177 lines
11 KiB
HTML
177 lines
11 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 lang="en-us" xml:lang="en-us">
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<meta name="security" content="public" />
|
|
<meta name="Robots" content="index,follow" />
|
|
<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
|
|
<meta name="DC.Type" content="concept" />
|
|
<meta name="DC.Title" content="Save-while-active function" />
|
|
<meta name="DC.Relation" scheme="URI" content="rzaiurzaiu311.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rzaiurzaiu327.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rzaiurzaiu328.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rzaiucommitoverview.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rzaiurzaiu314.htm" />
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 2004, 2006" />
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2004, 2006" />
|
|
<meta name="DC.Format" content="XHTML" />
|
|
<meta name="DC.Identifier" content="rzaiu310" />
|
|
<meta name="DC.Language" content="en-us" />
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
|
<!-- US Government Users Restricted Rights -->
|
|
<!-- Use, duplication or disclosure restricted by -->
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
|
<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
|
|
<link rel="stylesheet" type="text/css" href="./ic.css" />
|
|
<title>Save-while-active function</title>
|
|
</head>
|
|
<body id="rzaiu310"><a name="rzaiu310"><!-- --></a>
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
|
<h1 class="topictitle1">Save-while-active function</h1>
|
|
<div><p>The save-while-active function is an option on several i5/OS™ save commands.
|
|
It allows you to save parts of your server without putting your server in
|
|
a restricted state. You can use the save-while-active function to reduce your
|
|
save outage or to eliminate your save outage.</p>
|
|
</div>
|
|
<div>
|
|
<ul class="ullinks">
|
|
<li class="ulchildlink"><strong><a href="rzaiurzaiu327.htm">Checkpoint processing with save-while-active</a></strong><br />
|
|
</li>
|
|
<li class="ulchildlink"><strong><a href="rzaiurzaiu328.htm">Timestamp processing with save-while-active</a></strong><br />
|
|
</li>
|
|
<li class="ulchildlink"><strong><a href="rzaiucommitoverview.htm">Commitment control with save-while-active</a></strong><br />
|
|
</li>
|
|
</ul>
|
|
|
|
<div class="familylinks">
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzaiurzaiu311.htm" title="How your save-while-active function fits into your backup and recovery strategy depends on whether you will reduce or eliminate your save-outage time. These pages contain information to help you decide how you will use the save-while-active function. It also contains pages with technical descriptions of the save-while-active function.">Save-while-active and your backup and recovery strategy</a></div>
|
|
</div>
|
|
<div class="relconcepts"><strong>Related concepts</strong><br />
|
|
<div><a href="rzaiurzaiu314.htm">Save-while-active restrictions</a></div>
|
|
</div>
|
|
</div><div class="nested1" xml:lang="en-us" id="howitworks"><a name="howitworks"><!-- --></a><h2 class="topictitle2">How it works</h2>
|
|
<div><p id="howitworks__rzaiju326"><a name="howitworks__rzaiju326"><!-- --></a>i5/OS objects consist of units of storage, which are
|
|
called <span class="uicontrol">pages</span>. When you use the save-while-active function
|
|
to save an object, the server creates two images of the pages of the object:</p>
|
|
<ul><li>The first image contains the updates to the object with which normal server
|
|
activity works.</li>
|
|
<li>The second image is an image of the object at a single point in time.
|
|
The save-while-active job uses this image to save the object to the media.</li>
|
|
</ul>
|
|
<p>In other words, when an application makes changes to an object during a
|
|
save-while-active job, the server uses one image of the object's pages to
|
|
make the changes. At the same time, the server uses the other image to save
|
|
the object to the media. The image that the server saves does not have the
|
|
changes you made during the save-while-active job. The image on the media
|
|
is as it existed when the server reached a checkpoint.</p>
|
|
</div>
|
|
</div>
|
|
<div class="nested1" xml:lang="en-us" id="checkpoints"><a name="checkpoints"><!-- --></a><h2 class="topictitle2">Checkpoints</h2>
|
|
<div><p> The <span class="uicontrol">checkpoint</span> for an object is the instant in
|
|
time that the server creates an image of that object. The image that the server
|
|
creates at that instant in time is the <span class="uicontrol">checkpoint image</span> of
|
|
the object. </p>
|
|
<p>Creating a checkpoint image is similar to taking a photograph of a moving
|
|
automobile. The point in time that you took the photograph would equate to
|
|
the checkpoint. The photograph of the moving automobile would equate to the
|
|
checkpoint image. When the server has finished making the checkpoint image
|
|
of the object, the object has reached a checkpoint.</p>
|
|
<p>Despite the name save-while-active, you cannot change objects while the
|
|
server obtains their checkpoint images. The server allocates (or locks) objects
|
|
as it obtains checkpoint images. After the server obtains the checkpoint images,
|
|
you can change the objects.</p>
|
|
</div>
|
|
</div>
|
|
<div class="nested1" xml:lang="en-us" id="synchronization"><a name="synchronization"><!-- --></a><h2 class="topictitle2">Synchronization</h2>
|
|
<div><p>When you save more than one object, you must choose when the objects will
|
|
reach a checkpoint in relationship to each other. This is synchronization.
