What's VxFS buffer size ?

From: Bass Chorng <bchorng_at_yahoo.com>
Date: 31 Jul 2001 15:34:24 -0700
Message-ID: <bd9a9a76.0107311434.54483b3d@posting.google.com>

In Steve Adam's article of "Why a Large Database Block Size", he points out that all Unix file system buffer size are invariably 8K.

Does anybody know what VxFS default buffer size is ? Is it tuneable ? How large can it go ? How do you verify it ? And how do you change it ?

The other question is, if I can beef it up , do I still benefit from raw on my datafiles ? I am talking about a database that's not write intensive at all.

I tested our system (VxFS, no QIO) with full table scan in very large db_file_multiblock_read_count and examine the trace file. The blocks that Oracle is reading per IO is maxed at 256K. So I know for sure VxFS is not
operating at the same 8K buffer size like ufs.

Thanks for any knowledge sharing in advance.

-Bass Chorng Received on Tue Jul 31 2001 - 17:34:24 CDT