Robocopy results exceed source

Question

_{Thursday, December 13, 2018 11:14 PM}

Robocopy was being used to copies files from C: of the old system to a general area on  partially used drive on a new system.

Source: 351 GB used

Destination: 1.15 TB Free Space

Robocopy command.  It was run as Administrator.  

robocopy L:\ s:\w7_c\ /mir /r:0 /w:0 /a-:sh

After 3:24:39 the destination drive was full

53.713 gb failed to copy.

Destination drive:

Used space 1.81 TB

Free Space 0 bytes

How does the destination drive with 3 times as much space as the source drive data run out of space?

After the folder containing the copied files was deleted, the destination drive had the original free space.

Thank you.

All replies (2)

_{Friday, December 14, 2018 12:36 AM}

Hi,

There might be a few things, I would check the following:

• Check the Allocation Unit Size of both disks if they are the same or not, you can check this by running the following command in a Command Prompt (Admin):

fsutil fsinfo ntfsinfo C:

• Try adding the /XJ to exclude junction points.

• Is the source drive compressed? (If this is a server then check if data deduplication is enabled).
• Some files might be using NTFS compression on the source while they don't on the destination.

You can use the TreeSize (free) to compare both drives:

https://www.jam-software.com/treesize_free/

Best regards,
Leon

Blog: https://thesystemcenterblog.com LinkedIn:

_{Sunday, December 16, 2018 11:53 AM}

Hi,

Please refer to the following link to see if any help:

Robocopy is using more storage than source drive...what??

https://www.reddit.com/r/sysadmin/comments/5bv3zq/robocopy_is_using_more_storage_than_source/

Please Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

Best Regards,

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