parent UUID of the medium does not match

Allgemeine Diskussionen über den Einsatz von VirtualBox.
fth0
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Re: parent UUID of the medium does not match

Post by fth0 »

Eine VM ist das Gegenstück zu einem physikalischen Computer, und eine VDI-Datei ist das Gegenstück zu einer physikalischen Festplatte. Und jetzt lies bitte noch einmal was mpack und Du zuletzt geschrieben haben ...

A VM is the equivalent of a physical computer, and a VDI file is the equivalent of a physical hard disk. Please re-read what mpack and you have written lately ...
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Re: parent UUID of the medium does not match

Post by VM-F4n »

@fth0
Mir ist schon klar, was mpack geschrieben hat :wink: , nämlich dass die .vdi einer VM hinzugefügt werden soll - brauch ich aber doch nicht (mehr).
Sie läuft eigenständig und nur wenn ich darauf was benötige schalte ich die VM noch mal an.
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Re: parent UUID of the medium does not match

Post by Martin »

Nein, er hat nur Deine fehlerhafte Formulierung "Ich nutze die VM, die CloneVDI erzeugt hat..." korrigiert.
CloneVDI erzeugt keine VMs, nur VDIs/Festplatten. ;)

Auch wenn Du das bestimmt implizit so gemeint hast, könnte es halt jemand beim späteren Lesen dann falsch interpretieren.
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Re: parent UUID of the medium does not match

Post by fth0 »

VM-F4n wrote:Sie läuft eigenständig
Wenn sich das "Sie" auf eine VDI-Datei bezieht, dann ist diese Aussage entweder falsch, unvollständig oder verwendet das falsche Vokabular. Und wir wollen etwaige Mitleser ja nicht unnötig verwirren. ;)
MarkFalk
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Re: parent UUID of the medium does not match

Post by MarkFalk »

VM-F4n wrote: Edit:
Für alle die es evtl. irgenwann mal benötigen können... der richtige Befehl:

Code: Select all

VBoxManage internalcommands sethdparentuuid "complete-path-to-{594b0bd7-6302-4b7d-ae0d-46ebb2b5e916}.vdi" "{847217ee-b549-4ae5-b0ef-ba9491afbe28}"
Ich denke, man sollte für alle, die sich nicht lange einlesen und das im einzelnen verstehen können oder wollen (bei den ersten zwei, drei Durchsichten des verlinkten Beitrags viewtopic.php?f=6&t=79896 hatte ich nur "Bahnhof" verstanden), klarstellen, daß die von Dir genannten UUID natürlich nur in Deinem Fall richtig sind.

Die allgemeine Anweisung lautet wie ich sie mit

vboxmanage internalcommands sethdparentuuid "(path to corrupted snapshot-file)" {(UUID of parent)}

zitiert habe, wobei gilt:

"(path to corrupted snapshot-file)" steht für den kompletten Pfad einschließlich Dateibezeichnung der als fehlerhaft (ohne gültige parent-UUID) gemeldeten snapshot-Datei. Wenn man vboxmanage.exe aus dem Verzeichnis der betreffenden snapshot-Datei heraus ausführt (dann aber mit der gesamten Pfadangabe zu vboxmanage.exe) muß man natürlich nicht den gesamten Pfad eingeben sondern nur die Dateibezeichnung. Ich empfinde es als einfacher, die Eingabeaufforderung im VirtulBox-Programmverzeichnis zu öffnen und den vollständigen Pfad nebst Dateibezeichnung aus dem Massenspeicher-Eintrag in den Einstellungen der betreffenden VM zu kopieren - aber das kann jeder machen wie er lustig ist. Die "" sind nur bei Leerzeichen in Pfad oder Dateibezeichnung erforderlich, schaden m.E. aber nicht. Zwischen der Dateibezeichnung bzw. dem abschließenden " und der folgenden parent-UUID (d.h. der dies einleitenden geschweiften Klammer "{") muß ein Leerzeichen stehen.

