Mike Smith wrote:
I’ve seen a few performance posts on using different hardware
technologies to gain improvements. Most of those comments are on raid,
interface and rotation speed. One area that doesn’t seem to have
been mentioned is to run your disks empty.
...
On the outside of the disk you get a lot more data per seek than on the
inside. Double whammy you get it faster.
Performance can vary more than 100% between the outer and inner tracks
of the disk. So running a slower disk twice as big may give you more
benefit than running a small capacity 15K disk full. The slower disks
are also generally more reliable and mostly much cheaper.
...
This is not very green as you need to buy more disks for the same amount
of data and its liable to upset your purchasing department who won’t
understand why you don’t want to fill your disks up.
So presumably the empty-disk effect could also be achieved by partitioning, say 25% of the drive for the database, and 75% empty partition. But in fact, you could use that "low performance 75%" for rarely-used or static data, such as the output from pg_dump, that is written during non-peak times.
Pretty cool.
Craig
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