Hello guys, I have some difficulties to understand what really are the numbers behing "df" and tune2fs. You'll find the output of tune2fs and df below, on which my maths are based. Here are my maths: A tune2fs on an ext3 FS tell me the FS size is 3284992 block large. It also tell me that the size of one block is 4096 (bytes if I'm not wrong?). So my maths tell me that the disk is 3284992 * 4096 = 13455327232 bytes or 13455327232 / 1024 /1024 /1024 = 12.53 GB. A df --block-size=1 on the same FS tell me the disk is 13243846656 which is 211480576 bytes smaller than what tune2fs tell me. In gigabytes, it means: * for df, the disk is 12.33 GB * for tune2fs, the disk is 12.53 GB I thought that maybe df is only taking into account the real blocks available for users. So I tried to remove the reserved blocks and the GDT blocks: (3284992 - 164249 - 801) * 4096 = 12779282432 or in GB : 12779282432 / 1024 / 1024 / 1024 = 11.90 Gb ... My last thought was that "Reserved block" in tune2fs was not only the reserved blocks for root (which is 5% per default on my system) but take into account all other reserved blocks fo the fs internal usage. So: (3284992 - 164249) * 4096 = 12782563328 In GB : 11.90 Gb (the difference is not significative with a precision of 2. So I'm lost ... Is someone have an explanation? I would really really be grateful. Nicolas ------------------------------ --------- Here is the output of df and tune2fs : $ tune2fs -l /dev/mapper/datavg-datalogslv tune2fs 1.41.9 (22-Aug-2009) Filesystem volume name: <none> Last mounted on: <not available> Filesystem UUID: 4e5bea3e-3e61-4fc8-9676-e5177522911c Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file Filesystem flags: unsigned_directory_hash Default mount options: (none) Filesystem state: clean Errors behavior: Continue Filesystem OS type: Linux Inode count: 822544 Block count: 3284992 Reserved block count: 164249 Free blocks: 3109325 Free inodes: 822348 First block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 801 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 8144 Inode blocks per group: 509 Filesystem created: Wed Aug 28 08:30:10 2013 Last mount time: Wed Sep 11 17:16:56 2013 Last write time: Thu Sep 12 09:38:02 2013 Mount count: 18 Maximum mount count: 27 Last checked: Wed Aug 28 08:30:10 2013 Check interval: 15552000 (6 months) Next check after: Mon Feb 24 07:30:10 2014 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: ad2251a9-ac33-4e5e-b933-af49cb4f2bb3 Journal backup: inode blocks $ df --block-size=1 /dev/mapper/datavg-datalogslv Filesystem 1B-blocks Used Available Use% Mounted on /dev/mapper/datavg-datalogslv 13243846656 563843072 12007239680 5% /logs -- Nicolas MICHEL _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
