On Sun, Apr 8, 2012 at 1:13 AM, Macs R We <[email protected]> wrote:
> I was given a WD Passport for Mac today by a fellow who says he was tired of > trying to get it to work. I took it home and hooked it up, and experienced > the most bizarre symptoms. If you have any reason to suspect a drive, the best strategy is to run the vendor's diagnostics (generally requires Windows and a SATA interface) before wasting a lot of time on a lost cause. I have two 1TB LaCie Stark drives that worked flawlessly for a couple years, one used for Time Machine backups of a macbook pro. When I first got the drives I had problems with the drive disconnecting while in use, but after switching USB cables the drives worked without problems for over a year. Last week I came back from a month of travelling and neither drive worked. The Time Machine backup started normally and then I got a popup saying the drive had been removed improperly. I tried to repair the drive using DIsk Utility, which said the drive couldn't be repaired and should be erased and formatted, which I did. After that the backup ran, but it is not encouraging to have a backup volume suddendly go bad like that. In the last week of my travel I had several USB thumb drives come up with corrupted files. It may be significant that the USB ports on the MBP have been heavily used (mostly transferring files via USB thumb drives). USB connectors now go in and out with very low resistance, so may not be making a reliable connection. The other drive is used as a spare boot disk and for data. It too came up with the popup saying the drive had been removed improperly, and again Disk Utility was not able to repair the volume. I reformatted the drive and tried to "clone" my system disk, but again got the the improper removal message and was not able to repair the disk. At this point I decided to see how the drive worked with a linux system. I reformatted the drive on linux and was able to transfer 3/4 TB of data to it without problems. All this indicates that something (power glitch or cable/connector issue?) caused the drive contents to become corrupt beyond the repair capabilties of Apple Disk Utility, but the drives themselves seem to be fine. > The drive showed up on the bus, whether FW800 or USB, exactly the same way. > There was no "couldn't mount" message, but the volume wasn't mounted. > However, the volume's name showed up correctly in Disk Utility, only in > gray. When I asked Disk Utility to mount the volume, it said there was > something basic wrong with it, and it needed repair. When I attempted to > repair it, it would say, "Unmounting volume" and then just spin forever. I have searched for postings with similar symptoms. Some people blame power management settings that spin down USB drives when the system is idle, but my system has that option disabled. > Disk Warrior immediately complained about the disk, saying that it couldn't > mount it (or maybe it was dismount it, I forget) and eliminated itself > entirely from consideration as a recourse. > > Drive Genius 3 scanned the whole drive at 100% good, zero bad blocks, but > when asked to initialize it did the same thing Disk Utility did when asked > to repair or initialize it: it hung unmounting it. Same for native diskutil > in Terminal. > > After Googling a bit, I learned that WD had a drive diagnostic tool > available for Windows, so I booted up Windows and downloaded it. It said > the drive was hunky dory -- of course, Windows didn't have any way to mount > the volume. The diagnostic tool offered a choice to zero out the first and > last million disk records, so I chose it. When I rebooted OS X, shazam -- > the OS complained that the drive needed initialization, and Disk Utility had > absolutely no problem initializing it. The vendor tools should be the first thing you try with problem drives. These often create a detailed report (that you need to get a return authorization for warranty replacement -- recently I find that drives die a few days after the warranty has expired, but it is still useful to know when there is no point trying to reformat a drive that is giving problems). Certainly it is a waste of time trying to use a drive the vendor considers "failed". > My first thought was, perhaps the entire drive was encrypted. But I can > guarantee you the fellow who gave me the drive doesn't have the chops to do > this himself. Then I thought, WD has a drive management suite that comes > with their drives that knows how to do this, and some of their drives have > actual hardware support for it. But this drive (a WD5000MT) doesn't have > that capability or work with that suite. > > Any ideas as to what would cause a drive to act this stupidly? Dodgy cables/connectors or power glitches resulting in corruption beyond the repair cababilties of Apple's tools. Whenver possible I use UPS power for external USB drives. It would be interesting to see some systematic experiments with the ability of various filesystems to recover from problems caused by "accidental" USB cable removals and/or power outages. -- George N. White III <[email protected]> Head of St. Margarets Bay, Nova Scotia _______________________________________________ MacOSX-talk mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/macosx-talk
