Oracle DBA Resource: July 2018

Wednesday, July 25, 2018

Configure X11 on Exadata Compute Node

By default, X11 is disabled on Compute node and requires X11 libraries to install before the launch of any Oracle or other GUI tools.
here are rpm files required and commands to configure

Step1. Get the following files.

libdmx-1.1.3-3.el6.x86_64.rpm 100% 14KB 14.1KB/s 00:00

libICE-1.0.6-1.el6.x86_64.rpm 100% 52KB 52.1KB/s 00:00

libSM-1.2.1-2.el6.x86_64.rpm 100% 36KB 36.1KB/s 00:00

libXmu-1.1.1-2.el6.x86_64.rpm 100% 65KB 65.5KB/s 00:00

libXt-1.1.4-6.1.el6.x86_64.rpm 100% 164KB 164.0KB/s 00:00

libXxf86vm-1.1.3-2.1.el6.x86_64.rpm 100% 16KB 15.6KB/s 00:00

xorg-x11-utils-7.5-14.el6.x86_64.rpm 100% 100KB 100.1KB/s 00:00

xorg-x11-xauth-1.0.9-1.el6.x86_64.rpm 100% 44KB 43.8KB/s 00:00

Step2. Run the yum install command
[root@mbflxdbpdbadm01 ~]# yum install ./xorg-x11-xauth-1.0.9-1.el6.x86_64.rpm ./libXmu-1.1.1-2.el6.x86_64.rpm ./libXt-1.1.4-6.1.el6.x86_64.rpm ./libICE-1.0.6-1.el6.x86_64.rpm ./libSM-1.2.1-2.el6.x86_64.rpm
Setting up Install Process
Examining ./xorg-x11-xauth-1.0.9-1.el6.x86_64.rpm: 1:xorg-x11-xauth-1.0.9-1.el6.x86_64
Marking ./xorg-x11-xauth-1.0.9-1.el6.x86_64.rpm to be installed
Examining ./libXmu-1.1.1-2.el6.x86_64.rpm: libXmu-1.1.1-2.el6.x86_64
Marking ./libXmu-1.1.1-2.el6.x86_64.rpm to be installed
Examining ./libXt-1.1.4-6.1.el6.x86_64.rpm: libXt-1.1.4-6.1.el6.x86_64
Marking ./libXt-1.1.4-6.1.el6.x86_64.rpm to be installed
Examining ./libICE-1.0.6-1.el6.x86_64.rpm: libICE-1.0.6-1.el6.x86_64
Marking ./libICE-1.0.6-1.el6.x86_64.rpm to be installed
Examining ./libSM-1.2.1-2.el6.x86_64.rpm: libSM-1.2.1-2.el6.x86_64
Marking ./libSM-1.2.1-2.el6.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package libICE.x86_64 0:1.0.6-1.el6 will be installed
---> Package libSM.x86_64 0:1.2.1-2.el6 will be installed
---> Package libXmu.x86_64 0:1.1.1-2.el6 will be installed
---> Package libXt.x86_64 0:1.1.4-6.1.el6 will be installed
---> Package xorg-x11-xauth.x86_64 1:1.0.9-1.el6 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

==============================================================================================================================================
Package Arch Version Repository Size
==============================================================================================================================================
Installing:
libICE x86_64 1.0.6-1.el6 /libICE-1.0.6-1.el6.x86_64 115 k
libSM x86_64 1.2.1-2.el6 /libSM-1.2.1-2.el6.x86_64 76 k
libXmu x86_64 1.1.1-2.el6 /libXmu-1.1.1-2.el6.x86_64 154 k
libXt x86_64 1.1.4-6.1.el6 /libXt-1.1.4-6.1.el6.x86_64 406 k
xorg-x11-xauth x86_64 1:1.0.9-1.el6 /xorg-x11-xauth-1.0.9-1.el6.x86_64 89 k

Transaction Summary
==============================================================================================================================================
Install 5 Package(s)

