# InnoDB innodb\_log\_file\_size

**URL:** <https://forums.percona.com/t/innodb-innodb-log-file-size/335>\
**Category:** Other MySQL® Questions\
**Created:** [May 26, 2007, 1:17pm UTC](https://forums.percona.com/t/innodb-innodb-log-file-size/335 "2007-05-26T13:17:52Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Speeple](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@Speeple](https://forums.percona.com/u/Speeple)\
**Post date:** [May 26, 2007, 1:17pm UTC](https://forums.percona.com/t/innodb-innodb-log-file-size/335/1 "2007-05-26T13:17:52Z")

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Hi,

I have a server with 16Gb RAM, 8Gb of which is used by innodb\_buffer\_pool\_size.

Now, innodb\_log\_file\_size is almost 25% (combined limit of innodb is 4Gb), so it’s around 1.9xGb is size.

Is this OTT (feels like it to me!)? Peter notes generally using 128Mb to 512Mb for this variable, I don’t know what size of RAM his comments are in relation to.

Also, are portions of innodb\_log\_file\_size stored in RAM?

Cheers!

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**Author:** ![carpii](https://avatars.discourse-cdn.com/v4/letter/c/b5ac83/32.png) [@carpii](https://forums.percona.com/u/carpii)\
**Post date:** [May 26, 2007, 3:28pm UTC](https://forums.percona.com/t/innodb-innodb-log-file-size/335/2 "2007-05-26T15:28:12Z")

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I cant answer your question, but take a look at the example configs that come with mysql. Theres configs for small, large and huge.  
If the huge config (referring to database size and hardware) is using a large value, then its safe to assume its not OTT )

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<div class="post-metadata">

**Author:** ![Speeple](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@Speeple](https://forums.percona.com/u/Speeple)\
**Post date:** [May 27, 2007, 5:49am UTC](https://forums.percona.com/t/innodb-innodb-log-file-size/335/3 "2007-05-27T05:49:10Z")

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Thanks buddy, the huge-innodb config only has 4Gb of RAM, so it’s hard to know how things relate on a system with 4x the RAM. E.g. is it simply linear? For now I’ve set each log file at 1Gb, with a combined of 2Gb. My gut feeling is that this is high enough.

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**Author:** ![sterin](https://avatars.discourse-cdn.com/v4/letter/s/3ab097/32.png) [@sterin](https://forums.percona.com/u/sterin)\
**Post date:** [May 27, 2007, 8:46pm UTC](https://forums.percona.com/t/innodb-innodb-log-file-size/335/4 "2007-05-27T20:46:33Z")

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The InnoDB log file is not stored in RAM more than the innodb\_log\_buffer\_size variable defines.  
Usually between 1 and 8 MB.  
This does usually not need to scale linearly.

The log files is generally recommended to be about 25% of the innodb\_buffer\_pool\_size. While there is a total of 4GB for all log files for a 32bit system.

But I would also say that you can be content with 2x1G.

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<div class="post-metadata">

**Author:** ![Speeple](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@Speeple](https://forums.percona.com/u/Speeple)\
**Post date:** [May 28, 2007, 6:10am UTC](https://forums.percona.com/t/innodb-innodb-log-file-size/335/5 "2007-05-28T06:10:25Z")

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Cheers!

The 4Gb combined limit occurs on my 64Bit setup too.

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**Author:** ![tanj](https://avatars.discourse-cdn.com/v4/letter/t/e5b9ba/32.png) [@tanj](https://forums.percona.com/u/tanj)\
**Post date:** [May 29, 2007, 9:36am UTC](https://forums.percona.com/t/innodb-innodb-log-file-size/335/6 "2007-05-29T09:36:55Z")

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[http://www.mysqlperformanceblog.com/2007/05/09/how-to-estima](http://www.mysqlperformanceblog.com/2007/05/09/how-to-estima) te-time-it-takes-innodb-to-recover/

The 25% hint is IMHO related to older setups (not everybody can afford 16G RAM in a server )) So virtually having files \> to 1GB would cause recovery and shutdown times to be extremely slow and inefficient.