Removable USB drives and camera cartridges have historically used the ExFAT filesystem, as this filesystem type is simple and available across multiple operating system platforms, including macOS, Linux and Windows. iodyne Pro Data allows you to format a container using any filesystem type supported by your operating system: including ExFAT. However, we also feel obliged to warn you that ExFAT is not a good choice for general-purpose containers on your Pro Data, unless you are in a situation where your specific interoperability needs absolutely require the use of ExFAT. ExFAT is not able to guarantee automated recovery in all situations, for the reasons explained below.
When you write files in a filesystem, the filesystem software running on your computer has to be prepared for storage to lose power or fail in the middle of a sequence or reads or writes. A standard technique for solving this problem is to keep a journal of updates, that can be replayed automatically when the filesystem is recovering after unexpected power loss or failure. Journaling File System designs are used in all modern filesystems, including ZFS, Apple Filesystem (APFS), and NTFS.
iodyne adds unique resiliency features to the firmware of all of our storage devices, to provide even stronger guarantees for safety and fast recovery than a journaling filesystem can provide alone. These include RAID-6 to protect your data from up to two SSD failures, and transactional semantics — including atomicity, preservation of write ordering, and elimination of the RAID write hole — to ensure that containers are always in a consistent state from the filesystem's point of view. What this means to your filesystem is that after an unexpected power loss, computer crash, or hot-plug event, the contents of a container always correspond to a valid prior state of the filesystem. For example, if the last three changes made by the filesystem were a, then b, then c, then the container will have either a, or ab, or abc — it will never have just ac, bc, b, or c, any of which would violate the filesystem’s logical timeline of events. This guarantees, in particular, that the filesystem’s journal is always valid, and that all writes that have cleared the journal (as well as the journal itself) are on fully stable, encrypted, checksummed, RAID-protected storage in your iodyne device.
Alas, poor old ExFAT is not using any type of journaling, meaning that it is not able to guarantee automated recovery in all situations. Depending on what the filesystem is doing when you unexpectedly lose power, you might have no issue, you might have to manually recover the filesystem using Disk Utility's First Aid, or you might in fact lose data from recent operations. So ExFAT is not something we recommend you use as the primary filesystem for your containers, even when combined with the strong transactional and RAID guarantees made by Pro Data.
Use ExFAT sparingly, when you need it for interoperability. On macOS, use APFS for best performance and reliability of your containers. On Windows, use NTFS for best performance and reliability of your containers. Contact iodyne Support to discuss any technical questions or help plan your workflow.