Why do files break when added to a 7z, WinRar archive?

Question

Iron

I have been experimenting for half a day, I can not understand the reasons.
I archive the image of the virtual machine in which Win10 is installed. The first big file (vmdk) weighing 3.5 giga beats. The total volume is 9 GB. The file is compressed from NTFS to NTFS partition, tried to transfer files to another hard drive.
Windows 7 Pro x64, 7z 16.04 x64, WinRar 5.50 x64.
The RAM is 8 gigabytes, I don’t particularly complain about the stability of the system, though it’s crammed with protective software in order.
In any case - under almost all conditions during the archive check - a CRC error.
I create an archive with maximum compression in 7z (LZMA). Check - CRC error.
I create a RAR5 archive with maximum or normal compression - CRC error.
I compress ZIP from the same 7-zip file manager with minimal compression - everything is fine.
The compression process takes about half an hour.
Otherwise, the computer does not show itself in any way, but a repeating (repeatedly) error on the same operation.
How to identify the main culprit?

Answer 1

Test memory for errors.