A Btrfs File-System Kernel Driver For Windows

[drSeehas]

No. It also doesn't support deduplication. ...

So it is a comparison of apples and oranges.

[liam]

So it is a comparison of apples and oranges.

If write through deduplication is the defining feature of a filesystem..... well, no, not even then is it "apples and oranges".
The feature MOST zfs advocates would push as its signature benefit would be data integrity. It was in that sense that I advocated for ReFs.
If your goal was to find the features of zfs that ReFs doesn't support you could've mentioned that to start and I wouldn't have b bothered replying.

[SystemCrasher]

Lol, now Windows can finally get more or less adequate filesystem, and one can use btrfs on e.g. removable drives.

[nasyt]

What the hell is the usecase of BTRFS on Windows? The On-disk format of NTFS supports one yottabyte. BTRFS just supports 16 Exabyte. Thats not much.

And Storage Spaces will fill the gap.

[maharmstone]

I've just released a new version of the driver which contains a load of bug fixes - if anybody's been having problems, could you try this please? https://github.com/maharmstone/btrfs

[Hi-Angel]

What the hell is the usecase of BTRFS on Windows? The On-disk format of NTFS supports one yottabyte. BTRFS just supports 16 Exabyte. Thats not much.

And Storage Spaces will fill the gap.

Where did you find one yottabyte? NTFS format supports 16 Exabyte maximum size as well.

[DrYak]

How do I format an USB stick or a SD card on Windows (7) with UDF?
NTFS, FAT32 and exFAT are the only options offered.

My proposition of UDF is for when you want cross-OS portability of the data.
That would pre-suppose that you have access to several other OSes, the majjority of which is able to do the formatting.
(So just format the stick using the non-windows OS with which you want to inter-operate with)

If you're only ever going to use a stick in a Windows 7 machine, exFAT (as the "official" FS for Microsoft) would make more sense. (Though UDF is also tested a lot given its use on optical media, including read-only, eraseable and packet writing).

If you still want to format it as UDF *and* only have access to a Windows 7 box, I would recommend, in order:

(The first solutions are basically "use linux anyway". It's a bit lame but that's what i'm most fluent with)

Solution 1:
Get a boot disk. System Rescue CD is a very nice candidate: it has ton of tools that come handy.
Then you can format your stick with that (and also use the disk if you need to use to rescue a machine)

Solution 2:
Use a Linux install on a VM like virtual box, and forward the USB stick (either the USB device itself, or the block device) to the VM and format it from there.

(I don't have as much experience with windows so the next solutions are approximative)

Solution 3:
according to the stackexchange cited elsewhere:
`format x: /fs:UDF` (without the quickformat option)
I haven't tested this my self.
Pay attention to create the special "boot region of the UDF contains a partition table pointing back at itself" structure mentionned in the Linux articles I mention (and handled by the Perl scripts) using you favorite windows disk partitionning tool (and disabling its warnings about overlapping partitions).

Solution 4:
Check your DVD burning software, and its low-level packet writing drivers and tools. For older versions of Windows and DOS that don't support UDF, that's the route to add support for UDF, and maybe the UDF support software offers formatting possibility ?
(This will very likely NOT generate the necessary partition table)

Solution 5:
Generate an image with any UDF-generating tools (your favourite DVD burning software should be able to write an .ISO file. Pay attention to have at least UDF version 1.5 selected and no ISO9660).
Then RawWrite should be able to write your image on the device.
(you might still need to have the proper partition table, though. So using a combo of your favorite partitioning software, rawwrite in read mode and your favorite hexeditor to combine it into the image might be necessary)
I have regularily used this tool when I needed to write a partition in a format not supported by windows, mostly for EXTn formatted linux USB boot sticks, when stuck on a windows machine. Rawwrite is a nice Windows substitute for Linux' `dd`

Note that none of the windows solution (3 to 5) are completely straight-forward compared to the Linux ones (just download the perl script and run it).

What the hell is the usecase of BTRFS on Windows?

When you need a format that is cross portable accross OSes, and has additionnal features like copy-on-write, checksumming, transparent compression, cheap snapshotting, support for posix permissions.

(Though UDF is also cross-os and at least is log structured).

[drSeehas]

...
If you still want to format it as UDF *and* only have access to a Windows 7 box, I would recommend, in order:
...
Solution 3:
according to the stackexchange cited elsewhere:
`format x: /fs:UDF` (without the quickformat option) ...

