In my data center practice, I’m occasionally stuck moving very
large files. There was a time when it was rare that I’d see a file larger than
a CD or DVD’s capacity, but nowadays, I often see multi-terabyte files. There are a couple of reasons why this is the case.

In my professional virtualization practice, I advocate for people to transition to disk-based backups. The other part
of this is my emerging practice of working with Hyper-V virtual machines. For
me, I’m always moving things around in Hyper-V, and files like a VHD or VHDX
disk are actually quite large–much like that of the disk-based backup world.

Simply using Windows Explorer, PowerShell, Robocopy, or
the now quite dated RichCopy
are good, but myself and others in the virtualization community have come to
fancy TeraCopy. It’s free for non-commercial use, so
it’s very easy to try. The paid version, TeraCopy Pro, comes with additional

How to use TeraCopy

TeraCopy installs very easily and can optionally be added to
the right-click context of Windows systems, which is how I recommend using
it. After this is complete, a TeraCopy job can be done as shown in Figure A. (TeraCopy supports Windows 8 x64. The example in this article is Windows Server 2012 R2. Click the images to enlarge them.)

Figure A



TeraCopy provides you with the option to move the files
vs. copying them. Once the files are added and the target path is selected,
the jobs are underway (Figure B).

Figure B



One of the best aspects of TeraCopy is the optional built-in
hash checking (Source and Target CRC in the interface) that is done with the
files that are moved or copied. It’s great that the Target is checked back
against the source afterwards in the case of a copy, because you can check to make sure they match. Don’t underestimate the file of hash or CRC
check of a file, especially very large files. If you do the verify step on
TeraCopy, be prepared for it to take a while.

In today’s world of storage,
there are a lot of different products out there–everything from deduplication
(typical for disk-based backups) to converged systems to build-your-own NAS
systems–and there can be varied results. Figure C shows the hashing
being matched up after the copy.

Figure C



One of the best aids to a busy (or lazy) administrator is possibly the ability to pause a job. Besides the lazy aspect, this may be very
beneficial if you have limited bandwidth, and the task can’t run
during the business day. That
leads me to my wish list of a bandwidth limiter on the I/O, but TeraCopy’s
objective is to move files fast.

Join the discussion

Have you tried TeraCopy or another tool? What kind of catch points have you had with moving or copying very large files? Share
your recommendations and experiences in the discussion.