228 lines
8.9 KiB
HTML
228 lines
8.9 KiB
HTML
<!--startcut ======================================================= -->
|
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
|
|
<html>
|
|
<head>
|
|
<META NAME="generator" CONTENT="lgazmail v1.2M.b">
|
|
<TITLE>The Answer Guy 43: Arco Duplidisk: Disk Mirroring</TITLE>
|
|
</HEAD><BODY BGCOLOR="#FFFFFF" TEXT="#000000"
|
|
LINK="#3366FF" VLINK="#A000A0">
|
|
<!-- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -->
|
|
<H4>"The Linux Gazette...<I>making Linux just a little more fun!</I>"</H4>
|
|
<P> <hr> <P>
|
|
<!-- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -->
|
|
<center>
|
|
<H1><A NAME="answer">
|
|
<img src="../../gx/dennis/qbubble.gif" alt="(?)"
|
|
border="0" align="middle">
|
|
<font color="#B03060">The Answer Guy</font>
|
|
<img src="../../gx/dennis/bbubble.gif" alt="(!)"
|
|
border="0" align="middle">
|
|
</A></H1>
|
|
<BR>
|
|
<H4>By James T. Dennis,
|
|
<a href="mailto:linux-questions-only@ssc.com">linux-questions-only@ssc.com</a><BR>
|
|
LinuxCare,
|
|
<A HREF="http://www.linuxcare.com/">http://www.linuxcare.com/</A>
|
|
</H4>
|
|
</center>
|
|
|
|
<p><hr><p>
|
|
<!-- endcut ======================================================= -->
|
|
<!-- begin 10 -->
|
|
<H3 align="left"><img src="../../gx/dennis/qbubble.gif"
|
|
height="50" width="60" alt="(?) " border="0"
|
|
>Arco Duplidisk: Disk Mirroring</H3>
|
|
|
|
|
|
<p><strong>From Randy Kerr on Tue, 08 Jun 1999
|
|
</strong></p>
|
|
<!-- ::
|
|
Arco Duplidisk: Disk Mirroring
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
:: -->
|
|
<P><STRONG>
|
|
Hi Jim,
|
|
</STRONG></P>
|
|
<P><STRONG>
|
|
Not quite sure how to post a question to the 'Answer Guy'
|
|
and this seems to be the only option.
|
|
</STRONG></P>
|
|
<BLOCKQUOTE><IMG SRC="../../gx/dennis/bbub.gif" ALT="(!)"
|
|
HEIGHT="28" WIDTH="50" BORDER="0"
|
|
>
|
|
One of these days we should clarify that. The
|
|
address: <mailto: <A HREF="mailto:answerguy@linuxgazette.com"
|
|
>answerguy@linuxgazette.com</A>> should work,
|
|
as does <mailto: <A HREF="mailto:linux-questions-only@ssc.com"
|
|
>linux-questions-only@ssc.com</A>> and, of course my
|
|
home/personal address at starshine.org (deprecated).
|
|
</BLOCKQUOTE>
|
|
<P><STRONG><IMG SRC="../../gx/dennis/qbub.gif" ALT="(?)"
|
|
HEIGHT="28" WIDTH="50" BORDER="0"
|
|
>
|
|
I was wondering if you have had any experience or know of anyone
|
|
using Arco's DupliDisk for mirroring IDE drives. Wanted to know something
|
|
about reliability, ease of installation, etc. Specifically, if a hard disk
|
|
must be cloned prior to linking to its mate, or if the card mirrors the
|
|
entire drive upon installation.
|
|
</STRONG></P>
|
|
<P><STRONG>
|
|
Thanks a lot.
|
|
<br>Randy Kerr
|
|
</STRONG></P>
|
|
<BLOCKQUOTE><IMG SRC="../../gx/dennis/bbub.gif" ALT="(!)"
|
|
HEIGHT="28" WIDTH="50" BORDER="0"
|
|
>
|
|
I don't have any experience with these controllers.
