Why Voting Disk & OCR not on ASM?

What could be the reason not to have Voting disk and OCR on ASM.
Is it that, we require Voting Disk and OCR before ASM? Any idea?

user9198889 wrote:
but this doesnt seem to be a problem with 11.2 anymore! oracle 11g r2 recomends storing ocr and voting disks on asm? why is does?
how does it work ?
i cant get my head around thisOn 11gR2 we can keep OCR and VOTE in ASM Diskgroup.
see start process
http://download.oracle.com/docs/cd/E11882_01/rac.112/e10717/intro.htm#CEGDBFIE
10g -> 11gR1, we create ASM diskgroup from database software
11gR2, we create ASM diskgroup from cluster software.
recomends storing ocr and voting disks on asm? why is does? 11gR2 not support raw devices, support ASM and CFS

Similar Messages

Recovery scenario - Voting disk does not match with the cluster guid

Hi all,
Think of you can not start your guest VMs just because it has a corrupted system.img root image. And assume it contains 5 physical disk( which are all created by the RAC template) hence ASM on them.
What is the simplest recovery scneario of the guest vms (RAC)?
Can it be a feasible scenario for recover of the availablity? (Assume both of the RAC system images are corrupted and we prefer not a system level recovery rather than backup / restore)
1. Create 2 RAC instances using the same networking and hostname details as the ones that are corrupted. - Use 5 different new disks.
2 Shutdown the newly created instances. Drop the disks from the newly created instances using VM manager.
3. Add the old disks whose system image is failing to be recoverd but ASM disks are still in use (from the newly created instances using VM manager.) to the newly created instances.
4. Open the newly created instances
Can we expect the ASM and CRS could be initialized and be opened without a problem?
When I try this scenario I get the folllowing error from the cssd/crsd .
- Cluster guid 9112ddc0824fefd5ff2b7f9f7be8f048 found in voting disk does not match with the cluster guid a3eec66a2854ff0bffe784260856f92a obtained from the GPnP profile.
- Found 0 configured voting files but 1 voting files are required, terminating to ensure data integrity.
What could be the simplest way of recovery of a virtual machine that has healthy ASM disks but corrupted system image?
Thank you

Hi,
you have a similar problem, when trying to clone databases with 11.2.
The problem is that a cluster is uniquely identified, and this information is hold in the OCR and the Voting disks. So exactly these 2 are not to be cloned.
To achieve what you want, simply setup your system in that way, that you have a separate diskgroup for OCR and Voting (and ASM spfile), which is not to be restored in this case of szeanrio.
Only all database files in ASM will then be exchanged later.
Then what you want can be achieved.
However I am not sure that the RAC templates have the option to install OCR and Voting into a separated diskgroup.
Regards
Sebastian

AddNode.sh fails when Voting Disks are placed in ASM

Hi Forum, adding a node with addNode script throws an error when Voting disks are placed on ASM. Did anyone else had this issue or any ideas ?
Thanks a lot for your help.
[grid@host02 bin]$ sh -x ./addNode.sh -silent "CLUSTER_NEW_NODES={host01}" "CLUSTER_NEW_VIRTUAL_HOSTNAMES={host01-vip}"
+ OHOME=/u01/app/11.2.0/grid
+ INVPTRLOC=/u01/app/11.2.0/grid/oraInst.loc
+ ADDNODE='/u01/app/11.2.0/grid/oui/bin/runInstaller -addNode -invPtrLoc /u01/app/11.2.0/grid/oraInst.loc ORACLE_HOME=/u01/app/11.2.0/grid -silent CLUSTER_NEW_NODES={host01} CLUSTER_NEW_VIRTUAL_HOSTNAMES={host01-vip}'
+ '[' '' = Y -o '!' -f /u01/app/11.2.0/grid/cv/cvutl/check_nodeadd.pl ']'
+ CHECK_NODEADD='/u01/app/11.2.0/grid/perl/bin/perl /u01/app/11.2.0/grid/cv/cvutl/check_nodeadd.pl -pre -silent CLUSTER_NEW_NODES={host01} CLUSTER_NEW_VIRTUAL_HOSTNAMES={host01-vip}'
+ /u01/app/11.2.0/grid/perl/bin/perl /u01/app/11.2.0/grid/cv/cvutl/check_nodeadd.pl -pre -silent 'CLUSTER_NEW_NODES={host01}' 'CLUSTER_NEW_VIRTUAL_HOSTNAMES={host01-vip}'
+ '[' 1 -eq 0 ']'
[grid@host02 bin]$
Output from /u01/app/11.2.0/grid/cv/log/cvutrace.log.0:
<snipped>
TaskVotingDisk:Voting Disk:TASK_SUMMARY:FAILED:CRITICAL:VERIFICATION_FAILED
ERRORMSG(GLOBAL): PRVF-5430 : Voting disk configuration does not meet Oracle's recommendation of three voting disk locations
ERRORMSG(GLOBAL): PRVF-5431 : Oracle Cluster Voting Disk configuration check failed
ERRORMSG(host01): PRVF-5449 : Check of Voting Disk location "ORCL:SPT_OCRVOTE01(ORCL:SPT_OCRVOTE01)" failed on the following nodes:
ERRORMSG(host01): No such file or directory
ERRORMSG(host01): PRVF-5449 : Check of Voting Disk location "ORCL:SPT_OCRVOTE02(ORCL:SPT_OCRVOTE02)" failed on the following nodes:
ERRORMSG(host01): No such file or directory
<snipped>
Edited by: user12857528 on 14/11/2010 18:39

