Hello, not sure if i have proper skill to do that LVM/ext4 test. I found this - https://www.phoronix.com/scan.php?page=news_item&px=Linux-4-EXT4-RAID-Issue-Found Maybe there is some connection? On Tue, Jan 26, 2016 at 5:51 PM, Duncan <1i5t5.duncan@xxxxxxx> wrote: > John Smith posted on Tue, 26 Jan 2016 15:32:21 +0100 as excerpted: > >> i finished with testing and corruption (different hashes) happens only >> from lvm -> to btrfs, lvm -> lvm. >> >> Also i count sha256 on the same file on lvm 3x and i got 3 different >> hashes. >> >> Is it still hw issue or bug in LVM/ext4? > > That does seem to clear btrfs, but it could be either ext4 or lvm, or > under the lvm at the physical volume level, and hardware is still a > possibility as well, tho rather less likely, as btrfs likely stresses the > hardware more than lvm or ext4. > > The next question is whether it's the ext4 or lvm layer. There are two > ways to test it that I can think of. > > One would be to run an sha256 hash test directly on the logical volume > the filesystem is normally created on (with the lvm assembled in read- > only mode and/or without the filesystem on top of it mounted or mounted > read-only). Does that return the same hash when run multiple times? > > Obviously the problem there is the size of the logical volume; getting a > hash of the entire raw volume is likely to take some time. But this > should be the best test as it eliminates the filesystem from the equation > entirely. > > Another alternative would be trying some filesystem other than ext4 on > the logical volume, say btrfs, xfs or reiserfs. > > Either way, if the errors remain without ext4 being in the picture, > either because you're hashing the raw device or because you're using some > other filesystem, then that pretty well clears ext4. If the errors go > away, then heading to the ext4 list would probably be best, as ext4 would > seem to be the culprit. > > If there's still errors at the logical volume device level, then the next > question is whether they appear on the raw physical volumes that the > logical volume is assembled out of, or not. Again, I'd suggest hashing > the raw devices repeatedly and see if they return the same hashes each > time. If not, then it's likely either the hardware or the device driver, > and you'd contact the device driver maintainer. (Here, I'd probably file > a bug on kernel bugzilla, YMMV.) If the raw physical devices hash > consistently while the LVM logical volume doesn't, then it's time to > contact the LVM folks. > > -- > Duncan - List replies preferred. No HTML msgs. > "Every nonfree program has a lord, a master -- > and if you use the program, he is your master." Richard Stallman > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
