191 lines
9.0 KiB
HTML
191 lines
9.0 KiB
HTML
<?xml version="1.0" encoding="utf-8"?>
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|
<html xml:lang="en" lang="en" xmlns="http://www.w3.org/1999/xhtml">
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
|
|
<meta http-equiv="Content-Style-Type" content="text/css" />
|
|
<title>About Degraded Units</title>
|
|
<link rel="StyleSheet" href="css/Maintain_Units.css" type="text/css" media="all" />
|
|
<link rel="StyleSheet" href="css/webworks.css" type="text/css" media="all" />
|
|
<script type="text/javascript" language="JavaScript1.2" src="scripts/expand.js"></script>
|
|
<script type="text/javascript" language="JavaScript1.2" src="scripts/seealso.js"></script>
|
|
<script type="text/javascript" language="JavaScript1.2">
|
|
<!--
|
|
var WebWorksRootPath = "";
|
|
// -->
|
|
</script>
|
|
<script type="text/javascript" language="JavaScript1.2">
|
|
<!--
|
|
var WebWorksSeeAlso = "xxx";
|
|
// -->
|
|
</script>
|
|
</head>
|
|
<body style="">
|
|
<table align="right">
|
|
<tr>
|
|
<td style="text-align: left;">
|
|
<a href="http://www.lsi.com/channel/products" target="_blank">
|
|
<img src="LSI-logo.jpg" border="0" />
|
|
</a>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
<div style="text-align: left;">
|
|
<p style="color: Navy; font-weight:bold">3DM2™ Online
|
|
Help</p>
|
|
<table cellspacing="0">
|
|
<tr>
|
|
<td>
|
|
<a href="toc.html">
|
|
<img src="images/toc.gif" alt="Table of Contents" border="0" />
|
|
</a>
|
|
</td>
|
|
<td>
|
|
<a href="Maintain_Units.7.6.html">
|
|
<img src="images/prev.gif" alt="Previous" border="0" />
|
|
</a>
|
|
</td>
|
|
<td>
|
|
<a href="Maintain_Units.7.8.html">
|
|
<img src="images/next.gif" alt="Next" border="0" />
|
|
</a>
|
|
</td>
|
|
<td>
|
|
<a href="ix.html">
|
|
<img src="images/index.gif" alt="Index" border="0" />
|
|
</a>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<br clear="all" />
|
|
<br />
|
|
<div class="WebWorks_Breadcrumbs" style="text-align: left;">
|
|
<a class="WebWorks_Breadcrumb_Link" href="Maintain_Units.7.1.html#1145155">Maintaining Units</a> > About Degraded Units</div>
|
|
<hr align="left" />
|
|
<div>
|
|
<div class="Heading1"><a name="1145155">About Degraded Units</a></div>
|
|
<div class="Body"><a name="1169358">Fault-tolerant RAID units provide data redundancy by duplicating </a>information on multiple drives. These RAID units make it possible to continue use even if one of the drives in the unit has failed. </div>
|
|
<div class="Bullet_outer" style="margin-left: NaN;">
|
|
<table border="0" cellspacing="0" cellpadding="0" id="SummaryNotRequired_np1169359">
|
|
<tr style="vertical-align: baseline;">
|
|
<td>
|
|
<div class="Bullet_inner" style="width: 1.5em; white-space: nowrap;">
|
|
<img src="sqbullet.gif" alt="*" id="bullet1169359" border="0" width="8" height="8" />
|
|
</div>
|
|
</td>
|
|
<td width="100%">
|
|
<div class="Bullet_inner"><a name="1169359">RAID 1 and RAID 10 units each use mirroring to achieve fault tolerance. </a>Identical data is stored on two or more drives to protect against drive failure.</div>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="Bullet_outer" style="margin-left: NaN;">
|
|
<table border="0" cellspacing="0" cellpadding="0" id="SummaryNotRequired_np1431585">
|
|
<tr style="vertical-align: baseline;">
|
|
<td>
|
|
<div class="Bullet_inner" style="width: 1.5em; white-space: nowrap;">
|
|
<img src="sqbullet.gif" alt="*" id="bullet1431585" border="0" width="8" height="8" />
|
|
</div>
|
|
</td>
|
|
<td width="100%">
|
|
<div class="Bullet_inner"><a name="1431585">RAID 5, RAID 6, and RAID 50 units achieve fault tolerance by using a </a>simple (exclusive OR) function to generate the parity data that is distributed on all drives. </div>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="Bullet_outer" style="margin-left: NaN;">
|
|
<table border="0" cellspacing="0" cellpadding="0" id="SummaryNotRequired_np1431590">
|
|
<tr style="vertical-align: baseline;">
|
|
<td>
|
|
