ebf6320b-1c76-48dc-befc-ad4a14766ea7}.vdi is the differencing image that is unattached

Output of dumphdinfo on Parent:
VM-SERVER:/VIRTUAL2# VBoxManage internalcommands dumphdinfo VALUABLE.vdi
Oracle VM VirtualBox Command Line Management Interface Version 3.2.8
(C) 2005-2010 Oracle Corporation
All rights reserved.

--- Dumping VD Disk, Images=1
Dumping VD image "VALUABLE.vdi" (Backend=VDI)
Dumping VDI image "VALUABLE.vdi" mode=r/w uOpenFlags=8 File=0x000000006e47a0
Header: Version=00010001 Type=1 Flags=0 Size=107374182400
Header: cbBlock=1048576 cbBlockExtra=0 cBlocks=102400 cBlocksAllocated=34347
Header: offBlocks=512 offData=410112
Header: Geometry: C/H/S=1024/255/63 cbSector=512
Header: uuidCreation={2842ed95-6239-4bfe-8276-a24e46707f36}
Header: uuidModification={bb999958-cdf0-47a0-9e2f-70b3089029aa}
Header: uuidParent={00000000-0000-0000-0000-000000000000}
Header: uuidParentModification={00000000-0000-0000-0000-000000000000}
Image: fFlags=00000000 offStartBlocks=512 offStartData=410112
Image: uBlockMask=000FFFFF cbTotalBlockData=1048576 uShiftOffset2Index=20 offStartBlockData=0

Output of dumphdinfo on Child differencing image that is not attached that I want to attach:
controlarchiver:/VIRTUAL2/Snapshots# VBoxManage internalcommands dumphdinfo \{3466a3a4-818a-4e1d-a716-26d48b27a1c9\}.vdi
Oracle VM VirtualBox Command Line Management Interface Version 3.2.8
(C) 2005-2010 Oracle Corporation
All rights reserved.

--- Dumping VD Disk, Images=1
Dumping VD image "{3466a3a4-818a-4e1d-a716-26d48b27a1c9}.vdi" (Backend=VDI)
Dumping VDI image "{3466a3a4-818a-4e1d-a716-26d48b27a1c9}.vdi" mode=r/w uOpenFlags=8 File=0x000000006e6130
Header: Version=00010001 Type=4 Flags=0 Size=107374182400
Header: cbBlock=1048576 cbBlockExtra=0 cBlocks=102400 cBlocksAllocated=11673
Header: offBlocks=512 offData=410112
Header: Geometry: C/H/S=1024/255/63 cbSector=512
Header: uuidCreation={3466a3a4-818a-4e1d-a716-26d48b27a1c9}
Header: uuidModification={a4d419d2-dd30-409d-8307-1e455df98f52}
Header: uuidParent={2842ed95-6239-4bfe-8276-a24e46707f36}
Header: uuidParentModification={bb999958-cdf0-47a0-9e2f-70b3089029aa}
Image: fFlags=00020000 offStartBlocks=512 offStartData=410112
Image: uBlockMask=000FFFFF cbTotalBlockData=1048576 uShiftOffset2Index=20 offStartBlockData=0

[mrpetkus]

While waiting for all the replies to roll in, I decided to play around some more.

I'm able to reattach the differencing image by:
-Turning off the VM
-Selecting the differencing image as the Primary Master in storage
-Viola!

My question now is,
When looking in Virtual Media Manager, I can see the differencing image is now attached *but* the parent image (Normal (VDI)) is Not Attached.
Why is this? Other VMs on this same host have the normal parent attached. Is there a way to fix this?

Thanks in advance.

[MarkCranness]

Had an issue last Friday where a VM wouldn't load - as I debugged the problem I encountered various messages such as:
"differencing image not associated with parent"
"differencing but not associated with any parent in media registry"
"Parent medium with UUID x not found in media registry"

BACKUP, then probably apply this fix to your base VDI file (ONLY):
http://forums.virtualbox.org/viewtopic. ... 60#p150464

My question now is,
When looking in Virtual Media Manager, I can see the differencing image is now attached *but* the parent image (Normal (VDI)) is Not Attached.
Why is this? Other VMs on this same host have the normal parent attached. Is there a way to fix this?

Not without manually editing the machine xml and VirtualBox.xml files.

If you don't need to ever Restore back to the first snapshot that you used to have, then create a clonehd of the Current State (instructions here: http://forums.virtualbox.org/viewtopic.php?p=149887), then release and unattach the existing files and use the clone instead.

If you WILL at some point need to restore to that original snapshot, ask here.