If you do not want to use MULTIBUF , you can switch it off and write plain tar(1) or afio(1) archives.
Unfortunately, the many new features, especially the secure multivolume support, required some changes to the way archives get written to the tape. However, KBACKUP is able to autodetect whether MULTIBUF has been used in archive creation and therefore is still capable or reading archives that have been created by earlier versions of KBACKUP . It is currently not possible to restore multivolume archives that have been created with older versions of KBACKUP . As they were somehow unreliable anyway, better use a version newer than 1.2 to make new backups.
To restore old multivolume archives, created with version 1.0 or 1.1, you have to use tar(1) or afio(1) manually.
Restoring any archive manually (optionally using MULTIBUF ) is always possible, anyway.