Using GTP and glabel for ZFS arrays

[Daniel O'Connor]

On 22/07/2010, at 13:59, Adam Vande More wrote:
> To be clear, we are talking about data partitions, not the boot one.
> Difficult for me to explain concisely, but basically it has to do with seek
> time.  A mis-aligned partition will almost always have an extra seek for
> each standard seek you'd have on aligned one.  There have been some
> discussions about in the archives, also this is not unique to FreeBSD so
> google will have a more detailed and probably better explanation.

Newer disks have 4kb sectors internally at least, and some expose it to the OS.

If you create your partitions unaligned to this every read and write will involve at least one more sector than it would otherwise and that hurts performance.

The disks which don't expose it have a jumper which offsets all accesses to Windows XP's performance doesn't take a dive but I'm not sure if that helps FreeBSD.

--
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
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