"(UUID of parent)" steht für die vermißte UUID der parent-Datei (einzugeben mit/in den geschweiften Klammern). Bei dieser Datei handelte es sich bei mir (in meinen Problemfällen) um die originäre/originale VM-Datei, aber ich vermute, daß es sich bei Fehlern in einer Kette von snapshot-Dateien auch um eine parent-snapshot-Datei handeln kann/könnte. In meinem Fall bzw. in meinen Problemfällen mußte ich diese parent UUID nicht "umständlich", wie in dem verlinkten Beitrag viewtopic.php?f=6&t=79896 erläutert, aus der betreffenden parent-Datei mittels vboxmanage.exe herausholen sondern konnte einfach die in der eigentlichen Fehlermeldung als fehlende beanstandete und genannte parent-UUID mittels c&p übernehmen und einfügen.

Ich bitte um Nachsicht, daß ich als Newbie und fast-immer-noch-VB-DAU mich hier etwas oberlehrerhaft einlasse, abergerade weil ich noch völlig am Anfang stehe kann ich mich gut in die Situation eines noch blutigeren Anfängers, soweit das möglich ist, hineindenken - sie steht mir sozusagen täglich vor Augen ;-).
MarkFalk
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Re: parent UUID of the medium does not match

Post by MarkFalk »

mpack wrote:
MarkFalk wrote:
scottgus1 wrote:CloneVDI also never changes the original files
Are you sure?
Very sure.
Sorry, but your quote is incorrect. Your wrote

"CloneVDI also never changes the original files, whereas Virtualbox does change the originals."

With my request "Are you sure?" I referred to your last statement "whereas Virtualbox does change the originals". And this is not correct. I have tested it several times and VB also does not touch the original VM-files.
In fact the "freeware.de" tool called CloneVDI existed before my tool, but I was unaware of it at the time because it was only discussed on German speaking forums, and online translation did not exist at the time. ...
Thanks for this explanation.
The "freeware.de" tool is not equivalent to my CloneVDI, it is only a GUI wrapper around VBoxManage and hence can provide no feature unless VBoxManage provides it first. If VBoxManage fails on a particular VDI then the freeware.de GUI will also fail. Since modern VirtualBox has it's own GUI now I would assume that the "freeware.de" tool is defunct.
Of course as "only" a GUI for VBoxManage.exe this software can not work better or in an other way or give more functionality than VBoxManage.exe. But I am to new and ignorant in this VB-matter to judge whether the tool has still some sense and useful functionality.
But it clones .VDI only - means: It accepts as input also .vhd, but it generates .vdi only, doesn´t matter the given extension.
Absolutely. CloneVDI will only ever output the VirtualBox native format: I don't believe in adding placebo features. CLoneVDI is specifically intended to be a VirtualBox support tool - I have no interest in supporting other VM platforms.
So the "old" GUI for VBoxManage still has a senseful functionality - simple cloning .vhd-files.
On the other hand - when a files get damaged it doesn´t matter if it is one single VM-file or one of a dozend files of a VM.
It matters a great deal. A single file (i.e. with no dependencies) is much easier to backup, restore - and most importantly - to repair.
IMHO the only real disadvantage is the chaining itself, when the chaining is not reliable - as in all the cases we see in this discussion. Obviously nobody can explain why the snapshoot-file can "forget" the parent-UUIDs w/o any irregluar event. This should be absolutely impossible.
scottgus1
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Re: parent UUID of the medium does not match

Post by scottgus1 »

MarkFalk wrote:Sorry, but your quote is incorrect.
Actually, I wrote:
scottgus1 wrote:whereas Virtualbox does change the originals."
I may be wrong on whether vboxmanage changes the originals. It has been a long time since I tried it, and the devs may have changed the command's behavior. I am fairly certain, it used to change the original. In fact, since the actual 'vboxmanage modifymedium' command does not apparently contain an option to pick an output file name, I'd be pretty sure it still does change the original file. And for what it's worth I just tried 'vboxmanage modifymedium drive:\path\to\a\vdi --compact' and the Date Last Modifed updated, so I still do believe that 'vboxmanage modifymedium' does change the original file.

