From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <gentoo-user+bounces-159525-garchives=archives.gentoo.org@lists.gentoo.org>
Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80])
by finch.gentoo.org (Postfix) with ESMTP id E2DE1138978
for <garchives@archives.gentoo.org>; Mon, 27 Oct 2014 15:23:31 +0000 (UTC)
Received: from pigeon.gentoo.org (localhost [127.0.0.1])
by pigeon.gentoo.org (Postfix) with SMTP id 1BB9DE09E8;
Mon, 27 Oct 2014 15:23:26 +0000 (UTC)
Received: from mail-wg0-f51.google.com (mail-wg0-f51.google.com [74.125.82.51])
(using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits))
(No client certificate requested)
by pigeon.gentoo.org (Postfix) with ESMTPS id C6900E09E0
for <gentoo-user@lists.gentoo.org>; Mon, 27 Oct 2014 15:23:24 +0000 (UTC)
Received: by mail-wg0-f51.google.com with SMTP id b13so5945420wgh.10
for <gentoo-user@lists.gentoo.org>; Mon, 27 Oct 2014 08:23:23 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=gmail.com; s=20120113;
h=from:reply-to:to:subject:date:user-agent:references:in-reply-to
:mime-version:content-type:content-transfer-encoding:message-id;
bh=vRkzdK2M+J5Y6DbnHnogBXDYbF8BXZnyNXTWr+aI1fo=;
b=TmLRd218Lv3vwlCcvUCvIEGzWesPG+ng5A98M0FcXlKs9yn10p61ALJW+GFM2kclwe
eBkK4qI1KSV+Jt1uAg5juaJ2XVwoUD7hXyay1QIzY3tMb7A5tma/P/mN5t/PDtaGpx/D
akAzZb2OkpsueBvkYZi2IkQ2X7GoND7JVMTxcanKSTuno1Ilf1c+FICit4100kEuFZ/U
ZZ2fUOczFSAjJJ4L4wD4fQrHqWknDuE7qlXysQGowv7zMbC9YkGopqLOJtzvwaFo72hG
dVmPETu6JjUyMwglEakNAn9aPvPA7VNahOPgY224UisxSm/Umat09V9EbXXw2gC0z13z
/h4g==
X-Received: by 10.180.87.196 with SMTP id ba4mr11778390wib.40.1414423403458;
Mon, 27 Oct 2014 08:23:23 -0700 (PDT)
Received: from dell_xps.localnet (230.3.169.217.in-addr.arpa. [217.169.3.230])
by mx.google.com with ESMTPSA id au3sm15952090wjc.15.2014.10.27.08.23.22
for <gentoo-user@lists.gentoo.org>
(version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128);
Mon, 27 Oct 2014 08:23:22 -0700 (PDT)
From: Mick <michaelkintzios@gmail.com>
To: gentoo-user@lists.gentoo.org
Subject: Re: [gentoo-user] Re: Safeguarding strategies against SSD data loss
Date: Mon, 27 Oct 2014 15:23:20 +0000
User-Agent: KMail/1.13.7 (Linux/3.16.5-gentoo; KDE/4.12.5; x86_64; ; )
References: <201410270924.40381.michaelkintzios@gmail.com> <CAGfcS_mbyhQ4hWW20h7g0WmR8Xx5iNVK1dFjSm=pcW9kNrcp4Q@mail.gmail.com> <loom.20141027T154955-641@post.gmane.org>
In-Reply-To: <loom.20141027T154955-641@post.gmane.org>
Precedence: bulk
List-Post: <mailto:gentoo-user@lists.gentoo.org>
List-Help: <mailto:gentoo-user+help@lists.gentoo.org>
List-Unsubscribe: <mailto:gentoo-user+unsubscribe@lists.gentoo.org>
List-Subscribe: <mailto:gentoo-user+subscribe@lists.gentoo.org>
List-Id: Gentoo Linux mail <gentoo-user.gentoo.org>
X-BeenThere: gentoo-user@lists.gentoo.org
Reply-to: gentoo-user@lists.gentoo.org
MIME-Version: 1.0
Content-Type: multipart/signed;
boundary="nextPart1434213.1cOiNg6g04";
protocol="application/pgp-signature";
micalg=pgp-sha256
Content-Transfer-Encoding: 7bit
Message-Id: <201410271523.22392.michaelkintzios@gmail.com>
X-Archives-Salt: ef48543e-e1c6-4ed0-ada1-62c4c1e0cbe9
X-Archives-Hash: d82754dc73d5ef183a211f5418fec86d
--nextPart1434213.1cOiNg6g04
Content-Type: Text/Plain;
charset="utf-8"
Content-Transfer-Encoding: quoted-printable
On Monday 27 Oct 2014 15:15:22 James wrote:
> Rich Freeman <rich0 <at> gentoo.org> writes:
> > > On 27/10/2014 11:24, Mick wrote:
> > >>> With a caveat: if an ssd dies, it will die suddenly. Without warnin=
g.
