How to mount read-write an ext4 partition on Windows?

Question

I want to use ext4 on my external HDD, but it must be cross-platform. (At least Linux, Win7 & WinXP).

Unfortunately, I haven't found any proper driver allowing Windows to WRITE to ext4. I've found Ext2Fsd, but it only reads ext4.

9. ext4 extent read-only, no size truncating and expanding support

More:

Supported Ext3/4 features:

• flexible inode size: > 128 bytes, up to block size
• dir_index: htree directory index
• filetype: extra file mode in dentry
• large_file: > 4G files supported
• sparse_super: super block backup in group descriptor
• uninit_bg: fast fsck and group checksum
• extent: reading, writing with no extending.
• journal: only support replay for internal journal

Unsupported Ext3/4 features:

• journal: log-based operations, external journal
• extent: size truncating & expanding, file deletion
• flex_bg: first metadata group
• EA (extended attributes), ACL support

Also, I have found a patch for Ext4Fsd v0.50 (here):

New: Matt Wu has made a new release 0.50 at ext2fsd.com. Ext2fsd-0.48-bb8-signed Support for ext4 extents and fix for BSOD on Windows 7.

I don't think it will be safe. Also I've read some words about writing ext4 in Windows could cause data loss on the disk...

What is the External HDD used for? - First, it will store backups, then family movies, pictures. Some music, and etc. It will be connected to a Raspberry Pi, if I finally receive it. It won't really move, just when it is used to migrate computer's data to a new one. The largest files it will store are Clonezilla disk images (I don't know, if they will be large files or not).

Can someone provide a solution for this problem? Or is there NO important enough difference between ext4 and ext3, and I should use ext3? - (If yes, then can I use Ext2Fsd for that ext3 mount?)

Thank you!

Solution 1

I would use NTFS instead. It can easily be read/written to by Linux, Windows and OS X (among others).

Considering the intended use and the fact that it is an external drive, I see no reason why you should go through the hassle that using ext4 will be.

If this were your primary hard drive, perhaps the advantages of ext4 (briefly, less drive fragmentation and slightly improved performance, for more information see here) would be worthwhile. I doubt you will even notice a difference on an external USB drive. The bottleneck will be the rate of data transfer over the USB cable.

For most users, the only obvious benefit of ext4 over NTFS is that ext4 allows file names with special characters (? & % etc). Such file names, however, are both a bad idea and of no particular interest to you.

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EDIT: In answer to B. Roland's question about defragmenting, yes, there are two ways I know of to defragment an NTFS drive under linux. One is an open source tool called shake. I haven't used it but it seems to work. The other is simply copying all data from the external drive, deleting everything from the drive and then copying everything back. Finally, since your drive will also be accessed under windows you can use the windows defragmenter.

I think, however, that you are attaching way too much importance to drive defragmentation. Have a look here for a simple explanation of fragmentation. Briefly, a fragmented drive is one where the files on the drive are not stored in contiguous blocks but spread out across the drive. This is usually caused by changing a file's size after it has been written. So, say you save a 1 MB file on your drive. You then modify the file and its size goes up to 20 MB. If there is not enough free space at the position where the file was created, this extra data will be written to a different part of the hard drive. In other words, the file will be fragmented.

This kind of thing is not likely to occur very often in a drive used for storing "backups, then family movies, pictures. Some music, and etc". Most of these files will never change in size, and therefore, will never fragment the drive.

In addition, even if your drive is fragmented, you don't really care. Fragmentation can be a problem for system drives where you can have many I/O operations per second. In those cases you can notice a decrease in drive performance. As I said before, on an external drive I don't think you will be able to detect this, even if it does happen.

So, in conclusion, you almost certainly will not need to defragment an NTFS formatted external HDD. However, if you really want to, you can do it both in Linux and in Windows.

Solution 2

Paragon software offers ExtFS for Windows 2.0 for free for personal use. It allows to read and write ext2 ext3 and ext4 from all Windows OS

http://www.paragon-software.com/home/extfs-windows/

It appears to be somewhat similar to Linux Reader from Diskinternals, that can mount all ext, HFS and ReiserFS too, but read-only.

http://www.diskinternals.com/linux-reader/

Solution 3

If you want to SOME of the features of EXT4, you can use them using tune2fs to add the features to an EXT3 partition. The latest Ext2FSD release notes should list which features you can enable. You may want to read the tune2fs man page, there are some hints on how to handle writing to the filesystem in the header that can be beneficial to set for a backup drive that requires reliability, or to set to the other extreme for a drive containing non-critical files that require fast access and fast read-write times

You don't really need extended attributes and ACLs, and depending on your Linux setup they may not even be active to begin with. Incompatibilities between Windows and Linux on permissions makes it ill-advised to use this feature cross platform, even if supported.

Comments

[terdon]

Have a look at this page. I don't think that using ext4 for an external hard drive is worth the headache. Why do you not want NTFS or FAT32? Do you need support for huge files?

[antivirtel]

Thank you for the link. I forgot add the situation, and aim of the External HDD. Added to the question now. Otherwise, what size do you mean in large files?

[Keltari]

I agree with terdon. Make the drive NTFS and it will be compatible with most OSs out there.

