You can use a special operating system SystemRescueCD for virtual machine maintenance, diagnostics and troubleshooting after a failure.
In this video we will tell you how to start a virtual machine in recovery mode using its image.
Detailed information about virtual machine recovery mode in VMmanager is available in the documentation section Recovery mode (ispsystem.ru)
SystemRescueCD documentation: http://www.system-rescue-cd.org/manual/
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