1INNOCHECKSUM(1) MySQL Database System INNOCHECKSUM(1)
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6 innochecksum - offline InnoDB file checksum utility
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9 innochecksum [options] file_name
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12 innochecksum prints checksums for InnoDB files. This tool reads an
13 InnoDB tablespace file, calculates the checksum for each page, compares
14 the calculated checksum to the stored checksum, and reports mismatches,
15 which indicate damaged pages. It was originally developed to speed up
16 verifying the integrity of tablespace files after power outages but can
17 also be used after file copies. Because checksum mismatches cause
18 InnoDB to deliberately shut down a running server, it may be preferable
19 to use this tool rather than waiting for an in-production server to
20 encounter the damaged pages.
21 innochecksum cannot be used on tablespace files that the server already
23 has open. For such files, you should use CHECK TABLE to check tables
24 within the tablespace. Attempting to run innochecksum on a tablespace
25 that the server already has open will result in an “Unable to lock
26 file” error.
27 If checksum mismatches are found, you would normally restore the
29 tablespace from backup or start the server and attempt to use mysqldump
30 to make a backup of the tables within the tablespace.
31 Invoke innochecksum like this:
33 shell> innochecksum [options] file_name
35 innochecksum Options.PP innochecksum supports the following options.
37 For options that refer to page numbers, the numbers are zero-based.
38 · --help, -?
40 Displays command line help. Example usage:
42 shell> innochecksum --help
44 · --info, -I
46 Synonym for --help. Displays command line help. Example usage:
48 shell> innochecksum --info
50 · --version, -V
52 Displays version information. Example usage:
54 shell> innochecksum --version
56 · --verbose, -v
58 Verbose mode; prints a progress indicator to the log file every
60 five seconds. In order for the progress indicator to be printed,
61 the log file must be specified using the --log option. To turn on
62 verbose mode, run:
63 shell> innochecksum --verbose
65 To turn off verbose mode, run:
67 shell> innochecksum --verbose=FALSE
69 The --verbose option and --log option can be specified at the same
71 time. For example:
72 shell> innochecksum --verbose --log=/var/lib/mysql/test/logtest.txt
74 To locate the progress indicator information in the log file, you
76 can perform the following search:
77 shell> cat ./logtest.txt | grep -i "okay"
79 The progress indicator information in the log file appears similar
81 to the following:
82 page 1663 okay: 2.863% done
84 page 8447 okay: 14.537% done
85 page 13695 okay: 23.568% done
86 page 18815 okay: 32.379% done
87 page 23039 okay: 39.648% done
88 page 28351 okay: 48.789% done
89 page 33023 okay: 56.828% done
90 page 37951 okay: 65.308% done
91 page 44095 okay: 75.881% done
92 page 49407 okay: 85.022% done
93 page 54463 okay: 93.722% done
94 ...
95 · --count, -c
97 Print a count of the number of pages in the file and exit. Example
99 usage:
100 shell> innochecksum --count ../data/test/tab1.ibd
102 · --start-page=num, -s num
104 Start at this page number. Example usage:
106 shell> innochecksum --start-page=600 ../data/test/tab1.ibd
108 or:
110 shell> innochecksum -s 600 ../data/test/tab1.ibd
112 · --end-page=num, -e num
114 End at this page number. Example usage:
116 shell> innochecksum --end-page=700 ../data/test/tab1.ibd
118 or:
120 shell> innochecksum --p 700 ../data/test/tab1.ibd
122 · --page=num, -p num
124 Check only this page number. Example usage:
126 shell> innochecksum --page=701 ../data/test/tab1.ibd
128 · --strict-check, -C
130 Specify a strict checksum algorithm. Options include innodb, crc32,
132 and none.
133 In this example, the innodb checksum algorithm is specified:
135 shell> innochecksum --strict-check=innodb ../data/test/tab1.ibd
137 In this example, the crc32 checksum algorithm is specified:
139 shell> innochecksum -C crc32 ../data/test/tab1.ibd
141 The following conditions apply:
143 · If you do not specify the --strict-check option, innochecksum
145 validates against innodb, crc32 and none.
