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InnoDB innodb_log_file_size [message #1326]

Sat, 26 May 2007 14:47

Speeple
Messages: 91
Registered: August 2006

Member

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!

Martin Gallagher | Speeple: The latest news

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Re: InnoDB innodb_log_file_size [message #1327 is a reply to message #1326 ]

Sat, 26 May 2007 16:58

carpii
Messages: 48
Registered: November 2006

Member

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 Smile

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Re: InnoDB innodb_log_file_size [message #1328 is a reply to message #1327 ]

Sun, 27 May 2007 07:19

Speeple
Messages: 91
Registered: August 2006

Member

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.

Martin Gallagher | Speeple: The latest news

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Re: InnoDB innodb_log_file_size [message #1330 is a reply to message #1326 ]

Sun, 27 May 2007 22:16

sterin
Messages: 324
Registered: March 2007
Location: Sweden

Senior Member

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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