On Thu, Aug 2, 2012 at 1:15 PM, Andreas Dilger <adilger@xxxxxxxxxxxxx> wrote: > > On 2012-07-29, at 12:08, Arne Hüggenberg <hueggenberg@xxxxxxxxxxxxxxxxx> wrote: > > > On Jul 29, 2012, at 8:30 PM, Andreas Dilger wrote: > >>>> Unfortunately, the group descriptor size is not printed. > >>> > >>> how can i get the group descriptor size? > >> > >> Possibly with "debugfs stats"? > > > > ~ # debugfs /dev/vg0/lvol1 > > debugfs 1.42.4 (12-June-2012) > > debugfs: stats > > debugfs: stats > > > > Filesystem volume name: <none> > > Last mounted on: /home/filestore_extern_1 > > Filesystem UUID: 8fba4f1b-5311-4c9b-b8bf-def4957dc1bd > > Filesystem magic number: 0xEF53 > > Filesystem revision #: 1 (dynamic) > > Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize > > Filesystem flags: signed_directory_hash > > Default mount options: user_xattr acl > > Filesystem state: clean > > Errors behavior: Continue > > Filesystem OS type: Linux > > Inode count: 521011200 > > Block count: 4168089600 > > Reserved block count: 191127425 > > Free blocks: 2162482117 > > Free inodes: 520936736 > > First block: 0 > > Block size: 4096 > > Fragment size: 4096 > > Reserved GDT blocks: 60 > > Blocks per group: 32768 > > Fragments per group: 32768 > > Inodes per group: 4096 > > Inode blocks per group: 256 > > RAID stride: 16 > > RAID stripe width: 160 > > Flex block group size: 16 > > Filesystem created: Fri Jul 27 17:16:24 2012 > > Last mount time: Sun Jul 29 15:22:23 2012 > > Last write time: Sun Jul 29 20:50:44 2012 > > Mount count: 6 > > Maximum mount count: -1 > > Last checked: Fri Jul 27 17:16:24 2012 > > Check interval: 0 (<none>) > > Lifetime writes: 7662 GB > > Reserved blocks uid: 0 (user root) > > Reserved blocks gid: 0 (group root) > > First inode: 11 > > Inode size: 256 > > Required extra isize: 28 > > Desired extra isize: 28 > > Journal inode: 8 > > Default directory hash: half_md4 > > Directory Hash Seed: ef2ec72a-750b-4822-bd8d-9117faadeaee > > Journal backup: inode blocks > > Directories: 6392 > > Group 0: block bitmap at 2049, inode bitmap at 2065, inode table at 2081 > > 26585 free blocks, 4085 free inodes, 2 used directories, 4084 unused inodes > > [Checksum 0x7d46] > > Group 1: block bitmap at 2050, inode bitmap at 2066, inode table at 2337 > > 4634 free blocks, 4096 free inodes, 0 used directories, 4096 unused inodes > > [Inode not init, Checksum 0x97aa] > > Group 2: block bitmap at 2051, inode bitmap at 2067, inode table at 2593 > > 1020 free blocks, 4096 free inodes, 0 used directories, 4096 unused inodes > > [Inode not init, Checksum 0x571f] > > Group 3: block bitmap at 2052, inode bitmap at 2068, inode table at 2849 > > 2047 free blocks, 4096 free inodes, 0 used directories, 4096 unused inodes > > Surprisingly, the group descriptor size is also not printed here. Looking at the code in mke2fs, it appears the 64-byte size used for filesystems when the 64bit flag is set, regardless of what size the filesystem is, and there is no way to change it. > > It looks like my theory is wrong, but I don't have access to a system to test this. Probably worthwhile to ask Yongqiang Yang (CC'd), who wrote the 64-bit resize code. > I had the same confusion 11 months ago, when the 64-bit resize patchset was first posted, and I posted almost the same question here. My understanding at the end of the mailing list discussion was that you still cannot resize your filesystem beyond 16TB -- even if the 64bit flag is set -- and you may never be able to do so on that filesystem because you are using resize_inode and not meta_bg. There was a patchset posted on this list a few months ago by Yongquiang Yang to do meta_bg expansion, but there hasn't been much action around it from what I have seen (maybe for the 3.7 merge window?). You can read on here: http://permalink.gmane.org/gmane.comp.file-systems.ext4/27718 -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