146 · If you specify the none option, only checksums generated by
148 none are allowed.
149 · If you specify the innodb option, only checksums generated by
151 innodb are allowed.
152 · If you specify the crc32 option, only checksums generated by
154 crc32 are allowed.
155 · --no-check, -n
157 Ignore the checksum verification when rewriting a checksum. This
159 option may only be used with the innochecksum --write option. If
160 the --write option is not specified, innochecksum will terminate.
161 In this example, an innodb checksum is rewritten to replace an
163 invalid checksum:
164 shell> innochecksum --no-check --write innodb ../data/test/tab1.ibd
166 · --allow-mismatches, -a
168 The maximum number of checksum mismatches allowed before
170 innochecksum terminates. The default setting is 0. If
171 --allow-mismatches=N, where N>=0, N mismatches are permitted and
172 innochecksum terminates at N+1. When --allow-mismatches is set to
173 0, innochecksum terminates on the first checksum mismatch.
174 In this example, an existing innodb checksum is rewritten to set
176 --allow-mismatches to 1.
177 shell> innochecksum --allow-mismatches=1 --write innodb ../data/test/tab1.ibd
179 With --allow-mismatches set to 1, if there is a mismatch at page
181 600 and another at page 700 on a file with 1000 pages, the checksum
182 is updated for pages 0-599 and 601-699. Because --allow-mismatches
183 is set to 1, the checksum tolerates the first mismatch and
184 terminates on the second mismatch, leaving page 600 and pages
185 700-999 unchanged.
186 · --write=name, -w num
188 Rewrite a checksum. When rewriting an invalid checksum, the
190 --no-check option must be used together with the --write option.
191 The --no-check option tells innochecksum to ignore verification of
192 the invalid checksum. You do not have to specify the --no-check
193 option if the current checksum is valid.
194 An algorithm must be specified when using the --write option.
196 Possible values for the --write option are:
197 · innodb: A checksum calculated in software, using the original
199 algorithm from InnoDB.
200 · crc32: A checksum calculated using the crc32 algorithm,
202 possibly done with a hardware assist.
203 · none: A constant number.
205 The --write option rewrites entire pages to disk. If the new
207 checksum is identical to the existing checksum, the new checksum is
208 not written to disk in order to minimize I/O.
209 innochecksum obtains an exclusive lock when the --write option is
211 used.
212 In this example, a crc32 checksum is written for tab1.ibd:
214 shell> innochecksum -w crc32 ../data/test/tab1.ibd
216 In this example, a crc32 checksum is rewritten to replace an
218 invalid crc32 checksum:
219 shell> innochecksum --no-check --write crc32 ../data/test/tab1.ibd
221 · --page-type-summary, -S
223 Display a count of each page type in a tablespace. Example usage:
225 shell> innochecksum --page-type-summary ../data/test/tab1.ibd
227 Sample output for --page-type-summary:
229 File::../data/test/tab1.ibd
231 ================PAGE TYPE SUMMARY==============
232 #PAGE_COUNT PAGE_TYPE
233 ===============================================
234 2 Index page
235 0 Undo log page
236 1 Inode page
237 0 Insert buffer free list page
238 2 Freshly allocated page
239 1 Insert buffer bitmap
240 0 System page
241 0 Transaction system page
242 1 File Space Header
243 0 Extent descriptor page
244 0 BLOB page
245 0 Compressed BLOB page
246 0 Other type of page
247 ===============================================
248 Additional information:
249 Undo page type: 0 insert, 0 update, 0 other
250 Undo page state: 0 active, 0 cached, 0 to_free, 0 to_purge, 0 prepared, 0 other
251 · --page-type-dump, -D
253 Dump the page type information for each page in a tablespace to
255 stderr or stdout. Example usage:
256 shell> innochecksum --page-type-dump=/tmp/a.txt ../data/test/tab1.ibd
258 · --log, -l
260 Log output for the innochecksum tool. A log file name must be
262 provided. Log output contains checksum values for each tablespace
263 page. For uncompressed tables, LSN values are also provided. The
264 --log replaces the --debug option, which was available in earlier
265 releases. Example usage:
266 shell> innochecksum --log=/tmp/log.txt ../data/test/tab1.ibd
268 or:
270 shell> innochecksum -l /tmp/log.txt ../data/test/tab1.ibd
272 · - option.
