btrfs checksums/scrubbing

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I've not used BTRFS in unRAID yet. Ordered Unraid 6 on a USB 3 drive not to long ago and its in the mail. But I did test BTRFS on the 3.19.3 kernel on my Sabayon tower and I can report it is DISASTROUS! I made a RAID10 of 4 1TB HDDs (WD REDS) in a new ICY DOCK USB3 enclosure. All went well at first and I began debating ditching ZFS for a more Linux friendly/supported FS. So I started to migrate (copy) all my data (~1.8TB) off my FreeNAS VM through the network to this BTRFS RAID. Worked great for several hours and was fairly speedy. Right before the 24 hr marker I noticed all my files had "finished" being copied over. I went to double check only to find about 1TB of data and the drive had been marked RO? I looked in dmesg and found tons of complaints about metadata corruption on "sdg". Looked into it, this is a known common issue until kernel 3.19.5 and there IS NO FIX. I would have to remove the drive from the RAID, wipe it, then re-add it to the RAID. SMART data shows drive is fine and all works fine with ZFS.


Sadly BTRFS is garbage and instable in my eyes. If I lose a drive in RAID10 due to the FS in less than 24hrs, forget that crap! I'd much rather have ZoL.  Devs who claimed businesses should use this FS as "it is stable now" are a bunch of liars and are full of it. Wait for 4.0 kernel or.. wait until someone else takes a dive and it works. I'll probably give it another try when 4.0 comes out and if I see good reviews.


Please devs, include ZFS support with the 4.0 kernel. I like my data and prefer to keep it.

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Darksurf, I'd think about trying BTRFS on native SATA before dismissing it as disastrous.  The chipset used in those IcyBox RAID enclosures is a bit...well, cheap and rubbish.


What you've done is like taking a Ferrari out on the track fitted with LingLong Ditchfinder tyres, and saying that Ferraris are rubbish because they go off the track on the first corner. 

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HellDiverUK, I'd thought about that myself. But I checked the BTRFS website (as well as several other angry sources) and its a known issue and claims to be fixed in 3.19.5 and 4.x Going forward. So this exact issue is INDEED a BTRFS issue. RAID isn't Hardware raid either, its BTRFS software RAID. Until I see it proven solid, the cake is a lie.

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Can anyone shed some light on how the btrfs checksum/scrubbing is implemented in 6.0?  There doesn't seem to be any documentation for it yet and I'd really like to start using/testing it on the array disks.



Have you clicked the help button on the webgui after clicking on a btrfs disk device?  There is info there about it.

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