Sponsored Content
Operating Systems AIX Anyone has experience with mirroring vg for Oracle Database and Application Post 302783623 by DGPickett on Wednesday 20th of March 2013 05:33:52 PM
Old 03-20-2013
Mirrors have double write overhead, a minimal issue if there are two cables and controllers involved, but with lots of I/o going on, there it is. On the flip side, your query bandwidth is doubled, as you can read either side. Of course, it is the same controllers, cables, spindles, heads, so total bandwidth for reading is not doubled, just congestion is avoided if a disk might be read in two places with the heads zipping back and forth.

Mirrors can outperform other raids because there is no parity overhead on write, and no parity overhead on a failed read.

If a volume is down, there is no double writing, which helps as there are no longer 2 places to read. When rebuilding the volume, unlike raid it is just a simple copy, but that is when the I/O capabilities are most reduced. While it is a risk, some shops hold off rebuilding volumes until off hours or the weekend.

Mirroring and RAID can happen at different levels of the software and hardware hierarchy. When at a lower level, special hardware can reduce the load. When at a higher level, it is easier to control the cost of activities like rebuilding so there is not a noticable load on the system.

Either way, one critical aspect of these redundant systems is the monitoring, so one failure is ignored until 2 cannot be ignored. Another is competence in repair work! It is tragic to pull the live mirror thinking it is the dead mirror . . . .
This User Gave Thanks to DGPickett For This Post:
 

4 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

UNIX Database / Application Installation

Greetings, forgive me if this is listed in another thread somewhere, I am short on time. I am being interviewed for the position of UNIX Database and Job code installer for a consulting firm. I have never installed or worked on a native UNIX system. I have been running Linux (RH,SuSE,Slackware)... (3 Replies)
Discussion started by: OllieTech
3 Replies

2. Solaris

Can't create database after Oracle Database installation

I installed Oracle 10 software on Solaris 11 Express, everything was fine execpt I can't create database using dbca.rsp file. I populated file with following options. OPERATION_TYPE = "createDatabase" GDBNAME = "solaris_user.domain.com" SID = "solaris_user" TEMPLATENAME = "General... (0 Replies)
Discussion started by: solaris_user
0 Replies

3. AIX

Filesystem using Oracle and mirroring VG ?

Hello, I have a filesystem which has Oracle EBS 11.5.9 running and database 9i # df -g Filesystem GB blocks Free %Used Iused %Iused Mounted on /dev/fslv00 270.00 69.68 75% 746263 5% /oratec which is in oraclevg # lsvg oraclevg VOLUME GROUP: ... (5 Replies)
Discussion started by: filosophizer
5 Replies

4. UNIX and Linux Applications

Identify a specific environment Oracle variable to connect a remote Oracle database ?

Good evening I nned your help pls, In an unix server i want to connect to a remote oracle databse server by sqlplus. I tried to find out the user/passwd and service name by env variable and all Ive got is this: ORACLE_SID_REPCOL=SCL_REPCOL ORACLE_SID=xmeta ORACLE_SID_TOL=SCL_PROTOLCOL... (2 Replies)
Discussion started by: alexcol
2 Replies
Jifty::DBI::Handle::Oracle(3pm) 			User Contributed Perl Documentation			   Jifty::DBI::Handle::Oracle(3pm)

NAME
Jifty::DBI::Handle::Oracle - An oracle specific Handle object SYNOPSIS
DESCRIPTION
This module provides a subclass of Jifty::DBI::Handle that compensates for some of the idiosyncrasies of Oracle. METHODS
connect PARAMHASH: Driver, Database, Host, User, Password Takes a paramhash and connects to your DBI datasource. database_version Returns value of ORA_OCI constant, see "Constants" in DBD::Oracle. insert Takes a table name as the first argument and assumes that the rest of the arguments are an array of key-value pairs to be inserted. build_dsn PARAMHASH Takes a bunch of parameters: Required: Driver, Database or Host/SID, Optional: Port and RequireSSL Builds a dsn suitable for an Oracle DBI connection blob_params column_NAME column_type Returns a hash ref for the bind_param call to identify BLOB types used by the current database for a particular column type. The current Oracle implementation only supports ORA_CLOB types(112). apply_limits STATEMENTREF ROWS_PER_PAGE FIRST_ROW takes an SQL SELECT statement and massages it to return ROWS_PER_PAGE starting with FIRST_ROW; distinct_query STATEMENTREF takes an incomplete SQL SELECT statement and massages it to return a DISTINCT result set. AUTHOR
Jesse Vincent, jesse@fsck.com SEE ALSO
Jifty::DBI, Jifty::DBI::Handle, DBD::Oracle perl v5.14.2 2011-04-26 Jifty::DBI::Handle::Oracle(3pm)
All times are GMT -4. The time now is 06:30 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy