If the last sync operation was interrupted and not finished correctly (eg. the application crashed) and the bad blocks fixing procedure was in progress, the bad block recovery files may be left over. In such case bad blocks might have been cleared and zeroed, but the correct data from these blocks was not recovered (not copied from a healthy replica), so the recovery files MUST NOT be deleted manually, because it would cause a data loss. Pmempool-sync should be run again with the `-b' option set. It will finish the previously interrupted sync operation and copy correct data to zeroed bad blocks using the left-over bad block recovery files (the bad blocks will be read from the saved recovery files). Pmempool will delete the recovery files automatically at the end of the sync operation.

Using this option may have limitations depending on the operating system. For details see description of the CHECK_BAD_BLOCKS feature in pmempool-feature(1).