Total size: 841 k
Installed size: 841 k
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Warning: RPMDB altered outside of yum.
Installing : libICE-1.0.6-1.el6.x86_64 1/5
Installing : libSM-1.2.1-2.el6.x86_64 2/5
Installing : libXt-1.1.4-6.1.el6.x86_64 3/5
Installing : libXmu-1.1.1-2.el6.x86_64 4/5
Installing : 1:xorg-x11-xauth-1.0.9-1.el6.x86_64 5/5
Verifying : libXmu-1.1.1-2.el6.x86_64 1/5
Verifying : libSM-1.2.1-2.el6.x86_64 2/5
Verifying : 1:xorg-x11-xauth-1.0.9-1.el6.x86_64 3/5
Verifying : libICE-1.0.6-1.el6.x86_64 4/5
Verifying : libXt-1.1.4-6.1.el6.x86_64 5/5

Installed:
libICE.x86_64 0:1.0.6-1.el6 libSM.x86_64 0:1.2.1-2.el6 libXmu.x86_64 0:1.1.1-2.el6 libXt.x86_64 0:1.1.4-6.1.el6
xorg-x11-xauth.x86_64 1:1.0.9-1.el6

Complete!
[root@mbflxdbpdbadm01 ~]#

Step3: copy the .Xauthority file to desired user home folder

[root@mbflxdbpdbadm01 ~]# cp .Xauthority /home/oracle/
[root@mbflxdbpdbadm01 ~]# chmod 600 /home/oracle/.Xauthority
[root@mbflxdbpdbadm01 ~]# chown oracle:oinstall /home/oracle/.Xauthority

Tuesday, July 10, 2018

Exadata: Reallocate OCR and VOTE disks to different Diskgroup

===================================
ocrconfig
Device/File not configured
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@mbflxdbpdbadm01 bin]# ./ocrconfig -delete +DATAC1
Device/File not configured
Device/File not configured
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
[root@mbflxdbpdbadm01 bin]# ./crsctl query css votedisk
SQL*Plus: Release 12.1.0.2.0 Production on Fri Jul 6 01:27:00 2018
Copyright (c) 1982, 2014, Oracle. All rights reserved.
SQL> create pfile='/tmp/asminit.ora' from spfile;
File created.
SQL>
[grid@mbflxdbpdbadm01 ~]$ sqlplus / as sysasm
SQL*Plus: Release 12.1.0.2.0 Production on Fri Jul 6 01:27:00 2018
Copyright (c) 1982, 2014, Oracle. All rights reserved.
SQL> create pfile='/tmp/asminit.ora' from spfile;
File created.
SQL> create spfile='+RECOC1' from pfile='/tmp/asminit.ora';
File created.
SQL> exit
[grid@mbflxdbpdbadm01 ~]$ gpnptool get
<?xml version="1.0" encoding="UTF-8"?><gpnp:GPnP-Profile Version="1.0" xmlns="http://www.grid-pnp.org/2005/11/gpnp-profile" xmlns:gpnp="http://www.grid-pnp.org/2005/11/gpnp-profile" xmlns:orcl="http://www.oracle.com/gpnp/2005/11/gpnp-profile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.grid-pnp.org/2005/11/gpnp-profile gpnp-profile.xsd" ProfileSequence="5" ClusterUId="4ac943e6090e5f51ffde516369905bf9" ClusterName="mbprodclus" PALocation=""><gpnp:Network-Profile><gpnp:HostNetwork id="gen" HostName="*"><gpnp:Network id="net1" IP="172.28.167.0" Adapter="bondeth0" Use="public"/><gpnp:Network id="net2" IP="192.168.68.0" Adapter="ib0" Use="cluster_interconnect"/><gpnp:Network id="net3" IP="192.168.68.0" Adapter="ib1" Use="cluster_interconnect"/></gpnp:HostNetwork></gpnp:Network-Profile><orcl:CSS-Profile id="css" DiscoveryString="+asm" LeaseDuration="400"/><orcl:ASM-Profile id="asm" DiscoveryString="o/*/*" SPFile="+RECOC1/mbprodclus/ASMPARAMETERFILE/registry.253.980731721" Mode="legacy"/><ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/><ds:Reference URI=""><ds:Transforms><ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/><ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"> <InclusiveNamespaces xmlns="http://www.w3.org/2001/10/xml-exc-c14n#" PrefixList="gpnp orcl xsi"/></ds:Transform></ds:Transforms><ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><ds:DigestValue>I5jcSBp+klSVfahABW28jC/wjns=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>kA26UJIgyVuhw/aNFbxta6pNfqUJbjitgwf593zUZzLIoHtXZmyQ6OCHA8jfr6aS6WpglFF3b0/do8YqIwnmu/IuY41mdyujtoJGUc+UavDHKZGohr5P62073iMx7oir04OPr8/QJ70zCGKzRAY0bC9N925Fz6Tc/GmuUITw/9Q=</ds:SignatureValue></ds:Signature></gpnp:GPnP-Profile>
[root@mbflxdbpdbadm01 bin]# ./crsctl start crs
GROUP_NUMBER INSTANCE_NAME
NAME TYPE VALUE
x

