Bug #63966 | effective max innodb log file size is 2G, not 4G? | ||
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Submitted: | 9 Jan 2012 9:13 | Modified: | 14 May 2013 13:46 |
Reporter: | Hartmut Holzgraefe | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: Documentation | Severity: | S3 (Non-critical) |
Version: | any | OS: | Any |
Assigned to: | Bugs System | CPU Architecture: | Any |
[9 Jan 2012 9:13]
Hartmut Holzgraefe
[9 Jan 2012 11:26]
Valeriy Kravchuk
Thank you for the documentation request.
[24 Oct 2012 10:29]
James Day
Hartmut, The documentation number is right but the text is misleading. The number 4294967295 is 3.999999999068677 gigabytes, so you can't have a pair of 2G log files in 5.5 and earlier. "The combined size of log files must be less than 4GB" is a misleading statement in the text part of the description because 4G is too high, it should say that it's a little under 4G and recommend using a pair of 2047M files to get close enough to the limit for the difference not to matter. In 5.6 the limit is just under 512G and that should be enough for a few years. The variable can be set to 2^63-1 but it's reduced to full page increments, so you can't quite get that close to 512G. The 5.6 test is: 1897 if (srv_n_log_files * srv_log_file_size * UNIV_PAGE_SIZE 1898 >= 512ULL * 1024ULL * 1024ULL * 1024ULL) { 1899 /* log_block_convert_lsn_to_no() limits the returned block 1900 number to 1G and given that OS_FILE_LOG_BLOCK_SIZE is 512 1901 bytes, then we have a limit of 512 GB. If that limit is to 1902 be raised, then log_block_convert_lsn_to_no() must be 1903 modified. */ 1904 ib_logf(IB_LOG_LEVEL_ERROR, 1905 "Combined size of log files must be < 512 GB"); Try a pair of 255G log files if you want to get close enough to 512G in 5.6 for the difference not to matter much. Or go into a closer number of megabytes if you really need the extra almost two gigabytes that are available that way. James Day, MySQL Senior Principal Support Engineer, Oracle
[14 May 2013 13:46]
Bugs System
Revised reference manual content related to the maximum limit of innodb_log_file_size. Revisions made to 5.0, 5.1, 5.5, 5.6, 5.7 reference manuals.