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exFAT mounting problem

Hi, I'm trying to mount an exFAT harddrive via usb. The disk is recognized and show in the disk utility, but i cannot activate it. The only error I get is in the Console :

28.02.11 20:38:36 kernel exfat: bytes per cluster (4194304) > MAXBSIZE (1048576). Can't mount.

Any chance of getting access to the drive? It mounts perfectly under Windows 7.

Thanks!
Regards,
aixxo

Macbook Pro, Mac OS X (10.6.6)

Posted on Feb 28, 2011 11:50 AM

Reply
17 replies

Nov 7, 2017 1:15 PM in response to aixxo

Good to know but I wish I had known sooner. I've been formatting to exFAT for a while assuming that everything would be Mac/Windows compatible. In fact that's the only reason I have been formatting exFAT and now I find out it has to be formatted exFAT to a specific cluster size! I'm using Parallels to run Windows 7 to access my exFAT drive in Mac OS as a workaround because moving all my files off my 6TB drive so I can re-format to 1024 cluster size and move them all back again isn't feasible at the moment.


Does the same apply for LG TVs? I tried inserting an exFAT-formatted thumb drive into an LG TV's USB port and it wouldn't read it, so my conclusion at the time was that it was because they were only FAT32 compatible but now I wonder...

Feb 28, 2011 12:03 PM in response to aixxo

I know it has the format option, but did not know if it also had read capability.

A problem I've often come across in the forums is that sometimes a drive formatted on one platform does not work correctly on the other. It isn't just limited to the Mac or to a PC. I have no idea if a solution has been found other than trying to format on the other platform. Wish I had more to offer.

Nov 10, 2011 4:54 AM in response to aixxo

Perfect thanks. I got it working too with 1024, had issues with 4096 cluster size.


Thanks for the link. Hopefully Apple will improve exFAT soon.


I have a 3TB USB drive and want to use with Mac and Windows, exFAT was the only real option.


NTFS can be used with Mac, but not with all Macs as requires that plugin installed. Where as exFAT can be used with any 10.6.5 Macs which is perfect.

Jan 23, 2013 11:28 AM in response to aixxo

Hi, i have a similar problem only using USB 3.0 with external hard drive although Disk Utility won't recognise this drive. Disk was formated in exFAT, 1024 cluster size. Works fine on Win7 through USB 3.0 and USB 2.0 port.


Tried pretty much everything. Is there any chance to make this external drive and mac combination work?



Thanks, Nino!

Mar 30, 2014 7:55 AM in response to aixxo

I am runing Mavericks and I tried formating one drive in Exfat and a USB 3 thumb drive and both of them when I try to copy large files on them they crash while in the middle of the transfer and it unmounts the drive and says the drive was not ejected properly. Then When I unplug the drive and plug it back some times the drive wont event show up in finder. I can see it in Disk utility but it looks as if the partition has gone. Some times the only way to reuse it is to format it again i Exfat, but then the problem happens again. Has anyone had this problem in Mavericks. I am using a Macbook pro retina display upgraded model late 2013.

exFAT mounting problem

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