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SubjectRe: Ext2 defragmentation
On Wed, 17 Nov 1999 13:14:45 -0500, you wrote:

> No, it's not a problem because the backup superblock doesn't need to be
> written to during the course of normal operations. (The critical
> parameters which e2fsck needs to do its thing don't change after the
> filesystem is created; they do change after a resize2fs, though, so some
> care is needed in that case.) So it's just a matter of

I see. I guess I was thinking of the case where the fs was suffciently damaged
so that one would have to kickstart e2fsck with a backup superblock location.
Maybe this never works inpractice so it's not worth the trouble.

> I've noticed another anomaly. When mke2fs 1.18 creates a 1.3GB partition, it
> says the first backup superblock is at 32768 not 32769. Is this an
> off-by-one error?
> No; for 2k and 4k filesystems, the primary superblock is located at
> offset 1024 of block #0. (Where the first 1k of block #0 is reserved
> for the boot loader). On 1k filesystems, primary superblock is located
> at block #1, and so the block group boundaries are shifted down by 1
> block.
> - Ted

Ah, I get it. Thanks for the info.

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