erle wrote: >so you will have to try starting from block 1 ( useless now b/c if it was >working .. u wouldn't be trying this.) in multiples of your filesystem. from >what I gather its not stored at each multiple... but at a few of them. >long & tediuos perhaps.. but serves you . .... me ? :-) right for not >storing those superblock backups. >( for those of you giggling away... no I did not do this 80 times... ) > >if that doesn't work... my guess is... Format
I had faced a similar problem long ago ... the documentation for the disktools (I do not remember which one) does mention the most likely number to use for the alternate superblock, and it works under most systems ... you do not need to try out every block. I am not anywhere near my Linux box right now [it's all powered down and wrapped up in the lab], but I am pretty sure its the fsck manpage that mentions these numbers. Here's what I had found in a file called "Design and Implementation of the Second Extended Filesystem" , meant for the Kernel Hackers Guide. I don't have the URL anymore, but similar information is probably just a google search away. "A filesystem is made up of block groups. Block groups are analogous to BSD FFS's cylinder groups. However, block groups are not tied to the physical layout of the blocks on the disk, since modern drives tend to be optimized for sequential access and hide their physical geometry to the operating system. Each block group contains a redundant copy of crucial filesystem control informations (superblock and the filesystem descriptors) and also contains a part of the filesystem (a block bitmap, an inode bitmap, a piece of the inode table, and data blocks). Each block group contains a redundant copy of crucial filesystem control informations (superblock and the filesystem descriptors) and also contains a part of the filesystem (a block bitmap, an inode bitmap, a piece of the inode table, and data blocks)." HTH, SameerDS. -- MTech Student, Reconfigurable Computing Lab, KReSIT, IIT-Bombay _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com _______________________________________________ http://mm.ilug-bom.org.in/mailman/listinfo/linuxers
