I've been toying with ext4 and e2fsprogs pu branch (pulled from git yesterday) on very large volumes, and I've run into some issues. What I've found so far with an 19TB MD RAID0 volume, running 2.6.29.4 (I'm planning on trying 2.6.30 soon): - mkfs.ext4 *appears* to work fine, reporting no errors. Examining the superblock info with dumpe2fs -h looks normal -- although I'm unfamiliar with "Lifetime writes" field, and I'm not sure why it's at 73GB immediately after doing mkfs, before ever mount it. - Immediately running e2fsck on the volume before ever mounting it will not complete, and results in the following: # e2fsck -n /dev/md2 e2fsck 1.41.7 (29-June-2009) Error reading block 2435874816 (Attempt to read block from filesystem resulted in short read). Ignore error? no /dev/md2: Attempt to read block from filesystem resulted in short read while reading block 2435874816 /dev/md2: Attempt to read block from filesystem resulted in short read reading journal superblock e2fsck: Attempt to read block from filesystem resulted in short read while checking ext3 journal for /dev/md2 - Trying to mount normally with no options does not work. The kernel log contains these messages: EXT4-fs: barriers enabled JBD: no valid journal superblock found EXT4-fs: error loading journal. - Mounting with -o noload does appear to work, and reading and writing seems to work fine. - Setting default mount options with tune2fs works fine, as expected. - Then, I went on to check out filesystem resizing. I created an LVM 15TB LV, and ran mkfs.ext4 on it. Looking at the superblock info, it did not contain the 64bit flag, which I assume is expected behavior. I extended the LV to ~18TB and tried resize2fs, and got this error: resize2fs: Can't read an block bitmap while trying to resize /dev/data/data0 If there's anything else anyone would have me try, or any patches to test, just let me know. Thanks! -Justin -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
