Re: switch from file system to raw device

Igor wrote:

>
> We have made some testing and found from 50 to 70% better performance
> on raw logical volume. But that has been on different storage system, so
> might really have changed. Means I will have to adapt backup procedure...
> At last, this particular db will not live more than a year, year and a
> half ... so might really not be worth worrying about...
>

Raw vs Cooked file system performance has been discussed many, many times. With the changes in hardware in the past few years, with improvements in file systems, with increased memory & double buffering (ouch), with RAID and with 'SAME', I have seen a number of papers indicating that going to RAW just is not worth the effort. The gains are frequently minimal, if any.

On my small Linux machines, the 3% benefit certainly did not make it worth my while.

Of course, _your_ environment might not match the environment used in the papers, and you might see a significant performance benefit.

If your environment is that susceptible to the disk performance, you might also get some benefit from the old (myth-age) style of separating tablespaces to separate disk drives & controllers, etc. However, other than for keeping someone busy, I would not recommend resurrecting those techniques! Received on Wed Sep 15 2004 - 10:36:40 CDT