2018-01-23 13:51 GMT+01:00 Austin S. Hemmelgarn <ahferro...@gmail.com>: > On 2018-01-22 21:35, Chris Murphy wrote: >> >> On Mon, Jan 22, 2018 at 2:06 PM, Claes Fransson >> <claes.v.frans...@gmail.com> wrote: >>> >>> Hi! >>> >>> I really like the features of BTRFS, especially deduplication, >>> snapshotting and checksumming. However, when using it on my laptop the >>> last couple of years, it has became corrupted a lot of times. >>> Sometimes I have managed to fix the problems (at least so much that I >>> can continue to use the filesystem) with check --repair, but several >>> times I had to recreate the file system and reinstall the operating >>> system. >>> >>> I am guessing the corruptions might be the results of unclean >>> shutdowns, mostly after system hangs, but also because of running out >>> of battery sometimes? >> >> >> I think it's something else because I intentionally and >> unintentionally do unclean shutdowns (I'm really impatient and I'm a >> saboteur) on my laptop and I never get corruptions. In 18 months with >> an HP Spectre which doesn't even have ECC memory, and has an NVMe >> drive, *and* really remarkable for almost half this time I used the >> discard mount option which pretty much instantly obliterates unused >> roots, even when referenced in the super block as backup roots - and >> yet still zero corruption. No complaints on mount, scrub, or readonly >> checks. *shrug* >> >> Anyway I suspect hardware or power issue. Or even SSD firmware issue. > > I would tend to agree here, with one caveat, if it's a laptop that's less > than 3 years old, you can probably rule out power issues. Some more info on > the particular system might help identify what's wrong.
Hi, I boughtThe laptop new in July 2014, but have had corruption issues with btrfs I think as long as I have been trying it, since the end of 2014 I think. You can find addtitional info about my laptop in my original post, please let me know if you want som more info. >> >> >>> Furthermore, the power-led has recently started blinking (also when >>> the power-cable is plugged in), I guess because of an old and bad >>> battery. Maybe the current corruption also can have something to do >>> with this? However I almost always run with power cable plugged in in >>> last year, only on battery a few seconds a few times when moving the >>> laptop. >>> >>> Currently, I can only mount the filesystem readonly, it goes readonly >>> automatically if I try to mount it normally. >> >> >> Btrfs is confused and doesn't want to make the corruption worse. > >>> >>> >>> Fstab mount options: noatime,autodefrag (I have been using the option >>> nossd with older kernels one period in the past on the filesystem). >>> >>> If it matters, I have been running duperemove many times on the >>> filesystem since creation. >> >> >> I don't think it's related. >> >> >>> >>> To test the RAM, I have been running mprime Blend-test for 24 hours >>> after the corruption without any error or warning. >> >> >> I'm not familiar with it, pretty sure you want this for UEFI: >> >> https://www.memtest86.com/download.htm >> >> Where you can use that or memtest86+ if the firmware is BIOS based. > > Do keep in mind that just because it passes memory checks does not mean it's > not an issue with the RAM. Memory testers rarely throw false positives, but > it's pretty common to get false negatives from them.> Okay, thanks for telling me. >>> >>> I have never noticed any corruptions on the NTFS and Ext4 file systems >>> on the laptop, only on the Btrfs file systems. >> >> >> NTFS and ext4 likely won't notice such corruptions either (although >> new ext4 volumes any day now will have checksummed metadata by >> default) as they're weren't designed with such detection in mind. > > This is extremely important to understand. BTRFS and ZFS are essentially > the only filesystems available on Linux that actually validate things enough > to notice this reliably (ReFS on Windows probably does, and I think whatever > Apple is calling their new FS does too). Even if ext4 did notice it, it > would just mark the filesystem for a check and then keep going without doing > anything else about it (seriously, the default behavior for internal errors > on ext4 is to just continue like nothing happened and mark the FS for fsck). Well, personally I think it would be great if I (optionally) could do that with Btrfs too. Even if it notice me of corruption and I might even lose e few files, I think it would be good if I could continue to use the filesystem with normal read/write capabilities, so I wouldnt need to reinstall the operating system. Best regards, Claes -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