<div class="Bullet_inner" style="width: 1.5em; white-space: nowrap;">
|
|
<img src="sqbullet.gif" alt="*" id="bullet1431590" border="0" width="8" height="8" />
|
|
</div>
|
|
</td>
|
|
<td width="100%">
|
|
<div class="Bullet_inner"><a name="1431590">RAID 6 adds an extra level of protection over RAID 5 by generating a </a>second parity when data is written. This allows two drives to fail without compromising data integrity, especially on larger units. </div>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="Body"><a name="1322640">When one of the drives in a fault-tolerant unit fails or is removed or </a>unplugged, the unit is said to be <span class="Emphasis">degraded</span>. </div>
|
|
<div class="Body"><a name="1169383">You can still read and write data from a degraded unit, but the unit will not be </a>fault tolerant until it is rebuilt using the Rebuild feature. </div>
|
|
<div class="Body"><a name="1363321">When a RAID unit becomes degraded, it is marked as such, and the drive(s) </a>that failed are marked as <span class="UI-Element">Degraded</span> in the 3DM2 pages. If supported by your enclosure, the LED for failed drives may turn red.</div>
|
|
<div class="Body"><a name="1170795">You should replace the failed drive and rebuild the unit as soon as it is </a>convenient to do so. The unit will not be fault tolerant until it has been rebuilt. Rebuilding can occur automatically, depending on your settings. For more information, see <a href="Maintain_Units.7.20.html#1353024">Rebuilding Units</a>. </div>
|
|
<hr />
|
|
<dl>
|
|
<dt>Related Topics</dt>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.2.html#1080998" name="1675214">Checking Unit and Drive Status</a></div>
|
|
</dd>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.4.html#1486727" name="1675218">Enclosure Drive LED Status Indicators</a></div>
|
|
</dd>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.5.html#1251822" name="1675222">Unit Statuses</a></div>
|
|
</dd>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.6.html#1145546" name="1675226">Drive Statuses</a></div>
|
|
</dd>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.11.html#1304943" name="1675230">Viewing Alarms, Errors, and Other Events</a></div>
|
|
</dd>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.13.html#1136387" name="1675234">Downloading an Error Log</a></div>
|
|
</dd>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.14.html#1079505" name="1675238">Viewing SMART Data About a Drive</a></div>
|
|
</dd>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.8.html#1258376" name="1675242">About Inoperable Units</a></div>
|
|
</dd>
|
|
<dd>
|
|
<div class="RelatedTopic"><a href="Maintain_Units.7.20.html#1353024" name="1675246">Rebuilding Units</a></div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<hr align="left" />
|
|
<div style="text-align: left;">
|
|
<table cellspacing="0">
|
|
<tr>
|
|
<td>
|
|
<a href="toc.html">
|
|
<img src="images/toc.gif" alt="Table of Contents" border="0" />
|
|
</a>
|
|
</td>
|
|
<td>
|
|
<a href="Maintain_Units.7.6.html">
|
|
<img src="images/prev.gif" alt="Previous" border="0" />
|
|
</a>
|
|
</td>
|
|
<td>
|
|
<a href="Maintain_Units.7.8.html">
|
|
<img src="images/next.gif" alt="Next" border="0" />
|
|
</a>
|
|
</td>
|
|
<td>
|
|
<a href="ix.html">
|
|
<img src="images/index.gif" alt="Index" border="0" />
|
|
</a>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<table align="right">
|
|
<tr>
|
|
<td style="text-align: left;">
|
|
<a href="http://www.lsi.com/channel/products" target="_blank">
|
|
<img src="LSI-logo.jpg" border="0" />
|
|
</a>
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td style="text-align: left; font-size: 16px ; font-weight: bold">
|
|
<a href="http://www.lsi.com/channel/products" target="_blank">LSI Corporation</a>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
<p style="font-size: .8em">Copyright LSI 2004-2010<br />
|
|
To contact Support, go to <a href="http://www.lsi.com/channel/ContactUs">http://www.lsi.com/channel/ContactUs</a></p>
|
|
</body>
|
|
</html> |