In this series, we’ve seen how drive geometries and components necessitate special mapping file systems to enable the drive to know where each writable surface on the drive is located, to position the head under each sector, write to the sector, and read it back.
We also looked broadly at many of the systems that make this magic possible. Various versions of File Allocation Table (FAT) designs have been created, adding functionality, and also adding the ability to support the rapidly increasing capacities of hard drives. NTFS has also gone through a number of upgrades, and Linux may use any of a few different file systems created for the various distributions of Linux.
File systems create partitions, which can be roughly described as an area on the physical hard drive that can be used as a ‘logical’ hard drive, or for other purposes. For example, a single physical hard drive in a computer can be split into two partitions – which in Windows may be represented as a C: and a D: drive. Your physical drive may have other partitions that are used for such things as operating system recovery or backup of partition information.
Partitions can be configured in a variety of formats – and a partition formatted for one operating system (Mac OSX, for example) may not be natively compatible with a computer running a different operating system, or vice versa. What we mean by ‘natively compatible’ is to say that a drive with a partition for a Mac computer would work without problems when attached to a Mac, but may not work at all (or without special software) when connected to a PC running Windows.
In spite of these incompatibilities, various ways exist to copy or move data across drives with incompatible formats. Perhaps the simplest way is over a network. With, for example, a Macintosh machine and a Windows machine on the same network, and both machines allowing discovery on the network, it should be fairly easy for a user to access the drives on the other machines. You should be able to select the files you want to copy, and copy them over the network. Be aware, though, that even though you may be ABLE to transfer files over a network, you may still be unable to open or view the files.
Another method is what they used to call SneakerNet many years ago. Originally, this referred to using a 1.2 MB (or even a 360 kilobyte) floppy disk, putting it into the computer with the file you wanted to copy, writing the file to the floppy disk then walking it over to the target computer where it would be copied onto the target computer.
SneakerNet has changed a lot over the years. Today, a 16 GB, 32 GB, and maybe an even larger USB Flash drive can perform the similar operations, providing literally millions of times as much capacity as that lowly floppy disk. There may still be issues related to copying files using this method from computers with different file systems. Although Flash drives are often labeled as Mac AND Windows compatible, some users still report that transfers from one file system to another using a flash drive does not always work.