how much does vmstat say is being used for cache?

if it's not most of the other 14, then read I/O doesn't sound like the culprit

On Fri, Dec 4, 2009 at 4:17 PM, B. Todd Burruss <bburruss@real.com> wrote:
> thx for the tip.  i've allocated -Xmx2G for cassandra out of 16G.
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> On Fri, 2009-12-04 at 14:22 -0600, Brandon Williams wrote:
>> On Fri, Dec 4, 2009 at 1:40 PM, B. Todd Burruss <bburruss@real.com>
>> wrote:
>>         i've actually allocatted plenty of RAM, but it isn't fully
>>         used.  the
>>         read performance dwindles well before reaching a RAM limit.
>>
>>
>> You don't want to over-allocate memory to Cassandra, you want to leave
>> as much free as you can so the OS can cache the reads for you.
>>
>>
>> -Brandon
>>
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