4 ms·

what are the alternatives though? NTFS? Won't work on Mac HFS+? Won't work on Windows EXT4? Won't work on Mac or Windows

alt227 2y ago
exFAT is generally considered the more modern replacement.
- robinsonb5 2y ago
  But is still legally encumbered. FAT32 might have its limitations but it is at least small and simple enough to be implemented in a few K of boot code. That's the reason I still use it with FPGA projects.
- Kwpolska 2y ago
  ExFAT is a thing, but it’s less data-safe than NTFS (and than FAT32), and Linux distros might not ship drivers out-of-the-box.
  - lxgr 2y ago
    Do you have details on what makes exFAT less safe than FAT32? To my understanding they should be pretty similar, at least. Obviously neither is journaling and might need the occasional fsck.
    - Kwpolska 2y ago
      From Wikipedia <https://en.wikipedia.org/wiki/ExFAT https://en.wikipedia.org/wiki/ExFAT>: > The standard exFAT implementation is not journaled and only uses a single file allocation table and free-space map. FAT file systems instead used alternating tables, as this allowed recovery of the file system if the media was ejected during a write (which occurs frequently in practice with removable media). ExFAT is also used by fake USB drives which claim to be much larger than they really are.
      - lxgr 2y ago
        > FAT file systems instead used alternating tables, as this allowed recovery of the file system if the media was ejected during a write (which occurs frequently in practice with removable media). This doesn't seem right to me (and the article also does not quote any source for this assertion). As far as I know, the secondary FAT is a leftover from days where block storage devices didn't have firmware-level bad block remapping, not really a consistency mechanism. It certainly doesn't prevent inconsistencies between files/directories and the FAT, and you still need an fsck-like process to clean these up that traverses the file system when mounting a non-clean ejected FAT. > ExFAT is also used by fake USB drives which claim to be much larger than they really are. USB drives are block devices, and if they maliciously trick the host into assuming larger size than they actually are, that's hardly the filesystem's fault, is it?
mikl 2y ago
Hence what I wrote above: > Would wish the industry could agree on using something more modern and reliable. There’s no techical reason why we can’t use NTFS on Macs or APFS on Windows, if the industry was willing work towards that goal together.
znpy 2y ago
Zfs should be installable on all three operating systems afaik though
- hobs 2y ago
  All of those options are mountable if you install third party tooling, that's not that interesting
- lxgr 2y ago
  Installable is nice, but preinstalled is the only thing that really matters for pluggable storage devices (USB drives, DSLRs that don't use MTP/PTP etc).
bitwize 2y ago
ZFS. There is never a good reason not to use ZFS. That's how it got its name -- "the last word in filesystems".
- lxgr 2y ago
  ZFS seems like massive overkill on resource-constrained embedded systems.
- josephg 2y ago
  But the last word in zfs is oracle. As I heard from an anonymous friend at Apple, macOS was weeks away from announcing an official transition to zfs and then oracle bought sun. Presumably, as a courtesy Apple asked oracle to confirm it was free to use zfs (since it was published under a permissive license). Oracle demanded money anyway. Apple blinked - not wanting to get sued by oracle. And the rest is history. A couple years later Apple wrote their own proprietary zfs like filesystem called APFS that has many similar features. And that has, to my knowledge, not been opensourced. (It does have very detailed documentation though. Holy cow - 180 pages. https://developer.apple.com/support/downloads/Apple-File-System-Reference.pdf https://developer.apple.com/support/downloads/Apple-File-Sys... )
  - lxgr 2y ago
    I think it’s unrealistic to think that Microsoft or any embedded device vendor would have ever implemented ZFS, regardless of the patent situation. macOS might have switched to something more modern a bit sooner than they did, but I wouldn’t be surprised if they hadn’t switched to APFS anyway after a while. Being able to independently drive your non-detachable-storage FS spec is a pretty big advantage as an OS vendor.
    - josephg 2y ago
      Well, according to my source, it would have actually happened if not for oracle. These decisions really come down to the people involved. I’m sure some people, given that choice, would never consider zfs. But some clearly would - and did. Using an opensource filesystem like zfs doesn’t mean you aren’t in charge of your own destiny. Apple has skilled systems engineers. They could easily have made custom extensions and changes to zfs if they saw fit.
mananaysiempre 2y ago
UDF should have been a viable alternative, but as I’ve said elsewhere it only works for disks smaller than 2T bytes with 512-byte sectors, and the Windows behaviour around it seems strange.