>=20
> With SSD the most important fact to keep constantly in mind is
> writing/erasing by blocks due to uniqueness of the hardware.
> Unfortunately, if you dig deeply, many Solid State Storage devices
> are organized differently and those hardware differences may impact
> your SSD_specific implementation details. SSD raid redundancy is
> something most machines (folks) cannot afford, imho and may be a waist
> to dis_functional if you employ the same semantics for I/O on the
> redundant SSD hardware.
>=20
> [1]
> http://codecapsule.com/2014/02/12/coding-for-ssds-part-6-a-summary-what-e=
ve
> ry-programmer-should-know-about-solid-state-drives/
>=20
> > >> In such cases I am prepared to live with the risk of some
> > >>=20
> > >> data loss, on machines where raid is not an option.
>=20
> Wise with a well thought out (planned) recovery/fresh-install strategy.
>=20
> > > Without some form of redundancy that would be your best strategy -
> > > decent and frequent backups
> >=20
> > But yes, backup and RAID are really your only options for SSD failure
> > as far as I can see it. That and limiting the amount of data that
> > can't be re-generated. If you just save the world file and all of
> > /etc you could probably rebuild a Gentoo install fairly quickly on a
> > new drive, and then you're just left with /home and whatever else you
> > happen to have installed that sticks stuff in /var that you care
> > about.
>=20
> Yep. Rich has it exactly right. I'd add /usr/local/*
> as by design that is where I put most uniqueness in any linux system
> besides the list above.
>=20
> In fact for small networks, I just identify the directories that I want
> to preserve. At the least you rsysnc those to a differnet system
> on the local net, besides a backup, if no raid is underneath. (Triple).
> Obviously, you have all systems on UPS power......?
>=20
> I'd add any dirs with custom scripts and the kernel files also minimally
> replicated to another system. A comprehensive list of critical files
> is fine. Workstations and servers have different lists of critial files;
> and you can further subdivide the servers by function, to focus
> on those critical files and directories. So what is on the SSD that is
> important, just replicate it to a spinning HD on the local net. None
> of this replaces weekly backups, but give you a tertiary level of
> recovery redundancy for the important stuff. Triple redundancy is keenly
> important for all critical stuff; ymmv.
>=20
> Personally, I find max-ram and spinning HD to be the best bang for the
> buck. But, many folks with older portables are usually really happy with
> SSD as a replacement (single) drive that is cost effective but needs
> a network backup.
>=20
> [2]
> http://serverfault.com/questions/454775/is-post-sudden-power-loss-filesys=
te
> m-corruption-on-an-ssd-drives-ext3-partition
>=20
>=20
> hth,
> James
Good comments and links James. Thank you.
=2D-=20
Regards,
Mick
--nextPart1434213.1cOiNg6g04
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
iQEcBAABCAAGBQJUTmNqAAoJELAdA+zwE4YeCtkIAM22adx2QX02pkBfjTlENrD0
L8rYbjDz+h0bCIYlrww81scsYG3vZ2QfU8+xLj492df5UbFO2HIA/++UDnZcpnQW
BXHnN0BFjzVJyKo2K6InGsWNDv+FDnfV+pi4QdKoAoSsb/sDJ7153ZMX7FoCcCna
5AG1x/hD7AJlcWpbPd+i0qde15FAcaz9nUiTSM0K95yLHuexBB3we+qY44rj46hk
nszCUZfxePW8osVR1q0Yl2deT0fc4acNfuR3g1bMJgMfAr7Edr4Sn+kWfMXZHaSA
Ld0V4FJG70HP21h5NJeC4dj7M9cgV12KD8FcJ+jlmP8Agzaoxi4dZpOBgOs6XJc=
=2qAI
-----END PGP SIGNATURE-----
--nextPart1434213.1cOiNg6g04--