274 Specify the - option to read from standard input. If the - option
276 is missing when “read from standard in” is expected, innochecksum
277 will output innochecksum usage information indicating that the “-”
278 option was omitted. Example usages:
279 shell> cat t1.ibd | innochecksum -
281 In this example, innochecksum writes the crc32 checksum algorithm
283 to a.ibd without changing the original t1.ibd file.
284 shell> cat t1.ibd | innochecksum --write=crc32 - > a.ibd
286 Running innochecksum on Multiple User-defined Tablespace Files.PP The
287 following examples demonstrate how to run innochecksum on multiple
288 user-defined tablespace files (.ibd files).
289 Run innochecksum for all tablespace (.ibd) files in the “test”
291 database:
292 shell> innochecksum ./data/test/*.ibd
294 Run innochecksum for all tablespace files (.ibd files) that have a file
296 name starting with “t”:
297 shell> innochecksum ./data/test/t*.ibd
299 Run innochecksum for all tablespace files (.ibd files) in the data
301 directory:
302 shell> innochecksum ./data/*/*.ibd
304 Note
307 Running innochecksum on multiple user-defined tablespace files is
308 not supported on Windows operating systems, as Windows shells such
309 as cmd.exe do not support glob pattern expansion. On Windows
310 systems, innochecksum must be run separately for each user-defined
311 tablespace file. For example:
312 cmd> innochecksum.exe t1.ibd
314 cmd> innochecksum.exe t2.ibd
315 cmd> innochecksum.exe t3.ibd
316 Running innochecksum on Multiple System Tablespace Files.PP By default,
317 there is only one InnoDB system tablespace file (ibdata1) but multiple
318 files for the system tablespace can be defined using the
319 innodb_data_file_path option. In the following example, three files for
320 the system tablespace are defined using the innodb_data_file_path
321 option: ibdata1, ibdata2, and ibdata3.
322 shell> ./bin/mysqld --no-defaults --innodb-data-file-path="ibdata1:10M;ibdata2:10M;ibdata3:10M:autoextend"
324 The three files (ibdata1, ibdata2, and ibdata3) form one logical system
326 tablespace. To run innochecksum on multiple files that form one logical
327 system tablespace, innochecksum requires the - option to read
328 tablespace files in from standard input, which is equivalent to
329 concatenating multiple files to create one single file. For the example
330 provided above, the following innochecksum command would be used:
331 shell> cat ibdata* | innochecksum -
333 Refer to the innochecksum options information for more information
335 about the “-” option.
336 Note
338 Running innochecksum on multiple files in the same tablespace is
339 not supported on Windows operating systems, as Windows shells such
340 as cmd.exe do not support glob pattern expansion. On Windows
341 systems, innochecksum must be run separately for each system
342 tablespace file. For example:
343 cmd> innochecksum.exe ibdata1
345 cmd> innochecksum.exe ibdata2
346 cmd> innochecksum.exe ibdata3
347
349 Copyright © 1997, 2019, Oracle and/or its affiliates. All rights
350 reserved.
351 This documentation is free software; you can redistribute it and/or
353 modify it only under the terms of the GNU General Public License as
354 published by the Free Software Foundation; version 2 of the License.
355 This documentation is distributed in the hope that it will be useful,
357 but WITHOUT ANY WARRANTY; without even the implied warranty of
358 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
359 General Public License for more details.
360 You should have received a copy of the GNU General Public License along
362 with the program; if not, write to the Free Software Foundation, Inc.,
363 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see
364 http://www.gnu.org/licenses/.
365
368 For more information, please refer to the MySQL Reference Manual, which
369 may already be installed locally and which is also available online at
370 http://dev.mysql.com/doc/.
371
373 Oracle Corporation (http://dev.mysql.com/).
374MySQL 8.0 09/06/2019 INNOCHECKSUM(1)