From owner-freebsd-current@FreeBSD.ORG  Mon Dec 19 22:16:17 2011
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Date: Mon, 19 Dec 2011 22:16:17 +0000
From: Alexander Best <arundel@freebsd.org>
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Cc: freebsd-fs@freebsd.org
Subject: can a wrong alignment cause a decrease in a hdd's life expectancy?
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hi there,

i'm using a usb hdd with the following specs:

otaku% sudo smartctl -i /dev/da0
smartctl 5.42 2011-10-20 r3458 [FreeBSD 10.0-CURRENT amd64] (local build)
Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital My Passport Essential SE (USB, Adv. Format)
Device Model:     WDC WD10TMVW-11ZSMS4
Serial Number:    WD-WXJ1A81C1845
LU WWN Device Id: 5 0014ee 1af1e4483
Firmware Version: 01.01A01
User Capacity:    1,000,204,886,016 bytes [1,00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   8
ATA Standard is:  Exact ATA specification draft version not indicated
Local Time is:    Mon Dec 19 23:00:43 2011 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

unfortunately i didn't align it properly using gpart(8)'s -a switch.
performance wise it shouldn't cause any issues, because i'm accessing this hdd
through usb 2 exclusively. however my concern is that using an alignment of 512
will put an extra workload onto the hdd (doing the conversion -> 4096). will
this reduce my hdd's life expectancy? in that case i might consider
re-partitioning it (with proper alignment settings).

cheers.
alex

ps: the hdd only gets mounted read-only!