[SOLVED] WARNING!: Ext4 data corruption kernel bug on the prowl.
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See https://lkml.org/lkml/2012/10/24/620
It's from the original reporter of the problem. He says for example: "It occurs to me that it is possible that this bug hits only those filesystems for which a umount has started but been unable to complete. If so, this is a relatively rare and unimportant bug which probably hits only me and users of slow removable filesystems in the whole world..." and "Verified! You do indeed need to do passing strange things to trigger this bug -- not surprising, really, or everyone and his dog would have reported it by now. As it is, I'm sorry this hit slashdot, because it reflects unnecessarily badly on a filesystem that is experiencing problems only when people do rather insane things to it."
So, it seems the bug bites if the system is rebooted or powered off while umount is running but has not yet finished.
I've always had especially bad luck with corrupting data and filesystem's with ext4. That's not to say it's necessarily the the file system's fault, just that it's happened numerous times to me. It's just never been very fault tolerant in my experience. I just now came back to ext4 because it seems like xfs will severely crunch my system for a moment during heavy read/write so it is disconcerting for bugs to be showing up. Anyway I'm not using supposedly affected kernels and I'm still not keeping data on ext4 so we shall see what happens.
I don't know if this was related to the 'ext4' issue but I had a data loss (single file) 2-3 weeks ago. I was working on a project in Qt Creator when there was a power breakage. The UPS (APC but very old) saved me for few seconds but it switched off while PC was still powered. I don't remember the exact PC state at this moment: if I closed QT Creator or if I left KDE or if I started shutdown sequence, it happened so fast.
Next time I loaded the project one of the cpp files was empty (0 length).
Another reason I don't use the popular ext* filesystems. They don't have a good history and it continues up to today.
I would maybe see it the other way around. Because they are popular more bugs are are reported, which gives them a "bad history", but makes them more stable in the end. Like this one occurs only under extreme conditions, but was found nonetheless.
Ext2 filesystem corruption was my main reason for switching mission-critical servers to BSD back in 2000 (and back to Slackware as ext3 settled in). So this is not the first time, but the continuation of a long sad story.
I quit using FreeBSD years ago around the 4.x-5.x series because it would not boot/ or boot and crash because i was using a usb keyboard and other oddities, besides that I never found FreeBSD to be more stable or faster than Linux. I do prefer some of its userland. FreeBSD and NetBSD newish init systems rock, it does not have the LP mess of Pulseaudio and SystemD but the kernels are are trash.
BSD users/devs are still the most elitist pricks this side of Apple. I would love to have a BSD like system with a Linux kernel, the closest I have come is Slackware.
Quote:
Originally Posted by H_TeXMeX_H
Another reason I don't use the popular ext* filesystems. They don't have a good history and it continues up to today.
The EXT's are the least problematic general purpose filesystems in Linux, and better tested and a more bug free better track record than XFS, ReiserFS, JFS, BTRFS.
The EXT's are the least problematic general purpose filesystems in Linux, and better tested and a more bug free better track record than XFS, ReiserFS, JFS, BTRFS.
As people often tell me nowadays: prove it.
Ok, maybe I won't be that mean, how about some examples or articles ?
Honestly I think the bugs are due to bad decisions made by the devs, like when they first released ext4 and made the default 'data=writeback'. It was changed eventually, but it took time and data loss.
Well, I am very happy with Pat's 3.2.29 everywhere but my laptop, where I have to run at least 3.3 on the account of Ivy Bridge. I can't pretend to understand this thread, but it looks like everything from 3.3 and up may be affected, so I guess I just have to not reboot until they fix it
Now that more detail's have come out I don't think there is much cause for concern: unless you're system has a tendency not to shutdown cleanly for some reason.
Now that more detail's have come out I don't think there is much cause for concern: unless you're system has a tendency not to shutdown cleanly for some reason.
I have lost a root file system on one machine last week. I can't say for certain it was the bug in question. It certainly followed precisely the pattern that is said to trigger the bug, but on the other hand the machine wasn't on 3.5.7 yet. I haven't had the time yet to assess the situation and salvage whatever I can, followed by a re-install.
ReiserFS kicks ass. It's not let me down in 12 years of use. Started using it with SuSE 7.3 through openSUSE 11.3, then in Slackware 13.37 and now 14.0
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