[root@mbflxdbpdbadm01 bin]# export ORACLE_SID=+ASM1
[root@mbflxdbpdbadm01 bin]# export ORACLE_HOME=/u01/app/12.1.0.2/grid
[root@mbflxdbpdbadm01 bin]# export PATH=$PATH:/u01/app/12.1.0.2/grid/bin

[root@mbflxdbpdbadm01 bin]# ./ocrconfig -add +RECOC1
[root@mbflxdbpdbadm01 bin]# ./ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 4
Total space (kbytes) : 409568
Used space (kbytes) : 1900
Available space (kbytes) : 407668
ID : 1202396802
Device/File Name : +DATAC1
Device/File integrity check succeeded
Device/File Name : +RECOC1
Device/File integrity check succeeded

[root@mbflxdbpdbadm01 bin]# ./ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 4
Total space (kbytes) : 409568
Used space (kbytes) : 1900
Available space (kbytes) : 407668
ID : 1202396802
Device/File Name : +RECOC1
Device/File integrity check succeeded

## STATE File Universal Id File Name Disk group
-- ----- ----------------- --------- ---------
1. ONLINE 659a51b34a524f84bf883eb244f50ea2 (o/192.168.68.109;192.168.68.110/DATAC1_CD_02_mbflxdbpceladm01) [DATAC1]
2. ONLINE 1d4d1487d2624f07bf9c82d73c539dbc (o/192.168.68.111;192.168.68.112/DATAC1_CD_02_mbflxdbpceladm02) [DATAC1]
3. ONLINE d204dc678b064f9cbfbdd770a5d822cd (o/192.168.68.113;192.168.68.114/DATAC1_CD_02_mbflxdbpceladm03) [DATAC1]
4. ONLINE e65991258f004f49bfaef77bea5430d0 (o/192.168.68.115;192.168.68.116/DATAC1_CD_02_mbflxdbpceladm04) [DATAC1]
5. ONLINE c2c0a61055e34f81bf2c25460df33ed5 (o/192.168.68.117;192.168.68.118/DATAC1_CD_02_mbflxdbpceladm05) [DATAC1]
Located 5 voting disk(s).
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]# ./crsctl replace votedisk +RECOC1
Successful addition of voting disk 5ed72da19a754fd7bf9a45c3a02506a9.
Successful addition of voting disk 23a445e9deaa4f44bf75890d000a25ec.
Successful addition of voting disk e9c35fa192e94f8ebf03e9eb3310a56e.
Successful addition of voting disk fd54a9a45b244f02bf9f584e4e5bef95.
Successful addition of voting disk c507ce6a04454f85bf49affaef9feb6a.
Successful deletion of voting disk 659a51b34a524f84bf883eb244f50ea2.
Successful deletion of voting disk 1d4d1487d2624f07bf9c82d73c539dbc.
Successful deletion of voting disk d204dc678b064f9cbfbdd770a5d822cd.
Successful deletion of voting disk e65991258f004f49bfaef77bea5430d0.
Successful deletion of voting disk c2c0a61055e34f81bf2c25460df33ed5.
Successfully replaced voting disk group with +RECOC1.
CRS-4266: Voting file(s) successfully replaced
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]# ./crsctl query css votedisk
## STATE File Universal Id File Name Disk group
-- ----- ----------------- --------- ---------
1. ONLINE 5ed72da19a754fd7bf9a45c3a02506a9 (o/192.168.68.109;192.168.68.110/RECOC1_CD_02_mbflxdbpceladm01) [RECOC1]
2. ONLINE 23a445e9deaa4f44bf75890d000a25ec (o/192.168.68.111;192.168.68.112/RECOC1_CD_02_mbflxdbpceladm02) [RECOC1]
3. ONLINE e9c35fa192e94f8ebf03e9eb3310a56e (o/192.168.68.113;192.168.68.114/RECOC1_CD_02_mbflxdbpceladm03) [RECOC1]
4. ONLINE fd54a9a45b244f02bf9f584e4e5bef95 (o/192.168.68.115;192.168.68.116/RECOC1_CD_02_mbflxdbpceladm04) [RECOC1]
5. ONLINE c507ce6a04454f85bf49affaef9feb6a (o/192.168.68.117;192.168.68.118/RECOC1_CD_02_mbflxdbpceladm05) [RECOC1]
Located 5 voting disk(s).
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]#

