Aug 202012

exFATMost of us will know the Microsoft FAT16 and FAT32 filesystems that have been in use most prominently with Windows 9x/Me operating systems, and if you’re an old guy you might also know FAT12 used for floppy disks. Today, the former two are still widely used to exchange data between heterogenous operating systems (Windows/Unix/Linux/MacOS/BSD..) and also to exchange data between computers and media devices such as digital cameras, music players, cellphones etc. But the formatters of Windows usually don’t allow the formatting of storage devices larger than 32GB with FAT32 (although it’s possible and also readable in Windows). Also, FAT32 has harsh limitations in the regards of maximum file size (4GB) and access control lists (none).

Hence, FAT64, or “exFAT”. Why is this even important you might ask? Because the file system is in the specification of SDXC and MSXC flash cards used for cameras and camcorders, as well as many other devices like set-top boxes. Not that you couldn’t format it with something else on Linux, but spec is spec.

So I tried to get exFAT to work on Windows XP Professional x64 Edition using Microsofts official update [KB955704], which is available not only for XP x64, but also regular XP, Server 2003 and Server 2003 for IA64/Itanium. I first tried it with a 1GB flash card, a Sony MemoryStick actually, and with a 120GB USB HDD, which showed a little problem appearing with NTFS format options when this update is installed. Also, the announced ACL support seems to just not be there with this update. There are no security-related options at all.. See a series of screenshots with exFAT in use:

So there you can see, that the NTFS option disappears for a removable USB HDD larger than 32GB as soon as exFAT is installed. Previously, FAT32 wouldn’t be allowed, so Microsoft simply had to make NTFS available for such a drive as the single remaining FS. Now that we’ve got exFAT, NTFS is forbidden, even on the console with format.exe! Well, almost forbidden. They haven’t thought it all the way through though, so you can still do an NTFS format in disk management in the administrative tools. There, you’ll never see any exFAT option anyway, it’s simply not implemented. Talk about consistency, eh? For large fixed disks, as also shown in the screenshots, both NTFS and exFAT are now available.

Now the other problem is that while files >4GB now work perfectly fine due to 64-Bit address space (which is very good!), the announced ACL support is obviously not implemented here. You can’t set an owner, you can’t set read/write/execute permissions or anything. In that case it behaves just like any FAT on Windows would, which is a bit disappointing. It might be, that if you connect an exFAT volume with ACLs to such a machine, the exFAT kernel driver would just silently ignore all kinds of implemented ACLs, like a cracked driver.

At least, with this driver you will get support for all new flash card formats, so if you want to go on with XP or XP x64, you can still use your fancy new cameras SDXC or MSXC card without having to play tricks on it and format it with FAT32 outside of Windows. That alone is nice enough I have to admit! And it’s even an official driver from Microsoft, not some Panasonic or Matsushita 3rd party driver like with the UDF 2.5 filesystem for Blu-Rays!

I also got this to work on CentOS Linux now, using the fuse system (user-space fs driver). To build fuse-exFAT, you need GCC, scons, fuse-devel/libfuse-dev and subversion. You can get the driver and utility sourcecode [here], along with some binaries for a few systems .

CC BY-NC-SA 4.0 exFAT on Windows XP (x64) by The GAT at is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

  9 Responses to “exFAT on Windows XP (x64)”

  1. Interesting to see that 11TB volume, but have you tried format to exFAT under 32-bit XP with large volumes (2TB+)? With NTFS I can format 2TB+ volumes, but it looks like 32-bit XP is limited to 2TB exFAT volumes (or I’m doing something wrong because formatting fails every time). I even tried formatting in 64-bit Win7 and transfer that drive to XP machine (using Paragon’s GPT loader), if exFAT file system is not detected, if NTFS it works ok.

    It’s like in old days, 6GB HD -> 3*2GB partitions with FAT16 (DOS 6.22), nowadays 6TB drive -> 3*2TB exFAT (WinXP 32-bit) partitions. :D

    And thanks for good articles, I did find a lot of interesting stuff to read for a XP-guy like me!

