[mythtv-users] Where are those new 1TB drives?

jedi at mishnet.org jedi at mishnet.org
Mon Mar 12 16:28:41 UTC 2007


> On Monday 12 March 2007 15:14, jedi at mishnet.org wrote:
>>     That's a very dangerous assumption. It's rediculously easy to
>> overwhelm the RAM cache on even the most expensive SAN hardware.
> That's what I also thought untill I did some serious stress tests.
> I changed read/write ratios, random I/O, sequential I/O, number of
> threads, ...  The differences between raid 5 and raid 10 was max 5%.....

IOW, you did a "benchmark".

You created an artificial situation specifically designed to create
a working set that can fit into whatever cache happens to be under
discussion: cpu, hba, san.

That still doesn't have any real relevance to real world workloads.

This is why the people that run the companies that sell the sort of
highend gear you're speaking of still recommend SCSI over SATA for
it's better command queuing.

Plus an extra 5% can be very relevant for some applications.



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