[grid@mbflxdbpdbadm01 ~]$ sqlplus / as sysasm

Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Real Application Clusters and Automatic Storage Management options

Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Real Application Clusters and Automatic Storage Management options

Disconnected from Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Real Application Clusters and Automatic Storage Management options

[grid@mbflxdbpdbadm01 ~]$

Warning: some command line parameters were defaulted. Resulting command line:
/u01/app/12.1.0.2/grid/bin/gpnptool.bin get -o-

Success.
[grid@mbflxdbpdbadm01 ~]$
[grid@mbflxdbpdbadm01 ~]$
[grid@mbflxdbpdbadm01 ~]$

CRS-2791: Starting shutdown of Oracle High Availability Services-managed resources on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.crsd' on 'mbflxdbpdbadm01'
CRS-2790: Starting shutdown of Cluster Ready Services-managed resources on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.DATAC1.dg' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.LISTENER.lsnr' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.LISTENER_SCAN2.lsnr' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.MGMTLSNR' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.DATAC1.dg' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.DBFS_DG.dg' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.RECOC1.dg' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.RECOC1.dg' on 'mbflxdbpdbadm01' succeeded
CRS-2677: Stop of 'ora.LISTENER.lsnr' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.mbflxdbpdbadm01.vip' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.LISTENER_SCAN2.lsnr' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.scan2.vip' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.MGMTLSNR' on 'mbflxdbpdbadm01' succeeded
CRS-2672: Attempting to start 'ora.MGMTLSNR' on 'mbflxdbpdbadm04'
CRS-2677: Stop of 'ora.DBFS_DG.dg' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.asm' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.asm' on 'mbflxdbpdbadm01' succeeded
CRS-2677: Stop of 'ora.scan2.vip' on 'mbflxdbpdbadm01' succeeded
CRS-2672: Attempting to start 'ora.scan2.vip' on 'mbflxdbpdbadm04'
CRS-2677: Stop of 'ora.mbflxdbpdbadm01.vip' on 'mbflxdbpdbadm01' succeeded
CRS-2672: Attempting to start 'ora.mbflxdbpdbadm01.vip' on 'mbflxdbpdbadm02'
CRS-2676: Start of 'ora.MGMTLSNR' on 'mbflxdbpdbadm04' succeeded
CRS-2676: Start of 'ora.scan2.vip' on 'mbflxdbpdbadm04' succeeded
CRS-2672: Attempting to start 'ora.LISTENER_SCAN2.lsnr' on 'mbflxdbpdbadm04'
CRS-2676: Start of 'ora.mbflxdbpdbadm01.vip' on 'mbflxdbpdbadm02' succeeded
CRS-2676: Start of 'ora.LISTENER_SCAN2.lsnr' on 'mbflxdbpdbadm04' succeeded
CRS-2673: Attempting to stop 'ora.ons' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.ons' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.net1.network' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.net1.network' on 'mbflxdbpdbadm01' succeeded
CRS-2792: Shutdown of Cluster Ready Services-managed resources on 'mbflxdbpdbadm01' has completed
CRS-2677: Stop of 'ora.crsd' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.storage' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.drivers.acfs' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.mdnsd' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.gpnpd' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.storage' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.asm' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.drivers.acfs' on 'mbflxdbpdbadm01' succeeded
CRS-2677: Stop of 'ora.mdnsd' on 'mbflxdbpdbadm01' succeeded
CRS-2677: Stop of 'ora.gpnpd' on 'mbflxdbpdbadm01' succeeded
CRS-2677: Stop of 'ora.asm' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.ctssd' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.evmd' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.cluster_interconnect.haip' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.ctssd' on 'mbflxdbpdbadm01' succeeded
CRS-2677: Stop of 'ora.evmd' on 'mbflxdbpdbadm01' succeeded
CRS-2677: Stop of 'ora.cluster_interconnect.haip' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.cssd' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.cssd' on 'mbflxdbpdbadm01' succeeded
CRS-2673: Attempting to stop 'ora.diskmon' on 'mbflxdbpdbadm01'
CRS-2673: Attempting to stop 'ora.gipcd' on 'mbflxdbpdbadm01'
CRS-2677: Stop of 'ora.gipcd' on 'mbflxdbpdbadm01' succeeded
CRS-2677: Stop of 'ora.diskmon' on 'mbflxdbpdbadm01' succeeded
CRS-2793: Shutdown of Oracle High Availability Services-managed resources on 'mbflxdbpdbadm01' has completed
CRS-4133: Oracle High Availability Services has been stopped.
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]#
[root@mbflxdbpdbadm01 bin]#