Thanks Sebastian, brilliant - setting of IGNORE_PREADDNODE_CHECKS=Y did the trick !
The only thing is that my neat 3 Voting disks are reduced to two only now:
Before it was:
[grid@host02 bin]# ./crsctl query css votedisk
## STATE File Universal Id File Name Disk group
1. ONLINE 4dea88bcf2fa4f11bfdbcca6e3aade14 (ORCL:SPT_OCRVOTE01) [SPT_OCRVOTE]
2. ONLINE 71e395e6e30e4febbf907305dc7827c6 (ORCL:SPT_OCRVOTE02) [SPT_OCRVOTE]
3. ONLINE 187d3474f0fe4fe0bf5cec1bb35203ae (ORCL:SPT_OCRVOTE03) [SPT_OCRVOTE]
Located 3 voting disk(s).
where now it is:
[grid@host01 bin]$ ./crsctl query css votedisk
## STATE File Universal Id File Name Disk group
1. ONLINE 4dea88bcf2fa4f11bfdbcca6e3aade14 (ORCL:SPT_OCRVOTE01) [SPT_OCRVOTE]
2. ONLINE 71e395e6e30e4febbf907305dc7827c6 (ORCL:SPT_OCRVOTE02) [SPT_OCRVOTE]
Located 2 voting disk(s).
and third disk is in mount_status closed after adding node host01.

Why is disk optimization not available on our Surface with 8.1?

We have a Surface with Windows 8.1 RT. When I go to the Tools and try to Optimize (trim) the SSD it says "Optimization not available" and the Analyze and Optimize buttons are greyed out. I've seen posts where others are able to optimize
their drives, so what am I missing in this case. I checked the Services for Optimization and it was set to manual, but even when turning it on at startup automatically it makes no difference. Any ideas on how to optimize on the Surface?
Why is the option available if you can't use it?

This is normal for SSD.
Do some reading here:
Should You Defrag an SSD?
How to Use "Optimize Drives" to Defrag HDD and TRIM SSD in Windows 8 and 8.1
S.Sengupta, Windows Entertainment and Connected Home MVP
S. Sengupta, I think you are missing the point of my original post. Of course I know you don't defrag an SSD. But you can optimize them using Trim. I have two other notebooks running Windows 8.1 and both have the ability to optimize the
SSDs as shown in the screenshot AnaBna posted. This is not normal behavior for the options to be greyed out, and only our Surface with 8.1 RT exhibits this behavior. Possibly this IS normal for a Surface, and if there is anyone else out there with
a Surface (regular, not Pro) willing to look they can tell me if theirs is also un-optimizable. The only thing that makes me think other's with a Surface can optimize is that when I searched for a solution to this others mention they can do this on their
Surface.
I say this with all respect, but I think sometimes on this forum people just fire off answers very quickly without really reading the whole question or knowing the answer just to get credit for posts and points.

OCR and voting disk location

Hi all,
I'm testing to install an Oracle RAC database (11g) on linux RHE 5 with a shared storage DELL Equallogic SCSI SAN.
I will setup a 2 nodes and i will use ASM for the database storage. I'm new in RAC database and i'm checking some docs and find that for the installation should have 3 volumes.
1- volumes for OCR and voting disk
2- volume for Database file (ASM)
3- volume for flash Recovery area and archive log file (ASM)
My question is which file system i will use for OCR and voting disk volume as i know for Datafiles and flash recovery area i will use ASM, but for voting disk i cannot use ASM because the system will access first OCR before starting ASm instance.
If i will use other file system how can i do ?
Thank you.

