16 comment

  1. # dumpe2fs /dev/hda3grep -i superblock
    above command is not running here |(pipe) is missing, anyway

    I am getting different output as you mentioned
    [root@sachan /root]# dumpe2fs /dev/hda1 | grep -i superblock
    dumpe2fs 1.19, 13-Jul-2000 for EXT2 FS 0.5b, 95/08/09
    [root@sachan /root]#

  2. Hi Vivek,

    I have a doubt as how many redundant backups of superblock are created in the file system ? Is it made on every block group or only on initial few block groups ?
    In the filesystem that I created of size 128 MB with 16 block groups, when I run the dumpe2fs command on it, it gives the info on superblocks (These are not the exact wordings of the output ) :
    primary superblock is present on block group 0,
    back up superblock is present on block group 1, 3, 5, 7, 9.

    Similarly for a file system with 256 MB size and 31 block groups, primary superblock is present on block group 0 and backups are present on block groups 1,3,5,7, and 9.

    So my doubt is how does the file system how many backups of the superblock to be created ?
    And the same doubt for block group descriptors as well. Block group descriptors are not present in each block group but only in the block groups where superblock is present.

    Hoping for an earliest response.


  3. Hey this command id not working on my system…

    [sunilv@lnx202-28 ~]$ dump2fs /u/sunilv | grep -i superblock
    dump2fs: Command not found.

  4. Use full path /sbin/dumpe2fs, you are logged in as regular user and /sbin and /usr/sbin not in PATH settings.

  5. To Swapnil,

    You have sparse_super mode so super block and backups are saved in groups 0,1,3^n,5^n,7^n (e.g. 0,1,3,5,7,9,25,27,…). If you take a look at mke2fs code, you’ll see these places where super blocks are saved.

    p.s. this is a very late comment but just wanted to comment..

  6. so… what the hell is Superblock, and can you please please be careful using the word/term …. “OBJECT” . You just cant use it at your whim.

  7. is it possible to install linux in personal lappies? core2duo processor( dell laptop)…
    is it possible even vmware workstation is installed in laptops….

  8. Good content; I like how you explain this topic very simply, as linux is typically hard to grasp.

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