BTRFS Raid 6

[Marten]

@thro

How do you propose RAID5/RAID6 actually validate data without using all drives at the same time?

Its a media server. So sucks to be a lazy media server.

[Marten]

@thro

How do you propose RAID5/RAID6 actually validate data without using all drives at the same time?

Also, if you’re flogging one drive with a scrub in a RAID5/RAID6 disk set, given that disk is required to read or write the stripes, performance is doing to be fucked anyway.

All you’re really doing by doing one drive at a time (checksums on individual blocks on the drive?) is prolonging the scrub really.

The more I hear/read about Btrfs, the more it is clear they thought they could do a better job than ZFS without actually understanding the problem.

It started when I made it… and it still working fine. I need to add 2 more 12 TB drives to spread the load. Space however is so open.

[Marten]

List a command that make spence and i will run it … but its working fine for me… I do doubt the raid 6 checking. Because knowone is publishing it and the kernel and BRTFS changes fast.

[Marten]

@starshipeleven

Raid56 on btrfs is not usable on production, the tools warn you that its experimental and that its not usable in production, when you create the raid56 array

This whole thread and its still working

[starshipeleven]

@Marten

List a command that make spence and i will run it

Whats make spence

@Marten

the kernel and BRTFS changes fast.

Not the raid56 mode. I have not seen much activity on that in a while.

Not even fixing basic things like the scrub logic.

They just put up the signs in 2021 to warn people to not use it and thats it.

@Marten

This whole thread and its still working

Without scrub, how do you even know. As long as a small amount of metadata is not corrupted any array will mount, thats not a big accomplishment.

[Marten]

Use your words, im the same

[thro]

@starshipeleven

How about you read the linked source? Launching a scrub on a single drive still means it has to read from the others too because its a stripe.

I did.

Hence my wikipedia link.

[starshipeleven]

If you did, you wouldn’t be asking things like

@thro

How do you propose RAID5/RAID6 actually validate data without using all drives at the same time?

Because it’s literally explained there that scrubbing a single drive does read from the whole array.

@thro

Hence my wikipedia link.

Careful throwing Donning-Kruger so liberally. That cuts both ways, you sound very confident stating btrfs developers just suck.

Imho it’s mostly a matter of “who pays the bills”. Btrfs development and maintenance is more or less bankrolled by Meta/facebook and Suse. Neither seem to care much about raid5/6 so after they covered their needs the masters yanked the chain and development of new features slowed down massively.

ZFS’s core functionality included raid5/6 because it was developed a long time ago when that was still a hot feature to have.
bacchefs is a near-solo project from a dude that is financed through patreon, so he can actually work for the people or whatever he feels like (hence why bcachefs does have radi5/6 working)