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SubjectRe: e2fs block to physical block translation

[Al Peat]
> Quick question about blocks:
> If I assume my hard drive uses 512 blocks, and my
> ext2 filesystem uses 4k blocks, can I assume the
> following formula for translation?
> physical block # / 8 = e2fs block #

Not if you have a partition table. If you take into account the
individual partition offset, I think your formula is ok.

On a floppy (no partition table) you'd be fine.

It's not always that easy, of course. Think of RAID (logical block
mapping can be a complex formula), LVM (the mapping is stored in a
table in the volume group metadata), CD-ROMs (what exactly do you mean
by "block"...?) and other such.

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