3 ms·

So, why didn't XFS "win" out over ReiserFS, ext3/4, btrfs, or whatever else is being pushed nowadays?

Maakuth 12y ago
Btrfs is still very new as a filesystem. There's little evidence that it can hold up in production use. It is similar to ZFS, which is the filesystem of choice for many large deployments. Unfortunately ZFS can't be distributed with Linux because of license mismatch. Ext3/4 are of previous generation of filesystems, their performance on very large volumes is not acceptable. And you don't want your production system to be down because of boot-time fsck for hours. ReiserFS had some promise years ago, but the project leader is in prison and nobody has picked up the effort. I don't think it's possible for it to close the gap to other filesystems even if Mr. Reiser returns to develop it after his sentence.
- ryao 12y ago
  I am not a lawyer, but I have yet to speak to a lawyer who claimed you could not distribute a Linux kernel module under an "incompatible" license when the said module is not considered a derived work of GPL software. Any Linux port of ZFS is a derived work of OpenSolaris (in the legal sense), such that you can distribute ZFS with Linux as long as it is a separate kernel module. There are plenty of companies doing this. I have spoken to lawyers regarding this and I have yet to meet a lawyer who disagrees when asked if the GPL applies to a Linux ZFS kernel module. To be honest, I did encounter one attorney who thought that certain forms of advertising might be able to trigger the derived works clause, but he considered it to be an avoidable problem and his opinion was an outlier.
  - Maakuth 12y ago
    To my understanding this is quite an open issue, and it's hard to find a company that would want to risk it in court. ZFS on Linux project currently distributes the modules as source, and they are built for particular kernel locally in any machine that needs the modules. This is the same approach as GPU vendors do with their closed source graphics drivers.
rockdoe 12y ago
I would think it did? ext4 is the most deployed when you don't need extra features, because it's very stable, seamless upgrading from ext3, universaly GRUB support, and has little surprises and is actually pretty fast. ReiserFS is mostly dead, btrfs isn't even really stable yet and is slower. I wouldn't be surprised if XFS was the second most deployed filesystem after ext4. Where it's really losing is to the "block layering violations" of btrfs. Being able to manage storage pools at the filesystem level like ZFS is a major feature advantage.
rodgerd 12y ago
Dave Chinner works for Red Hat, and XFS is the default FS on the most popular commercial Linux distro. Seems like winning. If you mean, "why didn't it win earlier?" it's probably a combination of ext3 being good enough (particularly when multi-spindle, large partition environments were less common for Linux users), Reiser3 doing a great PR job (pity about the crappy filesystem...), and ext3 having better data integrity because Ted T'so didn't understand how his filesystem implementation worked (he fixed that with ext4).
deleted 12y ago
[deleted]

Btrfs is still very new as a filesystem. There's little evidence that it can hold up in production use. It is similar to ZFS, which is the filesystem of choice for many large deployments. Unfortunately ZFS can't be distributed with Linux because of license mismatch. Ext3/4 are of previous generation of filesystems, their performance on very large volumes is not acceptable. And you don't want your production system to be down because of boot-time fsck for hours. ReiserFS had some promise years ago, but the project leader is in prison and nobody has picked up the effort. I don't think it's possible for it to close the gap to other filesystems even if Mr. Reiser returns to develop it after his sentence.

ryao 12y ago
I am not a lawyer, but I have yet to speak to a lawyer who claimed you could not distribute a Linux kernel module under an "incompatible" license when the said module is not considered a derived work of GPL software. Any Linux port of ZFS is a derived work of OpenSolaris (in the legal sense), such that you can distribute ZFS with Linux as long as it is a separate kernel module. There are plenty of companies doing this. I have spoken to lawyers regarding this and I have yet to meet a lawyer who disagrees when asked if the GPL applies to a Linux ZFS kernel module. To be honest, I did encounter one attorney who thought that certain forms of advertising might be able to trigger the derived works clause, but he considered it to be an avoidable problem and his opinion was an outlier.
- Maakuth 12y ago
  To my understanding this is quite an open issue, and it's hard to find a company that would want to risk it in court. ZFS on Linux project currently distributes the modules as source, and they are built for particular kernel locally in any machine that needs the modules. This is the same approach as GPU vendors do with their closed source graphics drivers.

rockdoe 12y ago

I would think it did? ext4 is the most deployed when you don't need extra features, because it's very stable, seamless upgrading from ext3, universaly GRUB support, and has little surprises and is actually pretty fast. ReiserFS is mostly dead, btrfs isn't even really stable yet and is slower. I wouldn't be surprised if XFS was the second most deployed filesystem after ext4. Where it's really losing is to the "block layering violations" of btrfs. Being able to manage storage pools at the filesystem level like ZFS is a major feature advantage.

rodgerd 12y ago

Dave Chinner works for Red Hat, and XFS is the default FS on the most popular commercial Linux distro. Seems like winning. If you mean, "why didn't it win earlier?" it's probably a combination of ext3 being good enough (particularly when multi-spindle, large partition environments were less common for Linux users), Reiser3 doing a great PR job (pity about the crappy filesystem...), and ext3 having better data integrity because Ted T'so didn't understand how his filesystem implementation worked (he fixed that with ext4).

deleted 12y ago

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