alt227 2y ago

exFAT is generally considered the more modern replacement.

robinsonb5 2y ago
But is still legally encumbered. FAT32 might have its limitations but it is at least small and simple enough to be implemented in a few K of boot code. That's the reason I still use it with FPGA projects.
Kwpolska 2y ago
ExFAT is a thing, but it’s less data-safe than NTFS (and than FAT32), and Linux distros might not ship drivers out-of-the-box.
- lxgr 2y ago
  Do you have details on what makes exFAT less safe than FAT32? To my understanding they should be pretty similar, at least. Obviously neither is journaling and might need the occasional fsck.
  - Kwpolska 2y ago
    From Wikipedia <https://en.wikipedia.org/wiki/ExFAT https://en.wikipedia.org/wiki/ExFAT>: > The standard exFAT implementation is not journaled and only uses a single file allocation table and free-space map. FAT file systems instead used alternating tables, as this allowed recovery of the file system if the media was ejected during a write (which occurs frequently in practice with removable media). ExFAT is also used by fake USB drives which claim to be much larger than they really are.
    - lxgr 2y ago
      > FAT file systems instead used alternating tables, as this allowed recovery of the file system if the media was ejected during a write (which occurs frequently in practice with removable media). This doesn't seem right to me (and the article also does not quote any source for this assertion). As far as I know, the secondary FAT is a leftover from days where block storage devices didn't have firmware-level bad block remapping, not really a consistency mechanism. It certainly doesn't prevent inconsistencies between files/directories and the FAT, and you still need an fsck-like process to clean these up that traverses the file system when mounting a non-clean ejected FAT. > ExFAT is also used by fake USB drives which claim to be much larger than they really are. USB drives are block devices, and if they maliciously trick the host into assuming larger size than they actually are, that's hardly the filesystem's fault, is it?

mikl 2y ago

Hence what I wrote above: > Would wish the industry could agree on using something more modern and reliable. There’s no techical reason why we can’t use NTFS on Macs or APFS on Windows, if the industry was willing work towards that goal together.

znpy 2y ago

Zfs should be installable on all three operating systems afaik though

hobs 2y ago
All of those options are mountable if you install third party tooling, that's not that interesting
lxgr 2y ago
Installable is nice, but preinstalled is the only thing that really matters for pluggable storage devices (USB drives, DSLRs that don't use MTP/PTP etc).

bitwize 2y ago

ZFS. There is never a good reason not to use ZFS. That's how it got its name -- "the last word in filesystems".

lxgr 2y ago
ZFS seems like massive overkill on resource-constrained embedded systems.
josephg 2y ago
But the last word in zfs is oracle. As I heard from an anonymous friend at Apple, macOS was weeks away from announcing an official transition to zfs and then oracle bought sun. Presumably, as a courtesy Apple asked oracle to confirm it was free to use zfs (since it was published under a permissive license). Oracle demanded money anyway. Apple blinked - not wanting to get sued by oracle. And the rest is history. A couple years later Apple wrote their own proprietary zfs like filesystem called APFS that has many similar features. And that has, to my knowledge, not been opensourced. (It does have very detailed documentation though. Holy cow - 180 pages. https://developer.apple.com/support/downloads/Apple-File-System-Reference.pdf https://developer.apple.com/support/downloads/Apple-File-Sys... )
- lxgr 2y ago
  I think it’s unrealistic to think that Microsoft or any embedded device vendor would have ever implemented ZFS, regardless of the patent situation. macOS might have switched to something more modern a bit sooner than they did, but I wouldn’t be surprised if they hadn’t switched to APFS anyway after a while. Being able to independently drive your non-detachable-storage FS spec is a pretty big advantage as an OS vendor.
  - josephg 2y ago
    Well, according to my source, it would have actually happened if not for oracle. These decisions really come down to the people involved. I’m sure some people, given that choice, would never consider zfs. But some clearly would - and did. Using an opensource filesystem like zfs doesn’t mean you aren’t in charge of your own destiny. Apple has skilled systems engineers. They could easily have made custom extensions and changes to zfs if they saw fit.

mananaysiempre 2y ago

UDF should have been a viable alternative, but as I’ve said elsewhere it only works for disks smaller than 2T bytes with 512-byte sectors, and the Windows behaviour around it seems strange.