[CentOS] kswapd taking 100% cpu with no swap on system

Mon May 9 18:03:54 UTC 2011
Brunner, Brian T. <BBrunner at gai-tronics.com>

> -----Original Message-----
> From: centos-bounces at centos.org 
> [mailto:centos-bounces at centos.org] On Behalf Of Ali Ahsan
> Sent: Monday, May 09, 2011 1:52 PM
> To: centos at centos.org
> Subject: Re: [CentOS] kswapd taking 100% cpu with no swap on system
> 
> On 05/09/2011 10:46 PM, Brunner, Brian T. wrote:
> >
> > 50GB in 0.12 ms is 500TB in 1.2 second.
> > SATA III buses at 6GB/sec need a "parallelness" of (nearly) 
> > 100 channels to soak up that data.
> > How many drives must be written-to in parallel to sustain that write
> > rate is ... Beyond my math skills.
> 
> Its only about Cassandra, not about my system :). SO whats your 
> suggestion about SATA driver ?

My suggestion:
That (first) you check your facts.  
What substantiates a claim of a 50GB/.12ms write-rate?  What
environment?
The claim is (AIUI) utterly misleading.  That (IMHO) gross
over-statement of Cassandra's write capacity makes any study of your
current system a pursuit after feral aquatic fowl.

I believe you were after an explanation as to why your kswapd was
running 100%? Lets stick to that and not drag in Cassandra vs MySQL.


Insert spiffy .sig here:
Life is complex: it has both real and imaginary parts.

//me
 
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