Re: Latency of "direct path reads"
- From: Austin Hackett <hacketta_57@xxxxxx>
- To: oracle-l digest users <oracle-l@xxxxxxxxxxxxx>
- Date: Mon, 19 Aug 2013 22:38:41 +0100
Hi Amir
I've recently deployed a 5 node 11.2.0.3.2 RAC with dNFS and a NetApp FAS6290
into production.
Are you familiar with MOS Doc ID 1495104.1, which has a list of Recommended
Patches for Direct NFS? If you don't have these patches applied, I would
definitely suggest getting them installed. For example, during my initial lab
tests I kept hitting bug 15987992 under heavy sequential read load. I/O would
completely hang for a seemingly indefinite period. Admittedly, this doesn't
sound like what you're seeing. However, there are other bugs mentioned which
sound like they could be of interest. You may need to request back ports of the
patches for your exact PSU-level. I did.
Apologies if this is old news.
Regarding your question about sending > 32K chunks of data, the Oracle
recommended value for the rsize mount option is 32K, so I think a 1MB multi
block read would be split into 32K chunks under KNFS anyway. I don't know if
DNFS uses a larger transfer buffer size?
Austin
--
//www.freelists.org/webpage/oracle-l
Other related posts:
