On Thu, Dec 28, 2017 at 08:41:13PM -0500, Steve Litt wrote: > On Fri, 29 Dec 2017 01:15:10 +0100 > Harald Arnesen <[email protected]> wrote: > > > I see what you mean, and I have never had a problem with ext4 either. > > But I have used btrfs on all my main machines for the last years, and > > have not had any (filesystem) problems with them either. I'd like to > > see empirical evidence that ext4 is so much more stable than btrfs. > > I can't give you empirical evidence. It's a guess on my part.
Here's one: when ext4 is running on flaky hardware, it gives hard to diagnose errors that at the first glance don't look like disk corruption at all: mostly, you get random segfaults. Btrfs on the other hand immediately informs you what's wrong. Failure mode on this relatively frequent problem is quite nasty. But, not all is lost. ext4 has recently grown metadata (only) checksums, and having them protects you from worst kinds of corruption. As is, data corruption is localized, metadata breakage can kill the whole filesystem. You also get a random chance to be notified of problems with disk cable/ controller/etc, as a bad write or read will hit a metadata block sooner or later. Thus, if you created your filesystem with mkfs.ext4 older than stretch/ascii, it's vital that you do the following, on an unmounted filesystem (ie, need to boot from alternate media if it's /): resize2fs -b $DEV tune2fs -O metadata_csum $DEV fsck.ext4 -D $DEV There's a caveat that such a filesystem can't be mounted with kernels prior to 3.6 (I found this the hard way, after mkfs-ing on unstable), but by now, this shouldn't be a concern as even jessie has 3.16. Unrelated: while you're at it, give tytso a big thumbs-up for the third paragraph of "man resize2fs". These wise words deserve a beer donation. Meow! -- // If you believe in so-called "intellectual property", please immediately // cease using counterfeit alphabets. Instead, contact the nearest temple // of Amon, whose priests will provide you with scribal services for all // your writing needs, for Reasonable And Non-Discriminatory prices. _______________________________________________ Dng mailing list [email protected] https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
