From owner-freebsd-fs@FreeBSD.ORG  Mon Dec 19 22:56:33 2011
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Date: Mon, 19 Dec 2011 22:56:33 +0000
From: Alexander Best <arundel@freebsd.org>
To: Poul-Henning Kamp <phk@phk.freebsd.dk>
Message-ID: <20111219225633.GA77147@freebsd.org>
References: <20111219224700.GA75581@freebsd.org>
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Cc: freebsd-fs@freebsd.org, freebsd-current@freebsd.org
Subject: Re: can a wrong alignment cause a decrease in a hdd's life
	expectancy?
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On Mon Dec 19 11, Poul-Henning Kamp wrote:
> In message <20111219224700.GA75581@freebsd.org>, Alexander Best writes:
> >On Mon Dec 19 11, Poul-Henning Kamp wrote:
> >> In message <20111219221617.GA70383@freebsd.org>, Alexander Best writes:
> >> 
> >> >ps: the hdd only gets mounted read-only!
> >> 
> >> There is no known wear-effects in flash storage as long as you
> >> only read.
> >> 
> >> You may need to do refresh-writes every 5-10 years to avoid
> >> tunnel-leakage bit errors, but most flash controllers use semi-long
> >> ECC syndromes and will do so on first bit that gives an read error.
> >
> >this is a regular hdd i believe -- no ssd. at least when i plug it into my
> >usb drive i hear the hdd spinning up and causing vibrations. i don't think
> >that would be the case with an ssd.
> 
> Ahh, sorry, I don't know why I thought it was flash.

no problem. so will the improper alignment also not cause a life expectancy
shortage in case of a hdd (non-flash-based)?

and one other question: the hdd also supports usb 3. will the improper
alignment have any effect (speed wise) when connected via usb 3, or is even
usb 3 too slow to notice the performance drop due to the improper alignment?

cheers.
alex

> 
> 
> -- 
> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> phk@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.