I'm troubleshooting a new external hard drive. It isn't readable on the computer it was bought for (my mother's). It worked fine, at first, on my computer with OS X installed but she has Parallels and a leftover installation of Bootcamp. When we setup Parallels she tried to remove Bootcamp but the removal failed so it's still sitting there as we left it. I don't know if the failed removal is contributing to this problem (it's sitting on 300MB of unusable space).
On her Mac, the external drive doesn't show up in Finder (on Windows it isn't in Device Manager or Disk Management at all, even to show that it needs a driver or formatting), it only shows up under Disk Utility and then the indented subentry is greyed-out. It shows 0 bytes free but on my Mac it was not greyed out and shows its full 5TB are free.
I tried running Erase to reformat it to MSDOS FAT (from Windows NT, that it came with) but that has failed.
In Disk Utility, the Info that seems relevant:
Writable No Available Space (purgeable + free) 0 Purgeable space 0 Free space 0 Can be verified 0 Can be repaired 0 Bootable 0
Initially First Aid said:
Checking prerequisites Checking the partition list Checking the partition map size Checking for an EFI system partition Problems were found with the partition map which might prevent booting Operation successful.
When Erase failed:
Unmounting disk Creating the partition map Waiting for partitions to activate Formatting disk3s2 as MS-DOS (FAT) with name S B+ 5TB Mounting Disk Could not mount disk3s2 after erase File system formatted failed. Operation failed...
Now running First Aid:
Repairing file system. ** /dev/rdisk3s2 Invalid BS_jmpBoot in boot block: 000000 File system check exit code is 8. Updating boot system partitions for the volume as required. File system verify or repair failed. Operation failed...
I have tried plugging it into my Mac again and it has the same Info, but slightly different error when I ran Erase:
Unmounting disk Erasing newfs_msdos: S B+ 5TB: bd volume name Mounting disk Could not mount disk2s2 after erase File system formatter failed. Operation failed…
I realize the disk name of
disk2s2 is only different because the two computers are naming it differently. Also,
S B+ 5TB is the shorthand for the name I was giving it: Seagate Backup+ 5TB (their own troubleshooting page was helpful to a point).