Hello All, After running "e4defrag" on an idle filesystem, I found a single file out of 893084 regular files had become corrupt (md5sum changed). I have repeated the process using an almost identical copy of the original filesystem, and a different single file became corrupt. In both cases the nature of the corruption was the first 4096 bytes of the file being replaced with something different. The remainder of each file was intact. I don't think it's a hardware issue. The machine has ECC RAM, and no I/O errors are being reported. The ext4 filesystem is inside an LVM volume, and the underlying storage is RAID1 md-raid. The system is running vanilla kernel 4.11.3, with e2fsprogs-1.43.4 on an 8 core / 16 thread x86_64 CPU. After the first e4defrag run: # time md5sum --quiet -c CHECKSUMS_home_050617.md5 ./marc/LinuxStuff/Linux4.x/patch-4.10.12.xz: FAILED md5sum: WARNING: 1 computed checksum did NOT match real 62m30.816s user 10m15.144s sys 2m29.436s After the second run: # time md5sum --quiet -c CHECKSUMS_home_050617.md5 ./marc/.mozilla/firefox/jh6wc1il.default/formhistory.sqlite: FAILED md5sum: WARNING: 1 computed checksum did NOT match real 61m45.874s user 10m24.339s sys 2m12.107s Can anyone help pin down the cause of the corruption? I'm happy to repeat the process again (I have an image copy of the original source filesystem) - but the "e4defrag" process takes about 4hours, and it takes a further hour to do the md5sum check - so it's not quick to reproduce. Thanks & Kind Regards, Marc
