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DISKSHADOW And VSSADMIN control shadows. But what's a "shadow"? Good question.

A shadow is copy of file or a volume. This can be done even while the file is in use. The proper name for this is Volume Snapshot Service  or Volume Shadow Copy Service or VSS. And it works at a block level (rather than a file level).

There are a couple of parts to this but the heart of the technology is the VOLUME SHADOW COPY SERVICE which performs the actual copy.

The transfer of the data is called a PROVIDER. While Windows comes with its own PROVIDER, other software companies can create their own providers. An example of a built-in PROVIDER is SYSTEM RESTORE or PREVIOUS VERSIONS for a file or folder. An example of an outside software company is SHADOWPROTECT. While SHADOWPROTECT is an outside company, it still relies on VSS to create the shadow on its behalf. SHADOWPROTECT does not create its own shadow.

The shadows are traditionally managed by VSSADMIN. Here's how to show all PROVIDERS in either powershell or command-line:

• vssadmin list providers

And here's how to show the SHADOWS:

• vssadmin list shadows

And here's how to show the SHADOW storage:

• vssadmin list shadowstorage

VSSADMIN is not the only tool. Another tool gives more info. That is DISKSHADOW. DISKSHADOW is a interactive command interpreter like DISKPART. What I've found is that DISKSHADOW is a more accurate and more powerful tool.

Here's how to enter DISKSHADOW interactive:

• DISKSHADOW

Here's how to show all PROVIDERS:

• DISKSHADOW> list providers

Here's how to show all SHADOWS:

• DISKSHADOW> list shadows all

It will show all the SHADOWS, if it is created for a builtin provider or for an 3rd party provider. And it will show the provider ID for each shadow.

To add info, you should be able to limit the size of a shadow:

• -computer-management
• -right-click SHARD-FOLDER (on the left-hand side)
• -click ALL-TASK > CONFIGURE-SHADOW-COPIES
• -click SETTINGS for each drive and adjust the size as you see fit.

NOTE: you can also do this on the DISK-MANAGEMENT snap-in.