Is btrfs still super slow at deleting large files?
It can take multiple seconds (like 5-10) on my fileserver to delete just one ~10GB file.
Btrfs Coming to Fedora 33
11–20 of 140 posts
Re: Btrfs Coming to Fedora 33
#12btrfs 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...
I really don't trust Synology anymore, had so many destroyed Raid's in the past mainly with RS407.
I buy a old Workstation slap FreeBSD with ZFS (RaidZ1 or 2) on it, and i am much happier.
Re: Btrfs Coming to Fedora 33
#13btrfs 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.
>but the common options are safe and in continuous use
Which would be Raid5/6 and 1
Re: Btrfs Coming to Fedora 33
#14btrfs 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.
Fanboys...there was even a time when peoples defended Windows for being the best server-OS, and no one needs check-summing in the FS because HW-raid is the "professional" way.
Re: Btrfs Coming to Fedora 33
#15btrfs 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...
Synology has solved it by running btrfs on top of mdraid, then patching it so that btrfs reports errors to mdraid and putting repair code into mdraid. This reliably works.
I'm sure some would be interested in this, but Synology seems to not take GPLv2 too seriously and nobody seems to care about this.
RAID 5/6 in btrfs is relatively neglected because the big users that pay developers to work on btrfs (and put the work up-stream) don't care that much about it. E.g. Facebook is probably using it for their HDFS storage, so HDFS gives them the RAID functionality.
Re: Btrfs Coming to Fedora 33
#16Earlier quoted context omitted.
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...
I observed that on my ReadyNAS too and always thought it was a weird setup.
Now I know there are proper reasons for it. Good to know.
Re: Btrfs Coming to Fedora 33
#17I'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 th…
> 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).
It least for default libvirt locations fedora disables CoW (chattr +C). No change in software needed.
Re: Btrfs Coming to Fedora 33
#18Earlier quoted context omitted.
It's interesting to see how Synology "solves" this problem: https://www.synology.com/en-global/knowledgebase/DSM/tutoria...
Synology has solved it by running btrfs on top of mdraid, then patching it so that btrfs reports errors to mdraid and putting repair code into mdraid. This reliably works. I'm sure some would be interested in this, but Synology seems to not take GPLv2 too seriously and nobody seems to care about this. RAID 5/6 in btrfs is relatively neglected because the big users that pay developers to work on btrfs (and put the wor…
They use it for everything except MySQL databases, which are stored on XFS.
There was a recent discussion on LKML where Chris Mason (I think) described all this.
Re: Btrfs Coming to Fedora 33
#19I'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 th…
>databases, VMs, etc
You should disable CoW and Caching on the filesystem/-set where VM and Databases-files reside, but that counts for ZFS as well...well for all CoW-FS's in fact.
Re: Btrfs Coming to Fedora 33
#20btrfs 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…
Raid 5/6 isn't exactly relevant to this article, given its about laptop/desktop default file system. And the installer won't let you do raid5/6.
Anyway a current write-up on btrfs raid 5 here:
https://lore.kernel.org/linux-btrfs/20200627032414.GX10769@h...
Includes this observation:
"btrfs raid5 is quantitatively more robust against data corruption than ext4+mdadm (which cannot self-repair corruption at all), but not as reliable as btrfs raid1 (which can self-repair all single-disk corruptions detectable by csum check)."
But worth reading the whole thing.