9 Replies Latest reply: Dec 28, 2009 5:15 PM by dechamp
hooj Level 1 Level 1 (80 points)
i was attempting to do a new time machine back up on my new mac but it won't recognize the usb external hard drive (kaser 250gb). i used it frequently on my old g5 imac, no problems. i plugged the hard drive into my g4 ibook and it recognized it right away. i followed the apple tip of pulling the power plug out of the wall power socket and pulled all the usb cables out as well (i have the wireless keyboard). i let it rest for over 5 minutes and only plugged in my wacom stylus and usb external hard drive. still nothing. and it doesn't show either in disk utility. i also downloaded as per another thread the 3g ntfs system preference but to no avail. the only thing i can of doing is erase and reformat my external on my ibook, but i don't want to risk loosing the data without a back up.

anything else i can try? (before i buy time capsule) thanks

iMac intel core 2 duo 4GB ram, iBook G4 12in, Mac OS X (10.6.2), iMac G5 ALS, iMac G4, tang clamshell, 3 iMacs orange, lime, grape
  • Rick Sr Level 1 Level 1 (15 points)
    Apple OSX Snow Leopard does not work with the NTFS format. Your external hard drive needs to be formatted to either the FAT file system (if you want to include Windows files along with the Mac files) or Mac OS Extended (Journaled) if you just want to store Mac files. If you don't want to lose your info on the hard drive, partition it and just use the empty partition for your Time Machine backup if it's large enough until you can transfer your old files to a different drive.
    Normally, your Mac will recognize that there is a hard disk attached, but if it's in the NTFS format, it won't be able to actually read the disk. FAT is the only file format compatible with both Windows and Mac.
  • dechamp Level 4 Level 4 (3,490 points)
    Actually that's not quite correct. OSX has been able to read a NTFS hard drive and copy files from it for years. OSX can not write to a NTFS natively and requires 3rd party help for that.

    The OP said the drive worked on older Mac's. This is some sort of connectivity issue with the USB interface chipset in the drive's case because the OP said that Disk Utility doesn't see the drive either, and it would have to see a NTFS drive in order to format the drive for MacOS.

    If the OP was already reading and writing to the drive on a G4 and G5 Mac then there shouldn't be any format problem for the Intel Mac to at least see and read from the drive.

    I'd try using a different USB ports on the new Mac. I've also seen cases where using a USB hub - not normally recommended at all - can get a Mac to see a drive.

    There have been a few reports of some drives from Western Digital and Buffalo that did not work with SL, but did with Leopard. Check for firmware updates from the Vendor. You could also put the drive itself into a newer compatible (most are) external case.

    This drive should also be looked at with Disk Utility in Leopard to see what the Partition Scheme of the drive really is. Is 3GFS really required at all?
  • Rick Sr Level 1 Level 1 (15 points)
    Strange... my iMac running Snow Leopard can neither read or write to a NTFS formatted external drive. But it does fine with a FAT format on the same external drive. Hmmmmm.
  • hooj Level 1 Level 1 (80 points)
    thanks for your assistance. i just checked again by plugging the external into my ibook g4 and checked how it was formatted - mac os extended (journaled). i also changed the usb ports on my intel imac and it still won't show. can't find any drivers from the kaser website. my ibook hard drive isn't big enough to hold the time machine back ups. also, i don't run any windows programs.

    i have an idea, not sure if it will work and it will have to wait a couple days until i get my firewire back from a friend, but this is what i'm thinking: my intel imac has a 1tb hard drive. could i use target mode between my imac and ibook? with my ibook i'd attach the external hard drive, then using the firewire and target mode start it up. hoping that the ibook hard drive and the attached external hard drive would show on my intel mac for which i could copy over the external back ups onto my imac. once completed, i could erase and reformat the external on my ibook and then try again on my imac to see if it appears on my desktop. do you think this might work (even though it is correctly formatted already?)

    other than the above, i may just go buy a 1tb time capsule, though i am a little concerned about their reliability from the negative posts on the apple web page for this product.

    cheers and thanks
  • dechamp Level 4 Level 4 (3,490 points)
    i just checked again by plugging the external into my ibook g4 and checked how it was formatted - mac os extended (journaled).

