Message-ID: <508B3EF8.4000703@vlnb.net>
Date: Fri, 26 Oct 2012 21:55:04 -0400
From: Vladislav Bolkhovitin <vst@vlnb.net>
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To: "Theodore Ts'o" <tytso@mit.edu>, Alan Cox <alan@lxorguk.ukuu.org.uk>,
        =?UTF-8?B?5p2o6IuP56uLIFlhbmcgU3UgTGk=?= <suli@cs.wisc.edu>,
        General Discussion of SQLite Database 
	<sqlite-users@sqlite.org>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        drh@hwaci.com
Subject: Re: [sqlite] light weight write barriers
References: <CALwJ=MzHjAOs4J4kGH6HLdwP8E88StDWyAPVumNg9zCWpS9Tdg@mail.gmail.com> <m2fw5mtffg.fsf_-_@firstfloor.org> <CABK4GYNKF6LCgsQ5SN+dATtRm-0Qh_QmNdqZqZcj6S98z+ofXg@mail.gmail.com> <5086F5A7.9090406@vlnb.net> <20121025051445.GA9860@thunk.org> <20121025140325.49cd7c79@pyramind.ukuu.org.uk> <20121025135044.GA13562@thunk.org>
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Theodore Ts'o, on 10/25/2012 09:50 AM wrote:
> Yeah....  I don't buy that.  One, flash is still too expensive.  Two,
> the capital costs to build enough Silicon foundries to replace the
> current production volume of HDD's is way too expensive for any
> company to afford (the cloud providers are buying *huge* numbers of
> HDD's) --- and that's assuming companies wouldn't chose to use those
> foundries for products with larger margins --- such as, for example,
> CPU/GPU chips. :-) And third and finally, if you study the long-term
> trends in terms of Data Retention Time (going down), Program and Read
> Disturb (going up), and Write Endurance (going down) as a function of
> feature size and/or time, you'd be wise to treat flash as nothing more
> than short-term cache, and not as a long term stable store.
>
> If end users completely give up on flash, and store all of their
> precious family pictures on flash storage, after a couple of years,
> they are likely going to be very disappointed....
>
> Speaking personally, I wouldn't want to have anything on flash for
> more than a few months at *most* before I made sure I had another copy
> saved on spinning rust platters for long-term retention.

Here I agree with you.

Vlad
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