Btrfs Will Finally "Strongly Discourage" You When Creating RAID5 / RAID6 Arrays

[skeevy420]

Benefits like?
I have 4 SSDs set up with mdadm RAID10 and after hours of tuning and testing, I am still not impressed with IOPS and 99% latency is significantly higher than single disk.
BTRFS is right in generally recommending raid 1 (or raid 1c2, c3, ..)

With that setup you could be hitting the limitations of the file system and/or the raid controller. Anecdotally, I've read that F2FS greatly outperforms Ext4 in regards to SSD mirrored stripes.

[sdack]

Do you mean the btrfs RAID-5 code? It isn't "insecure." It's possibly data lossy and buggy.

Your definition of insecure is too narrow. Insecure means it is not secure, as in "your data is not secure". Insecure doesn't just always mean one can gain access privileges or otherwise break into a system. Clearly you're still a bit young and so cannot remember the same times I was referring to. We were less liberal in the past.

[terrywang]

If only more motherboards would have more than one m.2 slots, that is the only reason why I run BTRFS in single mode on my home machine. That said there is some bug in either btrfs, udev or the initramfs script in atleast Ubuntu 20.04 because on new servers that I've set up with BTRFS in RAID1 on the boot drive they very often end up in the initramfs console during boot due to not being able to find a root device.

You can easily source PCIe M.2 NVMe adaptors for desktops, very cheap but still reliable if you know what brand to buy.

I've recently got 3 M.2 to PCIe cards (2 with passive cooling) but haven't used them yet on the only desktop (SFF, only 1 PCIe slots...).

[cynic]

Contrary to popular belief RAID does *NOT* protect you against data corruption. It protects you against drive failure.

yup! btrfs raid, on the other side, does protect you against data corruption too.

[scineram]

What does btrfs do when a disc fails in RAID1?

For UNRAID I heard there is a zfs plugin for it. I think Wendell talked about it? Maybe I misremember and it was Proxmox.

[zxy_thf]

UNRAID doesn't seem to try to fix many problems (no bitrot prevention) and give priority to data integrity on a professional level. It seems a pretty GUI for containers and a well designed flexibility in terms of data pool expansion

unRAID is a no go for me because of its proprietary natural, but it's still the most popular choice.
Personally I would use SnapRAID instead.

[Space Heater]

The hyperscalers (and their ilk) generally do not try to repair a broken server/filesystem, they blow the instance away and reinstall/rebuild from scratch

Exactly, which is why I'm not holding my breath for any of the btrfs raid issues to get developer attention.

[drjohnnyfever]

So it would be relatively pointless to post the obligatory "ZFS RaidZ1/2/3 work really well". But I will say that I've been extremely happy with it. And they came out with RaidZ3 specifically because of the risk of disk failures during rebuilds with very large disks.

No matter what FS/Vol management you are using for peak performance stripes and/or stripes-of-mirrors are the way to go.

[horizonbrave]

Fortunately unRAID and similar solutions are getting popularity so I don't need to look for RAID on btrfs anymore.

UNRAID doesn't seem to try to fix many problems (no bitrot prevention) and give priority to data integrity on a professional level. It seems a pretty GUI for containers and a well designed flexibility in terms of data pool expansion

[horizonbrave]

I need to stop procrastinating and set up an alert mail server in this box

ZFS has a built-in email alert system, doesn't BTRFS have one or any plans that you know it might be implemented?
Thanks