1840   The managed disk has bad blocks.

These are "virtual" medium errors which are created when copying a volume where the source has medium errors. During data moves or duplication, such as during a flash copy, an attempt is made to move medium errors; to achieve this, virtual medium errors called bad blocks are created. Once a bad block has been created, no attempt will be made to read the underlying data, as there is no guarantee that the old data still exists once the bad block is created. Therefore, it is possible to have bad blocks, and thus medium errors, reported on a target volume, without medium errors actually existing on the underlying storage. The bad block records are removed when the data is overwritten by a host.