I have a filesystem with lots of small files (gentoo portage tree) that I created with a 1024 block size. I resized that filesystem and it resulted in corruption. I am able to consistently reproduce it by resizing a filesystem that was created 512mb with 1024 block size up to 1g. My data was still recoverable, and fortunately it was nothing that can not easily be reproduced, however I could not get it to fsck cleanly. dagron ~ # lvcreate -L 1g resizetest vgtest Volume group "resizetest" not found dagron ~ # lvcreate -L 1g -n resizetest vgtest Logical volume "resizetest" created dagron ~ # mkfs.ext4 -b 1024 -i 2048 /dev/vgtest/resizetest 524288 mke2fs 1.42.7 (21-Jan-2013) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) Stride=0 blocks, Stripe width=0 blocks 262144 inodes, 524288 blocks 26214 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=67633152 64 block groups 8192 blocks per group, 8192 fragments per group 4096 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409 Allocating group tables: done Writing inode tables: done Creating journal (16384 blocks): done Writing superblocks and filesystem accounting information: done dagron ~ # mount /dev/vgtest/resizetest /mnt/tmp dagron ~ # df /mnt/tmp Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/vgtest-resizetest 442212 2318 409584 1% /mnt/tmp dagron ~ # resize2fs /dev/mapper/vgtest-resizetest resize2fs 1.42.7 (21-Jan-2013) Filesystem at /dev/mapper/vgtest-resizetest is mounted on /mnt/tmp; on-line resizing required old_desc_blocks = 2, new_desc_blocks = 4 The filesystem on /dev/mapper/vgtest-resizetest is now 1048576 blocks long. dagron ~ # df /mnt/tmp Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/vgtest-resizetest 900808 -21474833672 21475683202 - /mnt/tmp dagron ~ # umount /mnt/tmp dagron ~ # e2fsck /dev/vgtest/resizetest e2fsck 1.42.7 (21-Jan-2013) ext2fs_check_desc: Corrupt group descriptor: bad block for inode table e2fsck: Group descriptors look bad... trying backup blocks... /dev/vgtest/resizetest: recovering journal e2fsck: unable to set superblock flags on /dev/vgtest/resizetest /dev/vgtest/resizetest: ***** FILE SYSTEM WAS MODIFIED ***** /dev/vgtest/resizetest: ********** WARNING: Filesystem still has errors ********** dagron ~ # uname -a Linux dagron 3.10.4 #13 SMP Tue Jul 30 14:45:19 EDT 2013 x86_64 AMD Athlon(tm) II X4 620 Processor AuthenticAMD GNU/Linux dagron ~ # e2fsck -V e2fsck 1.42.7 (21-Jan-2013) Using EXT2FS Library version 1.42.7, 21-Jan-2013
as of kernel 3.18.2 and e2fstools 1.42.10 this no longer happens.
... and there was even more resize2fs bugs (and even a security bug or two) fixed in 1.42.12. (Wow, a Gentoo user not using a bleeding edge release. :-)