if e2fs is saying that the first backup superblock is at 32768 why do you multiply it by 4 to get the 'real super block backup location? Why doesn't e2fs do the multiplication to give the 'real' location? Is that a bug? If so I think that can be easily fixed. Not by me ( don't have the know-how) but by some one who knows how to program. On Mon, Feb 20, 2012 at 8:59 AM, Matt Graham wrote: > From: Michael Havens > > "sudo e2fsck -b block_number /dev/xxx" > > The first backup superblock was at 131072. Are other > > backup blocks located every 131072? > > No. > > dumpe2fs /dev/mapper/vg-usr32 | grep 'Backup super' > Backup superblock at 32768 > Backup superblock at 98304 > Backup superblock at 163840 > Backup superblock at 229376 > [snip] > > Multiply those by 4, and you see the first backup is 131072, second is > 393216, > third is 655360, fourth is 917504, and they're spread even farther apart as > they go up. A 7.9G filesystem here has 8 backup superblocks, while a 50G > filesystem has 11. I'm not sure how the copies are distributed, but > there's > probably a fairly simple algorithm in the source for mke2fs that describes > it. > > > -- > Matt G / Dances With Crows > The Crow202 Blog: http://crow202.org/wordpress/ > There is no Darkness in Eternity/But only Light too dim for us to see > > --------------------------------------------------- > PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us > To subscribe, unsubscribe, or to change your mail settings: > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss > -- :-)~MIKE~(-: