Microsoft informs an issue for customers running Windows 7 and Windows Server 2008 R2 in which the platforms can corrupt disk volumes and lead to data loss on computers with HDDs larger than 2 terabytes (TB). "This issue occurs because of the crash dump disk driver (Diskdump.sys) cannot address more than 2 terabytes of disk space. Diskdump.sys driver can address up to 2 to the power of 32 sectors. If the sector size is 512 bytes, the driver can address up to 2 terabytes of disk space. If the actual offset is larger than this limitation, the driver incorrectly truncates the offset and saves data to a wrong location. Therefore, one or more volumes on the disk are corrupted," explains Microsoft in KB2249857.
A supported hotfix is available from Microsoft.