A former Microsoft employee, released a couple of interesting tools for Hyper-V: “VHDCopy is a command line utility that significantly reduce time required to copy large virtual hard drives files by skipping unnecessary portions of data (like hibernation file) inside VHD itself. It only works with offline VMs and fixed VHD files up to 148GB that’re formatted with NTFS. It performs 2x-10x faster than other copy operations, like System Center Virtual Machine Manager (SCVMM) check-in/check-out operation or manual copy command performed by an admin, by reducing disk I/O operations from 20% to 90%. And VMProv is another command line utility that works with VHDCopy, allowing administrator to use VM while VHDCopy’s still performing copy operation. Every operation made during this timeframe is managed by a mini file system filter driver that’ll apply changes to copied VHD file as soon as copy ends.
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