1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>DB_ENV->backup()</title>
<link rel="stylesheet" href="apiReference.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
<link rel="start" href="index.html" title="Berkeley DB C API Reference" />
<link rel="up" href="env.html" title="Chapter 5. The DB_ENV Handle" />
<link rel="prev" href="envadd_data_dir.html" title="DB_ENV->add_data_dir()" />
<link rel="next" href="envclose.html" title="DB_ENV->close()" />
</head>
<body>
<div xmlns="" class="navheader">
<div class="libver">
<p>Library Version 12.1.6.1</p>
</div>
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">DB_ENV->backup()</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="envadd_data_dir.html">Prev</a> </td>
<th width="60%" align="center">Chapter 5.
The DB_ENV Handle
</th>
<td width="20%" align="right"> <a accesskey="n" href="envclose.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="envbackup"></a>DB_ENV->backup()</h2>
</div>
</div>
</div>
<pre class="programlisting">#include <db.h>
int
DB_ENV->backup(DB_ENV *dbenv, const char *target, u_int32_t flags); </pre>
<p>
The <code class="methodname">DB_ENV->backup()</code> method performs a hot
backup of the open environment. All files used by the environment
are backed up, so long as the normal rules for file placement are
followed. For information on how files are normally placed relative
to the environment directory, see
<a href="../../programmer_reference/env_naming.html" class="olink">Berkeley DB File Naming</a> in the <em class="citetitle">Berkeley DB Programmer's Reference Guide</em>.
</p>
<p>
By default, data directories and the log directory specified
relative to the home directory will be recreated relative to the
target directory. If absolute path names are used, then specify
<code class="literal">DB_BACKUP_SINGLE_DIR</code> to the <code class="literal">flags</code>
parameter.
</p>
<p>
This method provides the same functionality as the
<a class="xref" href="db_hotbackup.html" title="db_hotbackup">db_hotbackup</a>
utility. However, this method does not perform the housekeeping
actions performed by the <code class="literal">db_hotbackup</code> utility.
In particular, you may want to run a checkpoint before calling this
method. To run a checkpoint, use the
<a class="xref" href="txncheckpoint.html" title="DB_ENV->txn_checkpoint()">DB_ENV->txn_checkpoint()</a>
method. For more information on checkpoints, see
<a href="../../programmer_reference/transapp_checkpoint.html" class="olink">Checkpoints</a> in the <em class="citetitle">Berkeley DB Programmer's Reference Guide</em>.
</p>
<p>
To back up a single database file contained within the environment,
use the
<a class="xref" href="envdbbackup.html" title="DB_ENV->dbbackup()">DB_ENV->dbbackup()</a>
method.
</p>
<p>
This method's default behavior can be changed by setting backup
callbacks. See
<a class="xref" href="envset_backup_callbacks.html" title="DB_ENV->set_backup_callbacks()">DB_ENV->set_backup_callbacks()</a>
for more information. Additional tuning parameters can also be set
using the
<a class="xref" href="envset_backup_config.html" title="DB_ENV->set_backup_config()">DB_ENV->set_backup_config()</a> method.
</p>
<p>
The <code class="methodname">DB_ENV->backup()</code> method may only be
called after the environment handle has been opened.
</p>
<p>
The <code class="methodname">DB_ENV->backup()</code> <span>
<span>
method returns a non-zero error value on failure and 0 on success.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp827648"></a>Parameters</h3>
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp859696"></a>target</h4>
</div>
</div>
</div>
<p>
Identifies the directory in which the back up will be
placed. Any subdirectories required to contain the backup
must be placed relative to this directory. Note that if
the backup callbacks are set, then the value specified to
this parameter is passed on to the <code class="literal">open_func()</code>
callback. If this parameter is NULL, then the target must
be specified to the <code class="literal">open_func()</code>
callback.
</p>
<p>
This directory, and any required subdirectories, will be
created for you if you specify the
<code class="literal">DB_CREATE</code> flag on the call to this
method. Otherwise, if the target does not exist, this
method exits with an <code class="literal">ENOENT</code>
error return.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp867360"></a>flags</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>flags</strong></span> parameter must
be set to 0 or by bitwise inclusively
<span class="bold"><strong>OR</strong></span>'ing together one or more of
the values:
</p>
<div class="itemizedlist">
<ul type="disc">
<li>
<p>
<code class="literal">DB_BACKUP_CLEAN</code>
</p>
<p>
Before performing the backup, first remove all
files from the target backup directory tree.
</p>
</li>
<li>
<p>
<code class="literal">DB_BACKUP_FILES</code>
</p>
<p>
Back up all ordinary files that might exist in the
environment, and the environment's subdirectories.
</p>
</li>
<li>
<p>
<code class="literal">DB_BACKUP_NO_LOGS</code>
</p>
<p>
Back up only the <code class="literal">*.db</code>
files. Do not backup the log files.
</p>
</li>
<li>
<p>
<code class="literal">DB_BACKUP_SINGLE_DIR</code>
</p>
<p>
Regardless of the directory structure used by the
source environment, place all back up files in the
single directory identified by the
<code class="literal">target</code> parameter. Use this
option if absolute path names to your environment
directory and the files within that directory are
required by your application.
</p>
</li>
<li>
<p>
<code class="literal">DB_BACKUP_UPDATE</code>
</p>
<p>
Perform an incremental back up, instead of a full
back up. When this option is specified, only log
files are copied to the target directory.
</p>
</li>
<li>
<p>
<code class="literal">DB_CREATE</code>
</p>
<p>
If the target directory does not exist, create it
and any required subdirectories.
</p>
</li>
<li>
<p>
<code class="literal">DB_EXCL</code>
</p>
<p>
Return an <code class="literal">EEXIST</code> error if a
target backup file already exists.
</p>
</li>
<li>
<p>
<code class="literal">DB_VERB_BACKUP</code>
</p>
<p>
Run in verbose mode, listing operations as they are
completed.
</p>
</li>
</ul>
</div>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp898592"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">DB_ENV->backup()</code> <span>
<span>
method may fail and return one of the following non-zero errors:
</span>
</span>
</p>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp895760"></a>EEXIST</h4>
</div>
</div>
</div>
<p>
<code class="literal">DB_EXCL</code> was specified for the
<code class="literal">flags</code> parameter, and an existing target
file was discovered when attempting to back up a source
file.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp884544"></a>ENOENT</h4>
</div>
</div>
</div>
<p>
The target directory does not exist and <code class="literal">DB_CREATE</code>
was not specified for the <code class="literal">flags</code>
parameter.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp902824"></a>EINVAL</h4>
</div>
</div>
</div>
<p>
An invalid flag value or parameter was specified.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp904344"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp895392"></a>See Also</h3>
</div>
</div>
</div>
<p>
<a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a>
</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="envadd_data_dir.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="env.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="envclose.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">DB_ENV->add_data_dir() </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> DB_ENV->close()</td>
</tr>
</table>
</div>
</body>
</html>
|
