Luke Lonergan wrote:

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:

[EMAIL PROTECTED] dbfast]$ time dd if=/dev/zero of=bigfile bs=8k
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" <[EMAIL PROTECTED]> 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:

Here's a visual of my disk layout, for those familiar with the database

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.


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