Thank you, BUT
Why 5 solutions?
Shouldn't the command line
FORMAT x: /FS:UDF /R:1.50 or 2.01
be sufficient?

... Pay attention to create the special "boot region of the UDF contains a partition table pointing back at itself" structure mentionned in the Linux articles I mention (and handled by the Perl scripts) using you favorite windows disk partitionning tool (and disabling its warnings about overlapping partitions). ...

Which Linux articles are you refering to?

One question remaining:
What partition type/ID for UDF?

[DrYak]

Which Linux articles are you refering to?

Ooops. Sorry, that's entirely my fault. Usually I quote these source when I speak about UDF on flash media:

• filesystems for portable disks by Pieter Wullie - initial research (NOTE: today the server seems not responding. Either use your favorite caching tool or retry in a few days)
• UDF Harddisk code by Pieter Wullie - script based on the above (NOTE: server down, in the meantime there's a copy of it there)
• Sharing a Hard/Flash Drive across Windows, OS X, and Linux with UDF - A very detailed (and long) explanation by JElchison
• Format-UDF code by JElchison - up-to-date tool

At least check the last two.

Thank you, BUT
Why 5 solutions?

I'm partial to multiple solutions.
Also I'm not a hardcore windows user, so I would like to throw some alternative solution in case another doesn't work.

Shouldn't the command line
FORMAT x: /FS:UDF /R:1.50 or 2.01
be sufficient?

As explained in the articles I'm citing above:
Saddly, it's not necessarly enough.
This will get cross-compatible with Linux, but not Mac OS X.
It all boils down to how each OS will detect the partition.

Linux: has a very robust plug-n-play system and will happily use whichever you throw at it.

Windows: *only* detect UDF when it is on partitions (you can't format a whole disk UDF, the X: letter must be a valid partititon)

Mac OS X: exact opposite, *only* detects UDF when it's a bare drive (like a DVD).

Now there is a small trick:
UDF on purpose leaves a few KiB at the beginning untouched (that's mainly used to put bootloaders in there like on bootable installation DVDs).
So you can format the whole drive, and then use the empty bootloader space to put a partition table with a partition entry that points back to the whole disk.
(Or feel free to do it in ther other order around if your formatter leaves the bootloader space untouched).

So now Mac OS X is happy (the UDF partition uses the whole disk), AND Windows is happy too (there is a partition table pointing to said whole-disk partition).
Linux is happy no matter what anyway.

(This boot loader space might also be another source of problems: some formatters won't touch it by design. But if you're re-formatting a stick that was previously formatted as FAT32, there might be enough left-overs in said space that windows might detect and attempt to use the wrong type.
Linux doesn't give a damn, there's a "-t" option of mount exactly for that purpose: to be able to force a specific type, when a partition holds several.
But Windows might choke on it).

One question remaining:
What partition type/ID for UDF?

On my USB stick, formatted back at the time with Pieter Wullie's code, the partition is marked as a 'b' (FAT32).
The newer code by JElchisson does the same too.

But in my experience, Windows has never paid any attention to the partition type. Win XP regularily wanted to reformat ext3 partition which were clearly marked as type Linux. As long the data is recognized as some format supported (FAT32, exFAT, NTFS, exFAT, UDF, ISO, etc.) windows is happy.

Mac OS X doesn't pay attention to the partition table (as explained above it goes straight for the whole disk when looking for UDF).

Linux has a robust scheme of detection.

(My brother's Nintendo New 3DS was the only device to choke on a wrong FS type entry in the partition table).

[drSeehas]

...

• Sharing a Hard/Flash Drive across Windows, OS X, and Linux with UDF - A very detailed (and long) explanation by JElchison
• Format-UDF code by JElchison - up-to-date tool

... As explained in the articles I'm citing above:
Saddly, it's not necessarly enough.
This will get cross-compatible with Linux, but not Mac OS X.
It all boils down to how each OS will detect the partition.
...
Windows: *only* detect UDF when it is on partitions (you can't format a whole disk UDF, the X: letter must be a valid partititon)

Thank you.

But I am confused:
On https://j0nam1el.wordpress.com/2015/...inux-with-udf/ and https://github.com/JElchison/format-udf I read

... Windows does not support hard disks without a partition table. This is strange because Windows does not apply the same limitation to flash drives.

When I use a "flash drive" e.g. SD card, I don"t need a partition table for Windows and I can format the whole SD card as a "super floppy"?
So I have no problem with Windows and OS X.