Hi
Thank you all for your help, actually i'm again facing problem in installing ASMlib, i cannot find ASMlib package for my OS even Raw device service is also not present.
My OS is CentOS 6 and Oracle 11g R2 RAC then installation type.
[root@Etopup-srv01 ~]# cat /etc/redhat-release
CentOS release 6.4 (Final)
Would you please help me what can i do to configure my ASM disk group ?
Thank you.

OCR and Voting Disk partition

Dear all
I uninstall clusterware. And i want to install again that but when i made partition in windows 2003 then CVU fail the stage command.
I did the following things..
1) diskpart --->select Disk 1----> clean -->exit (both the nodes)
2) diskpart -->automount enable--->exit ---> restart (both the nodes)
3) Then i make four partition in one node. And see after restart node 2 have that partition with drive letter. I remove all the drive letter.
But CVU stage command failed. And if i run clusterware then it can get partition which has not previous OCR and voting. I think previous OCR and Voting disk could not clean.
Could u pls tell me how can i get solution.
Moinul

Check Metalink for this problem area ! Raise TAR

How to rename voting disk name in oracle clusterware 11gr2

Hi:
I need change the name of voting disk at os level, original name is /dev/rhdisk20, I need rename to /dev/asmocr_vote1 (unix AIX), the voting disk is locate in ASM diskgroup +OCR.
Initial voting disk was: /dev/rhdisk20 in diskgroup +OCR
#(root) /oracle/GRID/11203/bin->./crsctl query css votedisk
## STATE File Universal Id File Name Disk group
1. ONLINE a2e6bb7e57044fcabf0d97f40357da18 (/dev/rhdisk20) [OCR]
I createt a new alias disk name:
#mknod /dev/asmocr_vote01 c 18 10
# /dev->ls -lrt|grep "18, 10"
brw------- 1 root system 18, 10 Aug 27 13:15 hdisk20
crw-rw---- 1 oracle asmadmin 18, 10 Sep 6 16:57 rhdisk20 --> Old name
crw-rw---- 1 oracle asmadmin 18, 10 Sep 6 16:59 asmocr_vote01 ---> alias to old name, the new name.
After change votingn disk unix name, the cluster doesn't start, voting disk is not found by CRSSD.
-STEPS to start clusterware after changing the OS voting disk name are:
1- stop al nodes:
#crsctl stop crs -f (every node)
Work only in one node (node1, +ASM1 instance):
2- Change asm_diskstring in init+ASM1.ora:
asm_diskstring = /dev/asm*
3- change disk unix permiss:
# /dev->ls -lrt|grep "18, 10"
brw------- 1 root system 18, 10 Aug 27 13:15 hdisk20
crw-rw---- 1 root system 18, 10 Sep 6 16:59 asmocr_vote01
crw-rw---- 1 oracle asmadmin 18, 10 Sep 6 17:37 rhdisk20
#(root) /dev->chown oracle:asmadmin asmocr_vote01
#(root) /dev->chown root:system rhdisk20
#(root) /dev->ls -lrt|grep "18, 10"
brw------- 1 root system 18, 10 Aug 27 13:15 hdisk20
crw-rw---- 1 oracle asmadmin 18, 10 Sep 6 16:59 asmocr_vote01 --> new name only have oracle:oinstall
crw-rw---- 1 root system 18, 10 Sep 6 17:37 rhdisk20
4-start node in exclusive mode:
# (root) /oracle/GRID/11203/bin->./crsctl start crs -excl
CRS-4123: Oracle High Availability Services has been started.
CRS-2672: Attempting to start 'ora.mdnsd' on 'orarac3intg'
CRS-2676: Start of 'ora.mdnsd' on 'orarac3intg' succeeded
CRS-2672: Attempting to start 'ora.gpnpd' on 'orarac3intg'
CRS-2676: Start of 'ora.gpnpd' on 'orarac3intg' succeeded
CRS-2672: Attempting to start 'ora.cssdmonitor' on 'orarac3intg'
CRS-2672: Attempting to start 'ora.gipcd' on 'orarac3intg'
CRS-2676: Start of 'ora.cssdmonitor' on 'orarac3intg' succeeded
CRS-2676: Start of 'ora.gipcd' on 'orarac3intg' succeeded
