On 2011-04-09, at 12:39 PM, Roman Mamedov wrote: > Here's what happened. I reshaped my RAID5 to a RAID6 and a larger disk count. > Then I ran "resize2fs /dev/md0". It successfully enlarged the filesystem > online (that took a couple of hours, I think). The online resize shouldn't take more than a few minutes, unless the disk is crazy busy and you are going from 16GB to 16TB or something. > Since my count of disks changed, I thought I should change the array stripe > width. Then, while still not unmounting the filesystem, I did: > > tune2fs -E stripe_width=48 /dev/md0 This does nothing more than set a field in the superblock, and it only gives a hint to the allocator to align the files on multiples of 48-block boundaries. > Then I started copying files from another array to the one on which the above > operations were conducted. I did: > > cp -Rp /mnt/array1/data/* /mnt/array2/new-data/ What kernel version do you have, and what version of coreutils? Is this perhaps a bleeding-edge kernel/coreutils with the "FIEMAP" bug? > This completed successfully. No errors on the console, silence in dmesg. > > Then I thought I'd verify the destination, just to be sure. Luckily, I have > checksums stored in almost every directory as .SFV files (created with "cfv"). > > And some checksums did not match. On a closer investigation, it appears like > some files deep down in the directory tree (and with a rare occurence, > something like one file in a thousand) were truncated during copying. E.g. > they'd have size of 188 MB instead of 349 MB, or 128 MB instead of 170 MB. > Some files (originally less than 1 MB in size) just had zero-length on the > destination. Were the source files that had problems recently written themselves in this case? > Other than these truncations, there is NO corruption of data inside any of the > files. Which kinda rules out CRC-style errors in controller/disk/cable. > > So.. this is completely puzzling to me, and I suspect either a kernel bug, or > my mistake, and tune2fs cannot modify a mounted FS (however it did NOT show any > warning that the FS was mounted, and if this is the case, it should've > absolutely refused to operate on a mounted FS). > > Any ideas? :) > > -- > With respect, > Roman Cheers, Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
