[mythtv-users] Sloooow database

Curtis Stanford curtis at stanfordcomputing.com
Wed Jun 11 17:31:55 UTC 2008

On 11-Jun-08, at 10:24 AM, Roger Heflin wrote:

> Recently on my 1GB system (I moved things from a 2.8GB to a 1GB  
> system) I
> improved the database response by setting this setting with sysctl:
> sysctl -w vm.vfs_cache_pressure = 500
> This is supposed to reduce the amount of memory used for file cache  
> and has
> appeared to improve my database response quite a lot.  I did not see  
> the issue
> at all on the 2.8GB system, but it was often a problem on the 1GB  
> system, using
> this setting has appeared to correct the slow response I was having,  
> I am using
> a settop device and it actually was timing out about 1/2 of the time  
> when
> stopping a recording at the end (it was not having an issue on the  
> 2.8GB system,
> and so far after changing the setting it has not timed out).
> Given that the IO patterns of transcode/viewing recordings/writing  
> recordings is
> such that the data won't likely be reused from the cache soon  
> enough, it makes
> sense to not push out application pages for the vfs cache.

Thanks Roger! I'll give that a try.


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