By default, power save options are enabled on Windows virtual machines. After 15 minutes of inactivity, the virtual machine goes to the sleep mode. VMware detects that the virtual machine is in the sleep mode and suspends it. When the virtual machine is suspended, the USB drive connected to it is automatically disconnected from the virtual machine.
This issue occurs because the Windows virtual machine did not have an opportunity to safely remove the USB device and save data writes to the device. This causes a loss of data or corruption of the USB disk.
To resolve this issue, modify the power options of the Windows virtual machine, so that it will not enter sleep mode.
To modify the power options in a Windows Vista/7 virtual machine:
- Click Start > Control Panel > Power Options.
- Click Change when the computer sleeps link.
- Set the Put the computer to sleep option to Never.
To modify the power options in a Windows XP virtual machine:
- Click Start > Control Panel > Performance and Maintenance > Power Options.
- Change the System Standby option to Never.
Based on VMware KB: 2009508