||Oracle Tips by Burleson
Disk I/O Tuning
ATA Tuning in LINUX
values include 0 to disable 32-bit I/O support (sets it to 16
bit), 1 to enable 32-bit data transfers, and 3 to enable 32-bit
data transfers with a special sync sequence required by many
chipsets. The value 3 works with nearly all 32-bit IDE
chipsets, but incurs slightly more overhead. Note that "32-bit"
refers to data transfers across a PCI or VLB bus to the
interface card only; all (E)IDE drives still have a 16-bit
connection over the ribbon cable from the interface card.
- Disable/enable the "using_dma" flag for this drive. This
option now works with most combinations of drives and PCI
interfaces, which support DMA and which are known to the IDE
driver. It is also a good idea to use the appropriate -X option
in combination with -d1 to ensure the drive itself is programmed
for the correct DMA mode, although most BIOSs should do this for
you at boot time. Using DMA nearly always gives the best
performance, with fast I/O throughput and low CPU usage. But
there are at least a few configurations of chipsets and drives
for which DMA does not make much of a difference, or may even
slow things down (on really messed up hardware!). Your mileage
- Sync and flush the buffer cache for the device on exit. This
operation is also performed as part of the -t and -T timings.
- Display the drive geometry (cylinders, heads, sectors), the
size (in sectors) of the device, and the starting offset (in
sectors) of the device from the beginning of the drive.
The above text is
an excerpt from:
Oracle Disk I/O Tuning
Disk IO Performance & Optimization for Oracle
by Mike Ault
can offer world-class remote Oracle database support at super-affordable prices.
Oracle DBA service provides 100% of the remote Oracle database administration
needs for your company, and includes 24x7 access to our staff of 100% OCP
Certified Oracle DBAs.
We require a 12 month service commitment and include the following services:
- Initial configuration review and problem identification
- Installation of Oracle statistics collection mechanisms and quarterly
database growth summaries
- Hourly monitoring of your Oracle database for pending problems
- Periodic performance analysis & identification of tuning activities
- Twenty Four hour Oracle emergency support
- Reporting and resolving all serious Oracle alert log messages
- Free use of the BC
- Quick response emergency support for production database outages
- Four hours of free remote DBA support every month. You can use these free
hours for any DBA activity, including database analysis, system design,
production migrations or personal mentoring.
information, please visit
www.oracle-training.cc or email email@example.com.