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'Internal error: invalid bitmap index' When trying to do cluster resize.

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Posts: 1
Comments: 1


I am using the trial version to see if it works for what I need before I buy, but I'm not having any luck. I am trying to resize cluster on ntfs partition in windows 2012r2. I am hitting this error:

Code:  9,764,885(0x950015)
Message: Analyzing has failed.

Code:  3,539,358(0x36019E)
Message: Fdisk has failed to analyze.

Code:  1,060,920(0x103038)
Message: Probe has failed.

Code:  458,753(0x70001)
Message: Internal error: invalid bitmap index

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Forum Moderator
Posts: 122
Comments: 4637


Hello liquid smoke,

I'd start with checking the prerequisites from Acronis Disk Director: Changing Cluster Size and running chkdsk /r /f against a disk in question. If the operation still fails, try to perform resizing using a bootable media that will exclude any OS related issues. Should the issue persist, please open a support ticket.


Posts: 0
Comments: 1


I am using the workstation version of ADD 12.5 on Windows 10.

I have encountered the same set of errors and logged a case with technical support after following the above advice(#03529617).



ADD 12.5 in Windows 10 was able to change the cluster size of the 100GB C:\ volume from 4KB to 8KB successfully. This required a reboot into the Acronis Boot environment to apply the change.

However I was unable to attempt a change of cluster drive on the Y:\ volume (4x4TB spanned dynamic volume).

Following up on this error, I completed a successful chkdsk /F /r which completed in 36 hours and found no errors.

This did not resolve the issue.

I then created a WinPE Bootdisk and attempted to conduct the same operation. I encountered the following additional errors:
Unable to create volume snapshot.
Block count limit of snapshot manager has been exceeded.

I then created a Linux bootable media and attempted to make the same change.  Using this environment I am able to commit the change from 4Kb to 16Kb cluster size on the volume, and apply. But some time afterwards the system reboots into the OS with no changes having been made.


Forum Moderator
Posts: 122
Comments: 4637


Hello BShaw,

I see that your support ticket has been escalated to the higher level and one of our expert engineers is working on it. Please share the results of the investigation with us.