CRS-4123: Oracle High Availability Services has been started.

2 ;

------------ ----------------------------------------------------------------
DB_NAME CLUSTER_NAME STATUS
-------- ------------------------------- ------------
SOFTWARE_VERSION
------------------------------------------------------------
COMPATIBLE_VERSION CON_ID
------------------------------------------------------------ ----------
3 +ASM1
+ASM mbprodclus CONNECTED
12.1.0.2.0
12.1.0.2.0 0

------------------------------------ ----------- ------------------------------
spfile string +RECOC1/mbprodclus/ASMPARAMETE
RFILE/registry.253.980731721

SQL>
x

Disconnected
grid@mbflxdbpdbadm01 ~]$ export ORACLE_SID=+ASM1
Connected to:
Connected to:
[root@mbflxdbpdbadm01 bin]# ./crsctl stop crs
SQL> SELECT * from v$asm_client
SQL> show parameter spfile
x

Thursday, July 5, 2018

Exadata Redundancy

1) “External” redundancy diskgroups do not provide ASM mirroring.
2) “External” redundancy diskgroups rely on the redundancy provided outside Oracle (e.g. RAID 1, etc) at Storage level.
3) Therefore, on “External” redundancy diskgroups, if one disk member fails or is affected, then the diskgroup is dismounted or cannot be mounted back again, this behavior is expected, because an external redundancy diskgroup cannot tolerate the failure of any disk in the diskgroup.
4) Any kind of disk failure causes ASM to dismount the diskgroup or unable to mount it back.
5) For this reason, if the redundancy provided outside Oracle(ASM) is not offering the complete/correct coverage against corruptions or physical disk failures (expected redundancy), it is recommendable to implement/use "Normal" or "High" redundancy diskgroups instead, because ASM ("Normal" or "High" redundancy) provides redundancy with the use of failure groups, which are defined during diskgroup creation. The diskgroup type determines how ASM mirrors files. When you create a diskgroup, you indicate whether the diskgroup is a "Normal" redundancy diskgroup (2-way mirroring for most files by default) or a "High" redundancy diskgroup (3-way mirroring) or an "External" redundancy diskgroup (no mirroring by Oracle ASM).
6) Failgroups definition is specific to each storage setup, but you should follow these guidelines on "Normal" redundancy diskgroups:

a) All the failgroups (each failgroup), in the same diskgroup, must have the same number of disks to maintain the diskgroup redundancy (mirroring).

b) All the disks, in the same diskgroup, must have the same uniform size to guarantee the required redundancy as well.

c) All the disks, in the same diskgroup, must have the same I/O physical characteristics to provide a uniform I/O throughput among all the disks in the same diskgroup.

