FFS - Still using rotational delay with modern disks?

Dieter BSD dieterbsd at engineer.com
Mon Dec 17 21:44:21 UTC 2012

The newfs man page says:

 -a maxcontig
 Specify the maximum number of contiguous blocks that will be laid
 out before forcing a rotational delay.  The default value is 16.
 See tunefs(8) for more details on how to set this option.

Is this still a good idea with modern drives where the number of
sectors per track varies, and no one but the manufacturer knows how
many sectors a particular track has? [1] Skipping sectors could
unnecessarily force a seek to the next track, thus hurting rather
than helping performance.

I have to wonder if FreeBSD even supports any hard drives that
don't use zone bit recording?

The tunefs man page does not mention this parameter.

[1] http://en.wikipedia.org/wiki/Zone_bit_recording

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