Yes. All Mfsadd is doing is partitioning the drives, which only takes milliseconds. That's normal. It doesn't know what to do about the second drive. What has happened is exactly what you did. You powered up the TiVo with a missing hard drive. Since it cannot find the second drive, the TiVo has only two options: either stop or repartition the system to use only a single drive. Rather than making the decision itself, the TiVo (wisely) leaves it up to you. Had you simply shut down the TiVo and plugged in the external drive, you would have been fine. As it is, you have to re-do the marriage. That's safest. It's not surprising. You may need to wipe the drive partition on the external drive. Having one of the pair being married and the other divorced is confusing WinMFS. You ran mfsadd. As far as the second drive is concerned, it is married. The first drive was divorced, however, without the second one's participation. You should not have divorced the drive. You should have simply plugged the external drive into the TiVo. It's possible running mfsadd again will fix the situation, but you may need to repartition the second drive, first.