Gentoo Archives: gentoo-user

From: Grant <emailgrant@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] {OT} SSD instead of RAID1?
Date: Thu, 30 Jul 2009 12:53:31
Message-Id: 49bf44f10907300553k520bd60cr1c8105b10ef0b35d@mail.gmail.com
In Reply to: Re: [gentoo-user] {OT} SSD instead of RAID1? by Neil Bothwick
1 >> Anyway, the point of all this is to prevent an HD failure from
2 >> stopping the system.  An SSD is much safer, right?
3 >
4 > SSDs are still relatively new technology, so predicting failure rates is
5 > less reliable. What's wrong with using RAID-1? It's proven technology and
6 > totally resistant to a single HD failure.
7
8 Well, I've read great things about the reliability of SSDs. Here's a
9 comment from Samsung:
10
11 http://www.engadget.com/2008/02/23/samsung-puts-the-kibosh-on-ssd-reliability-worries/
12
13 "a pattern could be perpetually repeated in which a 64GB SSD is
14 completely filled with data, erased, filled again, then erased again
15 every hour of every day for years, and the user still wouldn't reach
16 the theoretical write limit"
17
18 So in theory, the things are very reliable, but we wonder how they do
19 in the real world.
20
21 I'm considering a Super Talent Ultradrive which uses the relatively
22 new Indilinx controller. There are 60 reviews of these drives on
23 newegg.com. Of these 60, there are only 2 reports of operational
24 problems, most of the remainder are glowing tales of speed and
25 silence. This is a "cheap" drive using technology that is new even
26 for an SSD, and still the newegg.com reports aren't dominated by
27 reports of "DOA!" or "Failed within 1 week!" like all of the
28 newegg.com HD reports I've seen. Of course, this is far from
29 empirical evidence of SSD reliability, but it's very encouraging.
30
31 I shy away from RAID1 for a few reasons. I posted these a little while ago:
32
33 1. RAID is another layer to learn, install, and maintain.
34
35 2. RAID isn't foolproof:
36
37 http://hardware.slashdot.org/article.pl?sid=08/10/21/2126252&from=rss
38 http://blogs.zdnet.com/storage/?p=162
39
40 3. RAID is relatively expensive on a hosted server. Let's assume that
41 without RAID, the hard drive in use fails every 3 years and causes 24
42 hours of downtime with good backups. That's a loss of .09% uptime
43 over 3 years. If the server makes $100,000/year (and the same amount
44 every day), that's a loss of $273 over 3 years. However, my host
45 wants $105/month for a second 15k hard drive and RAID controller card.
46 The cost of that over 3 years is $3,780.
47
48 - Grant