[terdon]

One of the many limitations of FAT32 is that it cannot deal with files larger than 4GB. NTFS (16 EB) and ext4 (16 TB) do not have that limitation.

[Reticulated Spline]

Neither the linked duplicate nor the accepted answer actually answer this question.

[Keltari]

I completely agree. NTFS (and FAT32) are simply the most portable file systems out there.

[antivirtel]

Will the NTFS worth data fragmentation problem? Ext4 has no fragmentation. Otherwise it has USB 3.0 connector, so it is much faster than a normal USB 2.0. Portability is secondary. It is a WesternDigital My Book Essential (1TB)

[terdon]

@B.Roland IMHO, yes. Granted NTFS will have more fragmentation but, again, this should not be a serious problem on an external, non system drive. I really think using ext4 is simply not worth the effort. I very much doubt that you will see any improvement at all. It may be there, but it will probably not even be detectable unless you run benchmarks. I really doubt you will notice any difference as a user.

[antivirtel]

Oh, ok @terdon, if you add something about how to defragment NTFS on a Linux, I'll accept your answer. (eg. linuxquestions.org/questions/linux-newbie-8/…)

[eichoa3I]

I disagree that it can be easily read/written by all. There's an overhead to ntfs-3g on *nix.

[terdon]

@jhstuckey I never claimed there was no overhead. Still NTFS is the best filesystem that can be easily read/written by the greatest number of OSs. By easily I mean easily for the user not necessarily the kernel.

[phuclv]

In fact NTFS does support POSIX filenames but default it will be disabled on windows because of compatibility reasons

[Rajib]

Is Paragon adware/malware free and completely safe? Have you used it yourself?

[phuclv]

en.wikipedia.org/wiki/NTFS "In Posix namespace, any UTF-16 code unit (case sensitive) except U+0000 (NUL) and / (slash)." support.microsoft.com/kb/100625

[monnef]

The Paragon software is not working for me (ext4 created from Ubuntu 14.04 LTS), on Windows 8 got only read access. When creating a file it crashes with a message informing me that the new file is too big - empty txt file.

[Mike de Klerk]

I did not expect that the (accepted) answer to the question "How to mount read-write an ext4 partition on Windows?" would be to use NTFS instead when clicking on this link from Google. I am in a situation where it is no option to use NTFS, it is ext4. I want to know how to read/write ext4 from windows (thats how I got to this URI). I am not searching for good advice. Though I can imagine this may be the answer to the OPs question.

[terdon]

@MikedeKlerk in the case of the person asking the question, using NTFS was the better solution. Have a look at the other answers for different solutions.

[Gunslinger]

I went through the pain to download, install and register it. Theyr require an email to send serial to and I used a "10 minute email". Probably spam supported.

[Gunslinger]

But it did manage to mount an ext4 partition to my windowns 10 read/write.

[Archibald]

Unfortunately on win 7 when writing over files on ext4 partition it corrupts them.

[Aaron Franke]

Paragon isn't working for me: superuser.com/questions/1189512/…

[phuclv]

NTFS supports POSIX namespace so it can store special characters like *?:... in file names without problem. It's just the limitation of win32 namespace

[Robert Wm Ruedisueli]

First, that was not the question. Second, NTFS implements permissions differently than Linux. It runs inefficiently on Linux according to tests by android developers, and it does not support many features such as extended attributes and filetype storage.

[terdon]

@RobertWmRuedisueli perhaps, but as you can see it was the answer. The OP just wanted to have an external drive that could be used in both Linux and Windows. The best approach for that is ntfs and not ext. Neither efficiency nor extended features are relevant in this particular case.

[Robert Wm Ruedisueli]

@terdon I agree on that front. I wish that there was better support for EXT4, F2FS and BTFS in Windows. This is especially important to Android developers and modders, as Android devices and VMs commonly use these filesystems for their Data partitions.

[Damn Vegetables]

On Raspberry Pi, NTFS performance is very low. For the same disk, NTFS's write speed was about 30MB/s, whereas EXT4's write speed was about 100MB/s.

[Shodan]

Paragon is no longer working, there is no download link, there is no buy link, they actually ask you to "call their sales team" so that's a big nope. Looks like the only option is going to be linux-reader or windows WSL2

[Shodan]

"Just use NTFS" is a really bad answer to "How to mount read-write an ext4 partition on Windows?"

[terdon]

@shodan OK. Please downvote instead of commenting then.

[FHannes]

NTFS is indeed better supported on Linux than ext4 is on Windows. But that says something about the commitment of the Linux community, not about the quality of the filesystem. This answer is definitely not a good answer to this question. The question may state it is needed to transfer files between OS's, but it explicitly asks to use ext4.

[terdon]

@FHannes please downvote instead of commenting. That's what the votes are for. This is not a discussion forum, and I am frankly quite tired of receiving comments a full decade after posting an answer that actually solved the problem the OP was having (as you can see, the answer was accepted). You are, of course, free to disagree, but please do so by voting instead of adding yet more noise. At the very least, take the time to read the existing comments and see if you actually have anything to add or if you are repeating what others have said in the past ten years.