|
|
There are three kinds of synchronization: </p>
|
|
<ul><li><span class="uicontrol">Full synchronization</span>With full synchronization,
|
|
the checkpoints for all of the objects occur at the same time. The checkpoints
|
|
occur during a time period in which no changes can occur to the objects. IBM<sup>®</sup> strongly
|
|
recommends that you use full synchronization, even when you are saving objects
|
|
in only one library. </li>
|
|
<li><span class="uicontrol">Library synchronization</span>With library synchronization,
|
|
the checkpoints for all of the objects in a library occur at the same time. <p></p>
|
|
</li>
|
|
<li><span class="uicontrol">System-defined synchronization</span>With system-defined
|
|
synchronization, the server decides when the checkpoints for the objects occur.
|
|
The checkpoints for the objects may occur at different times resulting in
|
|
complex restore procedures. </li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="nested1" xml:lang="en-us" id="save-outagetime"><a name="save-outagetime"><!-- --></a><h2 class="topictitle2">Save-outage time</h2>
|
|
<div><p>The amount of time during the backup process that you cannot use the server
|
|
is the <span class="uicontrol">save-outage time</span>. You can use the save-while-active
|
|
function to <span class="uicontrol">reduce</span> or <span class="uicontrol">eliminate</span> your
|
|
save outage. </p>
|
|
<p>The easiest and recommended way to use the save-while-active function is
|
|
to <span class="uicontrol">reduce</span> your save-outage time. You can reduce your
|
|
save-outage time by ending your applications that change objects. You can
|
|
restart the applications after the server has reached a checkpoint for those
|
|
objects. You can choose to have the save-while-active function send a notification
|
|
when it completes the <a href="rzaiurzaiu327.htm#rzaiu327">checkpoint
|
|
processing</a>. After the save-while-active function completes checkpoint
|
|
processing, it is safe to start your applications again. When you use the
|
|
save-while-active function in this way, the save-outage time can be much less
|
|
than with normal save operations.</p>
|
|
<p>You can also use the save-while-active function to <span class="uicontrol">eliminate</span> your
|
|
save-outage time. When you use the save-while-active function to eliminate
|
|
your save-outage time, you do not end the applications that make changes to
|
|
the objects you save. However, the save operation affects the performance
|
|
and response time of your applications. You should also use journaling or
|
|
commitment control for all of the objects you are saving when using save-while-active
|
|
in this way. Using the save-while-active function to eliminate your save-outage
|
|
time may also greatly increase the complexity of your recovery procedures.</p>
|
|
</div>
|
|
</div>
|
|
<div class="nested1" xml:lang="en-us" id="save-while-activecommands"><a name="save-while-activecommands"><!-- --></a><h2 class="topictitle2">Save-while-active commands</h2>
|
|
<div><p>The save-while-active function is an option on the i5/OS save commands listed below:</p>
|
|
|
|
<div class="tablenoborder"><table cellpadding="4" cellspacing="0" summary="" frame="border" border="1" rules="all"><thead align="left"><tr><th valign="top" width="50%" id="d0e139">Command</th>
|
|
<th valign="top" width="50%" id="d0e141">Function</th>
|
|
</tr>
|
|
</thead>
|
|
<tbody><tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVLIB</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save Library</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVOBJ</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save Object</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVCHGOBJ</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save Changed Objects</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVDLO</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save Document Library
|
|
Objects</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAV</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVRSTLIB</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save/Restore Library</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVRSTOBJ</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save/Restore Object</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVRSTCHG</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save/Restore Changed Objects</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVRSTDLO</td>
|
|
<td align="left" valign="top" width="50%" headers="d0e141 ">Save/Restore Document
|
|
Library Objects</td>
|
|
</tr>
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e139 ">SAVRST</td>
|
|
<td valign="top" width="50%" headers="d0e141 ">Save/Restore</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
|
|
</body>
|
|
</html> |