    Then the 3GFS software is not required at all.

    i have an idea, not sure if it will work and it will have to wait a couple days until i get my firewire back from a friend, but this is what i'm thinking: my intel imac has a 1tb hard drive. could i use target mode between my imac and ibook? with my ibook i'd attach the external hard drive, then using the firewire and target mode start it up. hoping that the ibook hard drive and the attached external hard drive would show on my intel mac for which i could copy over the external back ups onto my imac. once completed, i could erase and reformat the external on my ibook and then try again on my imac to see if it appears on my desktop. do you think this might work (even though it is correctly formatted already?)


    I use Target mode on a regular basis for mounting the internal drive on a Mac to transfer or salvage data. I don't know if you will be able to connect to an external drive on the Target computer. There's not usually any reason for this and I don't know if the Target Mode will enable the Logic board to deal with the USB ports and transfer data. I kinda doubt it, but other more experienced users can jump in here.

    I don't think the problem with your external drive is the format, since you've already checked it and it is already formatted for a Mac. Intel Mac's will mount drives formatted by a PPC Mac with no problems, unless your OS doesn't support the chipset in the USB case that connects to the drive. There are some USB drives that are known to not work well with SL but worked fine with Leopard.

    You can buy a cheap USB case (about $30) and move the drive from the old case to the new case, or buy a USB to IDE adaptor cable (about $20), or you can buy a larger external drive that will work on the iMac and use the G4 to transfer the date from the old drive to a new one. Or you can take both drives to a friend with a Mac and use Disk Utility to restore the USB drive to a partition on the Firewire drive. That doesn't fix the USB drive to work with your new Mac, but unless the vendor comes out with a firmware fix, I think that's a lost cause anyway.

    other than the above, i may just go buy a 1tb time capsule,


    I would not be getting a Time Capsule to back up a single computer. Wireless backups are a lot slower than FireWire or USB (of course, it's the initial backup that takes so much time). If you do have several Mac's that need a TM backup volume, then the Capsule can help you out. It is supported by Apple (and there are a lot of users here in the forums). I'm using a ReadyNAS device for network backups, but it is not supported by Apple, and I have to rely on NetGear for fixes if an OS update breaks my backup system.

    BTW, it's a good chance that a TC device will be able to see and mount your USB drive. The incompatible chipset problem with some drives seems to be limited to the USB drivers in SL which the TC is not running. That's why I said that a USB hub may also let you see your drive, the problem is there's no guarantee's...
  • dechamp Level 4 Level 4 (3,490 points)
    Yep, it is strange that you can't see a NTFS drive on your Mac. If that was true with everybody, then we would be out of luck if we wanted to re-purpose an old drive to use on a Mac. Have you verified that the drive is NTFS or did you assume it wasn't Fat because it didn't show up on your Mac?

    FAT32 has been available for read/write access in OSX forever, but from what I understand, Apple has not decided to implement writing to NTFS because the specifications are not published by Microsoft. There were rumors about Apple enabling write support in SL beta's, but it never made it to a shipping product. Apple is pretty cautious about data transfers and it shows when they 'tighten' the requirements for existing technologies like USB. Some chipsets just don't measure up.

    I wonder if the problem with the NTFS drive is actually a problem with the external case and the USB chipset used to connect the actual drive to the cable. The actual hard drive is either IDE or SATA and the chipset manages the communication between USB and IDE/SATA interface on the drive.

    If it's important, you could try getting a different case for the drive. Windows machines don't seem to push the drives as much as a Mac, and all of the external cases I've tried do work on a PC (although throughput speeds can vary a lot from case to case). You would still need a 3rd party program to write to the drive, but they seem to work pretty well.
  • hooj Level 1 Level 1 (80 points)
    strangest thing! after reading your post dechamp, about "some usb drives not working with SL", i thought that perhaps i should dig out an old usb adapter for 4 additional usb ports (from the days of my indigo imac). low and behold, i plug the thing in, power it up, plug the external hard drive usb into it and.... ta da...
    the external now shows up on my desktop!!!! zut alors!

    i guess i will have to erase the external and start over with time machine as it doesn't recognize that i have most of backup on it - it wants to do a complete new backup. to bad it doesn't know what is there already and can just continue on.

    i appreciate your help dechamp and everyone else. looks like i have a work around. cheers
  • hooj Level 1 Level 1 (80 points)
    currently solved with a work around - a powered external usb port. yeah!
  • dechamp Level 4 Level 4 (3,490 points)
    Yeah, I've read it's possible. Could be because your Mac is not providing enough power on the USB port for the drive, or the Mac likes the chips in the hub better than the chips in the case. Either way, it's connected.

    Now, is that old hub USB1 or USB2...