Note: Those rules must be followed when normal or high redundancy diskgroups are created and configured, otherwise it is a bad diskgroup design and ASM redundancy will not be guaranteed, thus ASM mirroring will be in risk and I/O performance will be compromised as well

Mirroring protects data by storing copies of data across different disks, providing access to user data in the event of a disk failure. When you create an ASM disk group, you specify a level of redundancy—this redundancy level dictates how many copies of data are maintained:

Normal redundancy = two-way mirror
High redundancy = three-way mirror
External redundancy = no ASM mirroring; ASM uses mirroring functionality in the storage array/subsystem, if available, to provide protection
With Exadata, Oracle protects and mirrors storage exclusively with ASM normal or high redundancy; there is no external redundancy alternative on Exadata.

The redundancy level controls how many disk failures are tolerated without ASM un-mounting the disk group or losing data.

When ASM allocates an extent for a mirrored file, it allocates a primary copy and one or two mirror copies. Oracle places the mirror copy on a disk that’s part of a different failure group. Failure groups are where mirror copies are stored. If you lost disks in either the primary location or failure group(s) (but not both or all), Oracle would continue to operate normally on the surviving copy.

ASM doesn’t mirror physical disks or LUNs like traditional RAID—it mirrors database extents. This is a very important design aspect of ASM—with normal or high redundancy, extents are mirrored on sectors from disks on one or more failure groups. These failure groups consist of disks different from the primary extents.

On Oracle Exadata, Oracle always places mirrored extents on grid disks located in a different storage server. This provides the flexibility that if you lost an entire storage server, you would still have access to either the primary or mirrored extents.

Wednesday, July 4, 2018

EXADATA: How to resize ASM disks

EXADATA: How to resize ASM disks

Requirement:
Reduce the space allocated to RECO Diskgroup and allocate the space to DATA diskgroup.
Exclusion:
No change in redundacy at any level.
No add or drop any griddisk.
Approach:
1.Check the free space in celldisk and griddisk of both DATA and RECO
2.resize the RECO diskgroup
3.resize (reduction) griddisk of RECO diskgroup
4.resize (addition) griddisk of DATA diskgroup
5.resize the DATA diskgroup.
6.Check the free space
7.conclude
Steps:
1.Login to storage cell and check

# cellcli -e "list celldisk where name like 'CD.*' attributes name, size, freespace"

# cellcli -e "list griddisk where name like 'DATA.*' attributes name, size"
# cellcli -e "list griddisk where name like 'RECO.*' attributes name, size"

2. Login to ASM instance in compute node

$ sqlplus / as sysasm
SQL> alter diskgroup RECO resize all size 20000M rebalance power 32;
SQL> select name, total_mb from v$asm_disk_stat where name like 'RECO%';

3. Login to *ALL* Storage cell and resize for RECO
# cellcli -e alter griddisk RECO_CD_00_exacell01, RECO_CD_01_exacell01, RECO_CD_02_exacell01, RECO_CD_03_exacell01, RECO_CD_04_exacell01, RECO_CD_05_exacell01, RECO_CD_06_exacell01, RECO_CD_07_exacell01, RECO_CD_08_exacell01, RECO_CD_09_exacell01, RECO_CD_10_exacell01, RECO_CD_11_exacell01 size=234176M;

4. Login to *ALL* Storage cell and resize for DATA
# cellcli -e alter griddisk DATA_CD_00_exacell01, DATA_CD_01_exacell01, DATA_CD_02_exacell01, DATA_CD_03_exacell01, DATA_CD_04_exacell01, DATA_CD_05_exacell01, DATA_CD_06_exacell01, DATA_CD_07_exacell01, DATA_CD_08_exacell01, DATA_CD_09_exacell01, DATA_CD_10_exacell01, DATA_CD_11_exacell01 size=300G;

5. Login to ASM instance in compute node and resize grid disk for DATA

$ sqlplus / as sysasm
SQL> alter diskgroup DATA resize all rebalance power 32;

6. check free space
SQL> select name, total_mb/1024 "GB" from v$asm_disk_stat where name like 'DATA%';

Oracle DBA Resource