Luke Lonergan wrote:
> Cool!
>
> At what rate does your disk setup write sequential data, e.g.:
> time dd if=/dev/zero of=bigfile bs=8k count=500000
>
> (sized for 2x RAM on a system with 2GB)
>
> BTW - the Compaq smartarray controllers are pretty broken on Linux from a
> performance standpoint in our experience. We've had disastrously bad
> results from the SmartArray 5i and 6 controllers on kernels from 2.4 ->
> 2.6.10, on the order of 20MB/s.
O.k. this strikes me as interesting, now we know that Compaq and Dell
are borked for Linux. Is there a name brand server (read Enterprise)
that actually does provide reasonable performance?
>
> For comparison, the results on our dual opteron with a single LSI SCSI
> controller with software RAID0 on a 2.6.10 kernel:
>
> [llonergan@stinger4 dbfast]$ time dd if=/dev/zero of=bigfile bs=8k
> count=500000
> 500000+0 records in
> 500000+0 records out
>
> real 0m24.702s
> user 0m0.077s
> sys 0m8.794s
>
> Which calculates out to about 161MB/s.
>
> - Luke
>
>
> On 7/21/05 2:55 PM, "Mark Wong" <markw@osdl.org> wrote:
>
>
>>I just ran through a few tests with the v14 patch against 100GB of data
>>from dbt3 and found a 30% improvement; 3.6 hours vs 5.3 hours. Just to
>>give a few details, I only loaded data and started a COPY in parallel
>>for each the data files:
>>http://www.testing.osdl.org/projects/dbt3testing/results/fast_copy/
>>
>>Here's a visual of my disk layout, for those familiar with the database
>>schema:
>>http://www.testing.osdl.org/projects/dbt3testing/results/fast_copy/layout-dev4
>>-010-dbt3.html
>>
>>I have 6 arrays of fourteen 15k rpm drives in a split-bus configuration
>>attached to a 4-way itanium2 via 6 compaq smartarray pci-x controllers.
>>
>>Let me know if you have any questions.
>>
>>Mark
>>
>
>
>
>
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