Ufs error updating
To access it, select a virtual machine from the list on the left and select "Show logs..." from the "Machine" window.
The release log file (VBox.log) contains a wealth of diagnostic information, such as Host OS type and version, Virtual Box version and build (32-bit or 64-bit), a complete dump of the guest's configuration (CFGM), detailed information about the host CPU type and supported features, whether hardware virtualization is enabled, information about VT-x/AMD-V setup, state transitions (creating, running, paused, stopping, etc.), guest BIOS messages, Guest Additions messages, device-specific log entries and, at the end of execution, final guest state and condensed statistics.
In case of crashes, it is very important to collect to create a dump of a complete virtual machine; see Section8.40, “VBox Manage debugvm”.
For network related problems, it is often helpful to capture a trace of network traffic.
In order to work around this problem (the true fix is to use a faster file system that doesn't exhibit such unacceptable write performance), it is possible to flush the image file after a certain amount of data has been written.
Virtual Box provides an ability to capture network traffic only on a specific VM's network adapter.
Refer to the network tracing article on the Virtual Box website Use the VM debugger at your own risk.
If, for example, Internet connectivity is lost due to external issues, virtual machines will be affected just as much as physical ones.
If a true Virtual Box problem is encountered, it helps to categorize and isolate the problem first.