01-21-2011
Oracle Database 10g runs I/O operations from both shared memory and process-private regions using the new HP-UX asynchronous driver. However, I/O operations through the asynchronous driver are not asynchronous in nature. This is because Oracle Database must perform a blocking wait to check the status of I/O operations submitted to the asynchronous driver. This causes some Oracle processes, such as the database writer process, to essentially process synchronous I/O.
This is an extract from
this link
seems like asynchronous I/O on HP-UX with Oracle is only supported for raw FS
How many DB writer are currently set up on your DB ?
Few considerations about it you might want to prefer:
a) the FS type hosting the datafile can handle async I/O (oracle param DISK_ASYNCH_IO = true) so the DB writer can let the OS deal with the update (without having to do "wait" events)
b) if your FS type doesn't support async I/O you can setup more than 1 DBWR (DBWR_PROCESSES/db_writer_processes) but since the oracle buffer cache is divided in as much working sets, you might want to adjust the DB_BLOCK_LRU_LATCHES.
c) Last solution, activate the forking to simulate asynch I/O by activating the use of slave processes (DBWn_IO_SLAVES) which are in fact synchronous I/O (DISK_ASYNCH_IO = false). Risks of that last solution are buffer overhead, wait, memory overhead (IPCs & context switch)
Last edited by ctsgnb; 01-21-2011 at 05:16 PM..
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LEARN ABOUT ULTRIX
nsquery
nsquery(1) General Commands Manual nsquery(1)
Name
nsquery - name server query command
Syntax
/usr/ucb/nsquery [ lookup ] [ host ] [ server ]
Description
The command provides an interface to obtain host name and address information.
If you specify host, the command obtains information about the specified host. If no host is specified, the command obtains information
about the local host system.
If you specify server, the command queries the BIND server that you specify. If you do not specify a server, the command queries the
default BIND server.
Options
lookup Retrieves the host name, Internet Protocol (IP) address, and aliases of the specified host. If no host or server is specified, the
command obtains information about the local system from the default BIND server.
If you do specify the lookup option, the command obtains the information about the BIND server and host specified (or their
defaults). If the system from which you issue the command is a BIND server, and you do not specify the lookup option, information
about only that server is retrieved.
Files
Directory containing BIND server data file
BIND server boot file
Host database file containing name to address mapping for BIND primary
server
Host database file containing address to name mapping for BIND primary
server
Local host database file containing address to name mapping for BIND
server
BIND server cache file
BIND data file
See Also
nslookup(1), resolver(3), resolver(5), named(8)
Guide to the BIND/Hesiod Service
nsquery(1)