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
However it should work. According to their FAQ
|
|
(<A HREF="http://www.arcoide.com/faq.htm"
|
|
>http://www.arcoide.com/faq.htm</A>):
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE><dl>
|
|
<dt>Q : Does the DupliDisk support Windows 95, 98 and NT?
|
|
<dd>A : Yes, the DupliDisk is a total hardware solution and will work
|
|
with any operating system--Windows 3.x, 95, 98 and NT, UNIX, LINUX,
|
|
BSDI, <A HREF="http://www.freebsd.org/">FreeBSD</A>, OS/2, Novell,
|
|
Solaris386--without the use of
|
|
</dl></BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
I have no idea regarding ease of use, reliability or any of
|
|
that. A web search on the phrase "Arco Duplidisk"
|
|
generates almost a 100 hits at Yahoo! including reviews
|
|
in Computerist Magazine (<A HREF="http://www.p3p.com"
|
|
>http://www.p3p.com</A>),
|
|
VAR Business (<A HREF="http://www.varbusiness.com"
|
|
>http://www.varbusiness.com</A>), Telephony
|
|
World (<A HREF="http://www.telephonyworld.com"
|
|
>http://www.telephonyworld.com</A>),
|
|
PC Today (<A HREF="http://www.pctoday.com"
|
|
>http://www.pctoday.com</A>) Medicine News
|
|
(<A HREF="http://www.medicine-news.com/articles/computer"
|
|
>http://www.medicine-news.com/articles/computer</A>)
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
Here are pointers to those reviews directly though I'm
|
|
no judge of their accuracy or value:
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE><dl>
|
|
<dt>Arco Announces New IDE Backup Device DupliDisk Makes Disk
|
|
Mirroring an Affordable Option
|
|
<DD><A HREF="http://www.p3p.com/news/10/arco.shtml"
|
|
>http://www.p3p.com/news/10/arco.shtml</A>
|
|
|
|
<DT>Arco Will Back You Up - VARBUSINESS - December 1996
|
|
<DD><A HREF="http://www.varbusiness.com/print-archive/19961201/1220varsh048.asp"
|
|
>http://www.varbusiness.com/print-archive/19961201/1220varsh048.asp</A>
|
|
|
|
<DT>Arco Announces New IDE Backup Device DupliDisk Makes Disk
|
|
Mirroring an Affordable Option
|
|
<DD><A HREF="http://www.telephonyworld.com/roundup/duplidisk.htm"
|
|
>http://www.telephonyworld.com/roundup/duplidisk.htm</A>
|
|
|
|
<DT>ARCO Computer,DupliDisk,medicine-news.com, Press Releases computer
|
|
hard- and software,
|
|
<DD><A HREF="http://www.medicine-news.com/articles/computer/arco98_1.html"
|
|
>http://www.medicine-news.com/articles/computer/arco98_1.html</A>
|
|
<DT>PC Today's Hard-Hitting Product Reviews
|
|
<DD><A HREF="http://www.pctoday.com/editorial/hardware/980416.html"
|
|
>http://www.pctoday.com/editorial/hardware/980416.html</A>
|
|
</DL>
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
In any event I'm not sure that the ~$200 you'd spend on one
|
|
of these would really net you much advantage over Linux
|
|
built-in md (multi-device) drivers (which implement
|
|
striping, mirroring and RAID 5 through software).
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
These devices don't do give any performance advantage over a
|
|
single disk drive (mentioned in their FAQ). Even the Linux
|
|
software driver gives <EM>some</EM> performance edge over single
|
|
disk (by interleaving read and write requests among the
|
|
available drives and resynching the devices asynchronously
|
|
through its caching mechanisms).
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
You should also consider the nature of the risks which the
|
|
Duplidisk addresses vs. the actual risk profiles that are
|
|
present. Duplidisk only protects you from a single drive
|
|
failure (per controller). It doesn't address accidental
|
|
deletion, damage due to software bugs (data corruption, etc)
|
|
or deliberate sabotage due to failures in your security
|
|
measures (including crackers, trojans, viruses, etc).
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
Drive failure is currently one of the less common causes of
|
|
data losss under Linux (although the rate of damage caused
|
|
by PC virus infection are probably even lower than disk
|
|
failure under Linux).
