Item Subject: cc:Mail Text I've inquired a bit about the whole "head (mis)alignment" problem on the DDS drives. Following is the response from one source. (Comments in square brackets [] are mine.) FWIW. --Glenn Cole Software al dente, Inc. [log in to unmask] Seagate (Conner) and HP owned this problem [but see below], and to the best of our knowledge, it is something that has only occurred in any meaningful frequency in the case of their drives. Your questioner is correct about the issue, and it relates specifically to those manufacturers drives listed above whose drive heads shift off azimuth in such a way that the data tracks are laid on the tape at too ablique an angle for a properly adjusted drive to read them. You make your backups on the out of adjustment drive and occasionally have to restore data - no problem. Your first notice of the problem occurs when you take a tape made on one of these mechanisms to another drive to read. Even the same make and model in proper alignment can't read these tapes, and then, when that original unit finally gives up the ghost and has to be replaced, all those tapes are essentially lost. While there are similar problems that can occur on other tape platforms, I believe that it has been largely solved with new drives from virtually all manufacturers for quite a long time, and it's a problem that still does rear its head occasionally. Moreover, I believe that this single problem did more to contribute to the bum rap that DAT took in the marketplace 2-3 years ago, than any other single problem, including [one company] knowingly shipping bad 120MB DDS-2 media. [then, in a follow-up msg...] My reference to HP is heresay, as we have not specifically handled HP DAT units on an integration basis or as an OEM of HP. The source I'm referring to had the problem with both Seagate (or Conner, as I can't remember the exact time frame of the problem relative to the purchase of Conner by Seagate) HP DATs which had both exhibited the same problem. He alluded to fairly widespread problems within the world of HP's 4mm domain and I'm guilty of repeating it as if it were my own experience. Subsequent to his experience we've been told the same thing by several other sources. The other caveat is that while the tapes made on an out of adjustment drive, during the time that the drive is out of adjustment, will be lost if that particular drive fails, the misalignment occurs over some period of time so that we may not be talking about every tape ever made, and conversely, those tapes made when the drive is slightly misaligned may not still be readable when the drive drifts into gross misalignment.