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Btrfs Coming to Fedora 33

fedoramagazine.org

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Re: Btrfs Coming to Fedora 33

#2
btrfs has made some headlines in the past about its severely broken checksum computation in RAID modes, which rules them out for production use, i.e. https://phoronix.com/scan.php?page=news_item&px=Btrfs-RAID-5...

The wrong parity and unrecoverable errors has been confirmed by multiple parties. The Btrfs RAID 5/6 code has been called as much as fatally flawed

It would be interesting to know if this has been addressed already.

The big fat red warning on btrfs' own wiki page is not inspiring trust either: https://btrfs.wiki.kernel.org/index.php/RAID56

For data, it should be safe as long as a scrub is run immediately after any unclean shutdown

Re: Btrfs Coming to Fedora 33

#3
I just herd my roommate saying "i don't want to play too much with my amd cpu overclocking because if i crash my system too much btrfs might get corrputed again".

laughs in zfs

Re: Btrfs Coming to Fedora 33

#4
post #2

btrfs has made some headlines in the past about its severely broken checksum computation in RAID modes, which rules them out for production use, i.e. https://phoronix.com/scan.php?page=news_item&px=Btrfs-RAID-5... The wrong parity and unrecoverable errors has been confirmed by multiple parties. The Btrfs RAID 5/6 code has been called as much as fatally flawed It would be interesting to know if this has been addressed…

I don't understand why you were downvoted. That is huge and I did not see this detailed in the original article and not even heard about it before.

Re: Btrfs Coming to Fedora 33

#5
post #2

btrfs has made some headlines in the past about its severely broken checksum computation in RAID modes, which rules them out for production use, i.e. https://phoronix.com/scan.php?page=news_item&px=Btrfs-RAID-5... The wrong parity and unrecoverable errors has been confirmed by multiple parties. The Btrfs RAID 5/6 code has been called as much as fatally flawed It would be interesting to know if this has been addressed…

It's interesting to see how Synology "solves" this problem: https://www.synology.com/en-global/knowledgebase/DSM/tutoria...

Re: Btrfs Coming to Fedora 33

#6
post #2

btrfs has made some headlines in the past about its severely broken checksum computation in RAID modes, which rules them out for production use, i.e. https://phoronix.com/scan.php?page=news_item&px=Btrfs-RAID-5... The wrong parity and unrecoverable errors has been confirmed by multiple parties. The Btrfs RAID 5/6 code has been called as much as fatally flawed It would be interesting to know if this has been addressed…

There are some modes that are horribly broken in btrfs (e.g. most of RAID except RAID1), but the common options are safe and in continuous use.

Re: Btrfs Coming to Fedora 33

#7
post #2

btrfs has made some headlines in the past about its severely broken checksum computation in RAID modes, which rules them out for production use, i.e. https://phoronix.com/scan.php?page=news_item&px=Btrfs-RAID-5... The wrong parity and unrecoverable errors has been confirmed by multiple parties. The Btrfs RAID 5/6 code has been called as much as fatally flawed It would be interesting to know if this has been addressed…

It's interesting to see how Synology "solves" this problem: https://www.synology.com/en-global/knowledgebase/DSM/tutoria...

[deleted]

Re: Btrfs Coming to Fedora 33

#8
post #2

btrfs has made some headlines in the past about its severely broken checksum computation in RAID modes, which rules them out for production use, i.e. https://phoronix.com/scan.php?page=news_item&px=Btrfs-RAID-5... The wrong parity and unrecoverable errors has been confirmed by multiple parties. The Btrfs RAID 5/6 code has been called as much as fatally flawed It would be interesting to know if this has been addressed…

It's interesting to see how Synology "solves" this problem: https://www.synology.com/en-global/knowledgebase/DSM/tutoria...

Exactly the same way ReadyNAS solves it...

Re: Btrfs Coming to Fedora 33

#9
I've quickly skimmed the discussion on fedora-devel regarding btrfs. I wondered mainly how they'd handle the various cases where btrfs does not work well, e.g. files that change often inline (databases, VMs, etc). Apparently an application can tell to treat those files differently. So it's basically a matter of fixing various software to work nicely with btrfs as well as any similar filesystem. As mentioned in the thread, openSUSE already uses btrfs for loads of years. I do wonder why it isn't more supported by upstream software (postgres, VM things, etc).

I was also surprised how good the discussion was on fedora-devel. It seems that people didn't break into camps of "over my dead body", and "if we do not do this I'll leave", etc. It seemed more like a "this is my really thought out proposal, but is it actually feasible or did I forget anything". Then people raised problems, sometimes the proposer(s) already had a solution, sometimes it was something they didn't think of. What's nice is that despite seeing various problems everyone seemed to understand that people are trying to improve things.

I didn't read fedora-devel for many years so that was a welcome change over the past.

Re: Btrfs Coming to Fedora 33

#10
post #2

btrfs has made some headlines in the past about its severely broken checksum computation in RAID modes, which rules them out for production use, i.e. https://phoronix.com/scan.php?page=news_item&px=Btrfs-RAID-5... The wrong parity and unrecoverable errors has been confirmed by multiple parties. The Btrfs RAID 5/6 code has been called as much as fatally flawed It would be interesting to know if this has been addressed…

I configured BTRFS for my data a couple of years ago on my Debian machine. It's using RAID10 - and the RAID 5/6 issue was widely known back then so I did not dare to touch that.

I must say that (fingers crossed) until now I haven't had any issues with it. There have been a couple of unclean shutdowns that haven't led to any corruptions. Scrub runs every couple of weeks and on top of that the data has an offline (external disk) and off-site (rsync.net through borgbackup) backup. I'm not expecting BTRFS to let me down, but if it does I have recovery options. I tend to be very careful with my 17+ years of photo archives, especially since I'm generating hundreds of megabytes of new content every week since my daughter was born.

It definitely doesn't look good that RAID 5/6 is broken, but I feel very safe using the other stable RAID modes.

Sometimes I'm dreaming of setting up ZFS - however the downside of that is that it doesn't live in the kernel and you're forced to work with kernel modules. It's certainly doable, but since I had a kernel module issue with Wireguard a few months ago I'll be "looking the cat out of the tree" for a bit more before I decide if I actually want to make the move. For now BTRFS feels stable for me, so until that changes - or the benefits of ZFS increase by a fair amount - I'll probably stay on this.

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