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
Overall, I think you're much better served by
|
|
using an extra hard drive (which you'd connect to Duplidisk)
|
|
and just perform nightly snapshots to it using 'cp -pax'
|
|
and or 'cpio -p' or 'tar cf ...' piped into a 'tar xf ...'
|
|
The "snapshot" method protects against several different
|
|
threats --- particularly that of accidental deletion; which
|
|
is the most common cause of data loss. (If you have a
|
|
'cron' job which makes your snapshots in the middle of the
|
|
night you'll usually have a half a day or so to realize that
|
|
you've accidentally removed or damaged some of them).
|
|
</BLOCKQUOTE>
|
|
<BLOCKQUOTE>
|
|
Personally I think that's a better way of spending your
|
|
money. (Heck, you can use the extra two hundred bucks to
|
|
put in a third drive --- and use a combination of md/RAID-1
|
|
--- mirroring across a pair of drives and using the third
|
|
for snapshots).
|
|
</BLOCKQUOTE>
|
|
<!-- sig -->
|
|
|
|
<!-- end 10 -->
|
|
<!--startcut ======================================================= -->
|
|
<P> <hr> <P>
|
|
<H5 align="center"><a href="http://www.linuxgazette.com/copying.html"
|
|
>Copyright ©</a> 1999, James T. Dennis
|
|
<BR>Published in <I>The Linux Gazette</I> Issue 43 July 1999</H5>
|
|
<H6 ALIGN="center">HTML transformation by
|
|
<A HREF="mailto:star@starshine.org">Heather Stern</a> of
|
|
Starshine Techinical Services,
|
|
<A HREF="http://www.starshine.org/">http://www.starshine.org/</A>
|
|
</H6>
|
|
<P> <hr> <P>
|
|
<!-- begin tagnav ::::::::::::::::::::::::::::::::::::::::::::::::::-->
|
|
<TABLE WIDTH="97%"><TR VALIGN="center" ALIGN="center">
|
|
<TD ROWSPAN="3" COLSPAN="1" WIDTH="40%"><A
|
|
HREF="../lg_answer43.html"
|
|
><IMG SRC="../../gx/dennis/answernew.gif"
|
|
ALT="[ Answer Guy Index ]"></A></td>
|
|
<TD WIDTH="19%"><A HREF="1.html">1</A></TD>
|
|
<TD WIDTH="19%"><A HREF="2.html">2</A></TD>
|
|
<TD WIDTH="19%"><A HREF="3.html">3</A></TD>
|
|
</TR><TR VALIGN="center" ALIGN="center">
|
|
<TD><A HREF="4.html">4</A></TD>
|
|
<TD><A HREF="5.html">5</A></TD>
|
|
<TD><A HREF="6.html">6</A></TD>
|
|
</TR><TR VALIGN="center" ALIGN="center">
|
|
<TD><A HREF="7.html">7</A></TD>
|
|
<TD><A HREF="8.html">8</A></TD>
|
|
<TD><A HREF="9.html">9</A></TD>
|
|
</TR></TABLE>
|
|
<!-- end tagnav ::::::::::::::::::::::::::::::::::::::::::::::::::::-->
|
|
<P> <hr> <P>
|
|
<!-- begin lgnav ::::::::::::::::::::::::::::::::::::::::::::::::::: -->
|
|
<A HREF="../index.html"
|
|
><IMG SRC="../../gx/indexnew.gif" ALT="[ Table Of Contents ]"></A>
|
|
<A HREF="/index.html"
|
|
><IMG SRC="../../gx/homenew.gif" ALT="[ Front Page ]"></A>
|
|
<A HREF="../lg_bytes43.html"
|
|
><IMG SRC="../../gx/back2.gif" ALT="[ Previous Section ]"></A>
|
|
<A HREF="../lg_tips43.html"
|
|
><IMG SRC="../../gx/fwd.gif" ALT="[ Next Section ]"></A>
|
|
<!-- end lgnav ::::::::::::::::::::::::::::::::::::::::::::::::::::: -->
|
|
<!-- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -->
|
|
</BODY></HTML>
|
|
<!--endcut ========================================================= -->
|