﻿id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host
15983,VDI image resize yields unbootable VDI,markusvm,,"Using 
{{{
VBoxManage modifymedium disk <file> --resize <size>
}}}
in VirtualBox 5.1.6 r110634 turns the VDI image (no snapshots used) into an unbootable medium, i.e., the MBR is garbage.

In my specific case, the capacity of the image before resize is 64000 MBytes (61599 MBytes size on disk). I tried 68000 MBytes and 72000 MBytes as resize goal. Both operations complete almost instantly without error and
{{{
VBoxManage showhdinfo <file>
}}}
outputs the correct capacity and unchanged size of disk.

I used resize before with other VirtualBox versions on this image and it was never a problem.",defect,closed,virtual disk,VirtualBox 5.1.6,fixed,,,Windows,Linux
