[Solved] Cyclic redondancy check

Discussions related to using VirtualBox on Windows hosts.
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Leloup78
Posts: 150
Joined: 21. Oct 2017, 15:13

[Solved] Cyclic redondancy check

Post by Leloup78 »

Bonjour,

When copying VM directories to another hard disk, a VM directory cannot be copied.
I tried on another destination, administrator or not, impossible to copy it. I restarted VM. It works fine, but I can't copy its directory. The problem seems to be with the .vdi file.
I tried copying the directories at the command prompt. For file with the extension vdi,
"Error during file creation - Data error (cyclic redundancy check = CRC)".
It seems to me that in the case of a CRC, the VM wouldn't work. No?

Do you have any ideas on how to break this deadlock?

Host: Win10
Guest: Linux

Regards,
Leloup
Last edited by Leloup78 on 6. Jun 2023, 17:34, edited 1 time in total.
scottgus1
Site Moderator
Posts: 20965
Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Cyclic redondancy check

Post by scottgus1 »

As a guess, Virtualbox doesn't check CRC when starting a VM? That would be a lot of data to crunch through just to start a VM.

Sounds like your host disk has a glitch, bad sector, etc in the place where the disk file resides. As a test I'd guess that a disk check on the host might find it, and a disk check in the guest might find it, too.

This is a host OS & disk problem, not a Virtualbox problem.

You could try to add another drive to the VM then inside the OS clone the data to the new disk. If the clone succeeds, you can use the new disk in the VM and copy that to the new host.
Leloup78
Posts: 150
Joined: 21. Oct 2017, 15:13

Re: Cyclic redondancy check

Post by Leloup78 »

Thank you for your idea.
So that gives me an idea. Why not make a VM clone?
Leloup78
Posts: 150
Joined: 21. Oct 2017, 15:13

Re: Cyclic redondancy check

Post by Leloup78 »

I removed the problematic VM from the machine manager list. I then backed up the other VMs that weren't causing any problems. All uploads went smoothly and surely. One VM finished loading.
I thought I'd try your idea. So I added the VM that was causing the problem and launched it. As a result, all the other VMs' backups were interrupted at the same time, signalling a problem. Which makes me think there's a Virutalbox bug or virus or something. No ?
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Cyclic redondancy check

Post by mpack »

VDI has no CRC to check. It also has no physical sectors to go bad.

CRC errors are coming from the host OS and host drive. That's where you should look for the problem and the fix - it really has nothing to do with the software that trips over and reports the problem, i.e. VirtualBox.
Leloup78
Posts: 150
Joined: 21. Oct 2017, 15:13

Re: Cyclic redondancy check

Post by Leloup78 »

I removed the problematic VM from the machine manager list again. I then backed up the other VMs again and waited without doing anything. All loads finished. Great!
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Cyclic redondancy check

Post by mpack »

There was nothing wrong with "the problematic VM". The problem was and is with the host drive that VM was stored on. It is possible to get file corruption errors due to a corrupted inode chain (sorry, can't be bothered to look up alt-windows-terminology), but I would expect that to produce read errors, not CRC errors.
Leloup78
Posts: 150
Joined: 21. Oct 2017, 15:13

Re: Cyclic redondancy check

Post by Leloup78 »

Bonjour and Thank you for your messages and helps.

The signs of weakness were probably due to hard disk problems following a cyclic redundancy check or CRC. I think.
As a result, backups of various kinds failed because of this CRC problem. I suppose.
In addition, with a guest under Linux, I noticed that the external hard disk used for the backup must be in ext4 or NTFS format.

The two methods that worked for me was as follows:
method 1
Boot linux from the installation disk
Download the Test-disk application
Select create image
Select a location in ext4 or NTFS format on an external hard disk.
When the application comes across the CRC problem, it suggests correcting it and replacing the faulty sectors with zeros. Great!
Still using the same application, select restore image.
In addition, there's also a menu in the application for checking the disk. You can also control the disk with Gparted.
Still from the installation disk, you can also use the Disk and Gparted applications to configure the storage disk then
launch

Code: Select all

sudo fsck -p /dev/vg-mint/
method 2
Clone VM

Regards,
Leloup
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