I am sure that Mpack's CloneVDI does not change the originals, as Mpack would be even more sure since he wrote it. :lol:
MarkFalk wrote:nobody can explain why the snapshoot-file can "forget" the parent-UUIDs w/o any irregluar event. This should be absolutely impossible.
I think it is impossible, as far as a computer can let it be impossible. Barring someone intentionally editing the disk's stored UUIDs or running a vboxmanage command to do so, or a Virtualbox bug, I think those UUIDs should never change, unless a snapshot is officially deleted in Virtualbox.

I'm sure I wrote the following in one of these recent topics on a snapshot UUID chain failing: Virtualbox re-writes the main Virtualbox.xml and the VM's .vbox file at various times during the operation of Virtualbox and the VMs. If a glitch or bug shows itself during these re-writes, this kind of error might happen.

The next time it happens, before you try to fix anything, please start a new topic. Post the error message and a zip containing Virtualbox.xml, Virtualbox.xml-prev, and the VM's .vbox and .vbox-prev files (that's 4 files in the zip). Also run 'vboxmanage showmediuminfo' on the VM's base disk and all the VM's snapshot disks. We might be able to piece together what happened.
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Re: parent UUID of the medium does not match

Post by mpack »

MarkFalk wrote: Sorry, but your quote is incorrect.
Sorry, but so is yours. The important part in the description of CloneVDI is NEVER. That means that none of the functions performed by CloneVDI ever involve modifying the original VDIs.

The logical converse of this is not that ALL of the functions of VBoxManage will alter the source VDIs. The correct logical converse is "will sometimes".

In particular, resizing or compacting a VDI using VBoxManage will change the originals.

Also, when CloneVDI was original developed, cloning was not offered by the VirtualBox UI. Snapshots were suggested instead as the appropriate means of creating multiple states of a VM. This too made changes which in practice were hard to undo safely.
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Re: parent UUID of the medium does not match

Post by mpack »

I am very aware that this secondary discussion about CloneVDI is hijacking someone else's topic. If you wish to continue this separate discussion then please start your own topic.
MarkFalk
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Re: parent UUID of the medium does not match

Post by MarkFalk »

scottgus1 wrote:
MarkFalk wrote:Sorry, but your quote is incorrect.
Actually, I wrote:
scottgus1 wrote:whereas Virtualbox does change the originals."
I may be wrong on whether vboxmanage changes the originals. It has been a long time since I tried it, and the devs may have changed the command's behavior. I am fairly certain, it used to change the original.....
Maybe there is a misunderstanding. In my understanding we talked about clonig only. And in reg. of cloning I am sure- due to my several tests - that VB does not touch the original file. But I agree that we should stop talking about this and CloneVDI in this discussion.
I'm sure I wrote the following in one of these recent topics on a snapshot UUID chain failing: Virtualbox re-writes the main Virtualbox.xml and the VM's .vbox file at various times during the operation of Virtualbox and the VMs. If a glitch or bug shows itself during these re-writes, this kind of error might happen.
This is my assumption: A bug in VB. In my reported cases no irregular event in the PC or it´s operation or the harddisks occured and I also did not change anything in the VMs. So the only expalantion for the event of the "lost" parent-UUID I can imagine is a bug.
The next time it happens, before you try to fix anything, please start a new topic. Post the error message and a zip containing Virtualbox.xml, Virtualbox.xml-prev, and the VM's .vbox and .vbox-prev files (that's 4 files in the zip). Also run 'vboxmanage showmediuminfo' on the VM's base disk and all the VM's snapshot disks. We might be able to piece together what happened.
I will keep in mind.
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