[Gluster-devel] Scaled down a bit.

Chris Johnson johnson at nmr.mgh.harvard.edu
Wed Nov 28 18:30:49 UTC 2007

On Wed, 28 Nov 2007, Kevan Benson wrote:

      Ok, better.  Does work on the client side though.  Doesn't seem
to be to great on the server side for some reason.

      I just tried my simple test with readahead on the cl;ient side.
No difference.  Here's what I used.

volume readahead
   type performance/read-ahead
   option page-size 128kb ### in bytes
   option page-count 2 ### memory cache size is page-count x page-size per file
   subvolumes client
Maybe the page size or count needs to be bigger?

> Krishna Srinivas wrote:
>> On Nov 28, 2007 11:11 PM, Chris Johnson <johnson at nmr.mgh.harvard.edu> 
>> wrote:
>>> On Wed, 28 Nov 2007, Kevan Benson wrote:
>>>> Chris Johnson wrote:
>>>>>      I also tried the io-cache on the client side.  MAN does that
>>>>> work.  I had a 256 MB cache defind.  A reread of my 24 MB file took 72
>>>>> MS.  I don't think it even bothered with the server much.  I need to
>>>>> try that on the server.  Might help if a bunch of computer nodes
>>>>> hammer on the same file at the same time.
>>>> Careful with io-cache and io-threads together, depending on where you 
>>>> define
>>>> it (I think), the cache is per-thread.  so if you have 8 threads and a 
>>>> 256 MB
>>>> cache defined, be prepared for 2 GB of cache use...
>> No, If you define one io-cache translator there is only one cache. All the
>> threads will refer to the same io-cache translator with which it is 
>> associated
> Ah.  Is this newer?  I thought I tried this a few months ago and saw a lot of 
> memory usage.  Maybe I just ASSumed. ;)
> -- 
> -Kevan Benson
> -A-1 Networks

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