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Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

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Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#51

Post by WastingMyTime89 »

waynesonfire wrote: post #38
WastingMyTime89 wrote: post #37

Earlier quoted context omitted.

ZFS will never be mainlined so it’s beyond useless.

ZFS is widely used by many users and organizations. Just because it is not currently included in the Linux kernel does not mean that it is useless. There is ongoing work to integrate ZFS into the Linux kernel, and in the meantime, many users continue to find value in using ZFS on their systems. As an alternative, you could try using FreeBSD, which includes ZFS as part of the kernel. This can make it easier to take ad…

Enlighten me on how a filesystem with an incompatible license is ever going to be mainlined. Having to use an out-of-tree patchset is an immediate no as far as I’m concerned. I also have no intention of switching to an hobbyist operating system, thank you.

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#52

Post by dale_glass »

dekhn wrote: post #27
dale_glass wrote: post #19

But is the RAID handling remotely sane yet? See https://arstechnica.com/gadgets/2021/09/examining-btrfs-linu... It has gems such as: * It won't boot on a degraded array by default, requiring manual action to mount it * It won't complain if one of the disks is stale * It won't resilver automatically if a disk is re-added to the array I think the first is the killer. RAID is a High Availability measure. Your system is…

Many folks I know who manage storage don't make the boot volume RAID (redundant)- instead, it's some rapidly duplicatable thing like an NMVE flash containing the root filesystem, and there's a replacement handy. Then you can bring up and bring the full power of userspace to bear on the RAID repair.

That seems like a very hacky way to accomplish something that should just work. I mean, it's better than nothing, but it seems far from ideal.

If it's your own personal box, and you're okay with that fiddling, fine. But if people are supposed to get work done while the admin gets a new disk, it's not great.

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#53

Post by skyyler »

WastingMyTime89 wrote: post #51
waynesonfire wrote: post #38

Earlier quoted context omitted.

ZFS is widely used by many users and organizations. Just because it is not currently included in the Linux kernel does not mean that it is useless. There is ongoing work to integrate ZFS into the Linux kernel, and in the meantime, many users continue to find value in using ZFS on their systems. As an alternative, you could try using FreeBSD, which includes ZFS as part of the kernel. This can make it easier to take ad…

Enlighten me on how a filesystem with an incompatible license is ever going to be mainlined. Having to use an out-of-tree patchset is an immediate no as far as I’m concerned. I also have no intention of switching to an hobbyist operating system, thank you.

You're already using a hobbyist operating system... Your horse isn't as high as you think.

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#54

Post by doublepg23 »

viraptor wrote: post #14
candiddevmike wrote: post #8

Maybe I'm just cynical but I think the ship has sailed for BTRFS RAID 5/6. It's now part of the global mindshare that BTRFS RAID 5/6 == data loss, no one wants to be the guinea pig that proves it works. Better to direct resources towards bcachefs or ZFS IMO.

Ideally we'd be working based on actual information rather than global mindshare. There will be guinea pigs to test it. There are already quite a few people running it despite the warnings. As much as I want to see a wide use of bcachefs, it's still years away. As someone who actually wants to store data - why would you direct resources to bcachefs which is known experimental, rather than btrfs which plainly document…

Is bcachefs years away? My understanding is the critical chain of code is pretty well tested - bcache.

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#55

Post by chasil »

DominoTree wrote: post #35

I've never lost data with btrfs, but I have purposefully avoided anything other than basic disk configurations. I use it on my workstations because it's the default in Fedora these days and haven't had any complaints. On the flip-side, I've done some of the most horrible things possible and screwed up my 30-disk ZFS array a number of times and I've never lost data. I doubt btrfs could recover from anything I've done…

Btrfs is able to do one important thing that ZFS cannot: defragment.

I see XFS as the performance leader (appears on TPC.org the most often that I can see), btrfs as the fullest featured, and ZFS with the strongest reliability.

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#56

Post by dale_glass »

chomp wrote: post #47
klysm wrote: post #24

Earlier quoted context omitted.

> * It won't boot on a degraded array by default, requiring manual action to mount it That by itself is a complete deal breaker.

Why? Are you in a position where you can’t modify grub or fstab?

Because RAID is a High Availability technology.

It's not a backup. It doesn't protect against mistakes, bugs, or the server failing in some other way. What it's good for is for ensuring that work keeps happening if a disk fails. And disk failures happen to be fairly frequent, since spinning rust is a rather delicate technology.

If somebody has to connect to the machine and fiddle with it by hand it means that the system has been down, possibly for hours, when that was the exact thing you were trying to prevent by setting up RAID on it.

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#57

Post by chasil »

WastingMyTime89 wrote: post #51
waynesonfire wrote: post #38

Earlier quoted context omitted.

ZFS is widely used by many users and organizations. Just because it is not currently included in the Linux kernel does not mean that it is useless. There is ongoing work to integrate ZFS into the Linux kernel, and in the meantime, many users continue to find value in using ZFS on their systems. As an alternative, you could try using FreeBSD, which includes ZFS as part of the kernel. This can make it easier to take ad…

Enlighten me on how a filesystem with an incompatible license is ever going to be mainlined. Having to use an out-of-tree patchset is an immediate no as far as I’m concerned. I also have no intention of switching to an hobbyist operating system, thank you.

I recently tried out the Ubuntu native ZFS installation.

I was surprised to see that it taints the kernel when I checked the demsg.

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#58

Post by viraptor »

dale_glass wrote: post #45
_kdave wrote: post #36

Earlier quoted context omitted.

> It won't boot on a degraded array by default, requiring manual action to mount it If you want it to behave like that then add 'degraded' to fstab. That a device is missing can have unknown reasons, the user should know better and resolve it or allow such boot. It's not automatic as there's no way to inform the user that it's degraded state.

I don't quite understand the use case here. If I'm setting up RAID it's because I want the system to stay up. That's the only purpose for it. If a device goes missing for "unknown reasons", then the machine should still work, and I'll figure out what happened when monitoring pokes me and says RAID is degraded.

The use case is: Enough drives failed that your raid is degraded. Any more data you write is not replicated and it may be due to software/hardware issue that will kill more drives soon.

It's up to you to choose at that point - is availability more important for you (add degraded to fstab), or data consistency (deal with the array first).

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#59

Post by lmm »

walrus01 wrote: post #5

I wonder how this compares to just using mdadm block device level raid5 or raid6. And then a normal filesystem on top.

Having used ZFS and mdadm+conventional filesystem, the vertical integration is a lot nicer and smoother to work with. You don't waste time scrubbing empty space. If there's corruption then you know specifically what files were affected, effortlessly.

Re: Btrfs in Linux 6.2 brings performance improvements, better RAID 5/6 reliability

#60

Post by coptun »

candiddevmike wrote: post #8

Maybe I'm just cynical but I think the ship has sailed for BTRFS RAID 5/6. It's now part of the global mindshare that BTRFS RAID 5/6 == data loss, no one wants to be the guinea pig that proves it works. Better to direct resources towards bcachefs or ZFS IMO.

I've been rocking raid 5/6 btrfs for years for my personal data, no problems apart from the speed. A scrub literally takes months.
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