File system blocks alignment

Poul-Henning Kamp phk at
Fri Jan 1 11:25:34 UTC 2010

In message <200912311712.18347.pieter at>, Pieter de Goeje writes:

>Ok, as Miroslav wrote, it does not report 4k sectors:

If you care to, and have the time, try the following:

for N in (0...7)
	for M in (0..2)
		create partition starting at byte offset N*512
		newfs -f 4096 -b 32768 /dev/foo
		mount /dev/foo /mnt
		time restore(8) a filesystem into it.
		unmount /mnt
		time fsck_ffs /dev/foo
		mount /dev/foo /mnt
		time tar cf /dev/null  /mnt
		unmount /mnt

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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