RE: Hard Disk selections

Van: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] Namens Paul Drake
Verzonden: donderdag 22 september 2005 17:20 Aan: bunjibry_at_gmail.com
CC: Oracle-L
Onderwerp: Re: Hard Disk selections

Bryan,

It depends.
What you have going for you is:

CPU bogomips (500 MHz to likely 3.4 GHz) Memory bandwidth (100 MHz FSB to 800 MHz effective) Newer disks tend to have faster interfaces, larger cache, higher RPMs and shorter seek times.
The SAN will likely have some form of cache.

>This triggered me. We had some issues with a SAN cache not being configured
at all. Result was the throughput became >lousy although the disks were fast enough. What I learned from it is that you have to check if this is configured correctly >before looking at your database.

If you're only loading up data into the buffer cache at instance startup and only writing to disk for redo, controlfile and archived redo logs, you may not notice the fewer disks.

If you find that the CBO wants to do all table scans, you're in trouble.

The only way to know for sure is to test. Get as much memory in the box as your budget allows and only use half of it. Use w2k advanced server instead of w2k server, as it has the /PAE and /3GB options.
W2k3 server standard edition supports the /3GB option.

hth.

Paul

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