    • Good morning KK,

      Reassuring to see that there are still people who can profit from me fooling around with XP & XP x64! In recent years, a lot of hate has been blowing my way when asking questions about XP elsewhere on the web… :|

      As for exFAT: I haven’t tried formatting >2TiB volumes on WinXP 32-bit with it yet. Frankly, I haven’t actually done the formatting on XP x64 either (the 11TiB volume had a lot of live data on it, so I couldn’t just wipe it, as that would have caused an extensive downtime). So it might be impossible on both operating systems. I just assumed that if it’s listed in the formatter, it should work. Heh, maybe not.

      I’m afraid I can’t help you with that, as I can’t really test this at the moment. I don’t have Paragons GPT loader either (There is no trial version?!).

      Ah, I have to thank you for mentioning Paragons’ GPT software for XP 32-bit though! I wasn’t aware of Paragon providing such a product. Nice to know we can use GPT data volumes on XP 32-bit now as well! :)

      • Thanks for answering, as you said, nowadays it’s hard to get answers about WinXP. To be exact, good answers, first reply is always “WinXP is obsolete, install Win7/8/10… ” :D

        About exFAT: Ok, so this remains as a mystery. It looks like 32-bit Vista is also unable to format >2TiB exFAT partitions (I found this info from Google). So it can problem in all 32-bit Windows or just all Windows versions before Win7 (x64?). Looks like more testing is needed. :)

        About Paragon: Yes, GPT volumes works ok in 32-bit WinXP. :) I think there is no trial version from Paragon, but it was offered as a free download with some HDDs (Hitachi at least). So it might be still available, but many companies have removed support for XP so it can be hard to find. However, for WinXP 32-bit users there are also programs called “3TiB Unlocker” from motherboard manufacturers (Asus, Asrock, Gigabyte) which split >2TiB drives to 2TiB parts. For example 3TiB drive shows as 2TiB and 1TiB drives. Not as good as Paragon GPT Loader because those drives works only with that software (to be exact, first 2TiB works without that software), with Paragon drives can be swapped between different operating systems.

        • Hey KK,

          I can see how using the GPT loader is preferable. Actually, I know that “splitting trick” from my old 3ware 9650SE-8LPML RAID controller, although it could do it at the firmware level (so it’s portable across systems, doesn’t need software). It was known as “LUN carving”, supporting a total of 8 SCSI-style LUNs for a maximum of 8×2TiB=16TiB capacity.

          I used that with XP 32-bit back in the days, for a 5.45TiB array (2+2+1.45). Together with Windows’ dynamic volumes, i stitched everything back together into one spanned volume, and formatted it as a single NTFS file system. It worked, but it’s still kinda makeshift, so I’m using GPT for my new array now. ;)

          I also heard of those weird software solutions, mostly from Western Digital as far as I can remember. I never wanted to touch that stuff in the first place…

          @WinXP/exFAT: Funny thing is, by now it’s easier to get proper answers when you ask about Windows 2000 instead of XP. :roll: I’m not actually using exFAT at the moment however. My current camera – a Nikon V1 – also doesn’t use it, still the same old FAT32. Maybe I’ll have to use it with the next one.

  2. Funny bit about that ACL issue. It makes me think of a question: Do people even bother writing (read: patching) cracked NTFS drivers?

    I mean, just reboot (including bootable CD versions) into Linux or another copy of Windows (or even ReactOS) and you can do whatever you want. It’s not like it’s encrypted or something. Merely obfuscated and proprietary (and patented). Good thing that someone’s figured it out! ;)

    • This is also true for any other file system though. If I just boot Knoppix and become root, I can mount almost any file system and it will no longer provide any security through its POSIX permissions or ACLs. No file system can protect from physical attacks. For that you’d use Luks/dm-crypt or TrueCrypt and the like. :)

      It’s strange though, that ACLs have just been stripped from or never implemented in the driver even though exFAT was supposed to have those. I guess they thought it was pointless anyway, if we’re just gonna use it for camera and cellphone flash memory cards.

  3. Thanks a lot for taking your time and write such a nice and informative article. This kind of information is really hard to find!!

  4. […] [exFAT on XP x64] (Article), [exFAT download] (XP 32/64-Bit) […]

  5. Very nice writeup. Loved the pics, extremely helpful. Made my mind to install the KB955704 update now. Hopefully performance for many small files on a usb stick will improve dramatically.

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