fragment size and file system block size

[PAUL CHEN_2]

I would like to know when I create a database with db_block_size 8K, should I create the file system block size and frament size with 8k to get better performance?

[Alexander M. Ermes]

Hi there.
We did it that way, and the performance is really satifying.
Rgds
Alexander M. Ermes

[PAUL CHEN_2]

Alexander,
You meant you created 8K for file system block and fragment sizes and you got better performance. Did you compare it with file system block size is 8k, but fragment size is 1k.

Thanks,

Paul

[Yogeeraj_1]

hi,
An OS blocksize of 8k would be pretty huge.

But, you just want your blocksize to be a MULTIPLE of that of the OS.

If we ask for 32k for a single block IO -- and in ONE call to the os kernel, we'll get it.

Much more efficient than asking for 4-8k reads one after the other.

Oracle use this concept even more with db_file_multiblock_read_count where we can do one OS request to read more then one Oracle block which in turn may be many many more OS blocks.

hope this helps!

regards
Yogeeraj