CRS-2672: Attempting to start 'ora.cssd' on 'orarac3intg'
CRS-2672: Attempting to start 'ora.diskmon' on 'orarac3intg'
CRS-2676: Start of 'ora.diskmon' on 'orarac3intg' succeeded
CRS-2676: Start of 'ora.cssd' on 'orarac3intg' succeeded
CRS-2672: Attempting to start 'ora.ctssd' on 'orarac3intg'
CRS-2672: Attempting to start 'ora.drivers.acfs' on 'orarac3intg'
CRS-2679: Attempting to clean 'ora.cluster_interconnect.haip' on 'orarac3intg'
CRS-2681: Clean of 'ora.cluster_interconnect.haip' on 'orarac3intg' succeeded
CRS-2672: Attempting to start 'ora.cluster_interconnect.haip' on 'orarac3intg'
CRS-2676: Start of 'ora.ctssd' on 'orarac3intg' succeeded
CRS-2676: Start of 'ora.drivers.acfs' on 'orarac3intg' succeeded
CRS-2676: Start of 'ora.cluster_interconnect.haip' on 'orarac3intg' succeeded
CRS-2672: Attempting to start 'ora.asm' on 'orarac3intg'
CRS-2676: Start of 'ora.asm' on 'orarac3intg' succeeded
CRS-2672: Attempting to start 'ora.crsd' on 'orarac3intg'
CRS-2676: Start of 'ora.crsd' on 'orarac3intg' succeeded
5-check votedisk:
# (root) /oracle/GRID/11203/bin->./crsctl query css votedisk
Located 0 voting disk(s).
--> NO VOTING DISK found
6- mount diskgroup of voting disk (+OCR in this case) in +ASM1 instance:
SQL> ALTER DISKGROUP OCR mount;
7-add votedisk belongs diskgroup +OCR:
# (root) /oracle/GRID/11203/bin->./crsctl replace votedisk +OCR
Successful addition of voting disk 86d8b12b1c294f5ebfa66f7f482f41ec.
Successfully replaced voting disk group with +OCR.
CRS-4266: Voting file(s) successfully replaced
#(root) /oracle/GRID/11203/bin->./crsctl query css votedisk
## STATE File Universal Id File Name Disk group
1. ONLINE 86d8b12b1c294f5ebfa66f7f482f41ec (/dev/asmocr_vote01) [OCR]
Located 1 voting disk(s).
8-stop node:
#(root) /oracle/GRID/11203/bin->./crsctl stop crs –f
8-start node:
#(root) /oracle/GRID/11203/bin->./crsctl start crs
10- check:
# (root) /oracle/GRID/11203/bin->./crsctl query css votedisk
## STATE File Universal Id File Name Disk group
1. ONLINE 86d8b12b1c294f5ebfa66f7f482f41ec (/dev/asmocr_vote01) [OCR]
Vicente.
HP.
Edited by: 957649 on 07-sep-2012 13:11

There is no facilty to rename a column name in Oracle 8i. This is possible from Oracle 9.2 version onwards.
For you task one example given below.
Example:-
Already existed table is ITEMS
columns in ITEMS are ITID, ITEMNAME.
But instead of ITID I want ITEMID.
Solution:-
step 1 :- create table items_dup
as select itid itemid, itemname from items;
step 2 :- drop table items;
step 3 :- rename items_dup to items;
Result:-
ITEMS table contains columns ITEMID, ITEMNAME

Backing up Voting disk in 11.2

Grid Version : 11.2
In 10.2, 11.1 , Voting disk can be backed up using
dd if=voting_disk_name of=backup_file_name bs=4kBut in 11.2, the voting disk is in ASM Disk Group. Is there a way to make sure that Voting disk is separately backed up?

spiral wrote:
Grid Version : 11.2
In 10.2, 11.1 , Voting disk can be backed up using
dd if=voting_disk_name of=backup_file_name bs=4kBut in 11.2, the voting disk is in ASM Disk Group. Is there a way to make sure that Voting disk is separately backed up?Hi,
Backing up and restoring voting disks using DD is only supported in versions prior to Oracle Clusterware 11.2.
With Oracle Clusterware 11.2 voting disks contain more information. Hence, one must not operate on voting disks using DD. This holds true regardless of whether or not the voting disks are stored in ASM, on a cluster file system, or on raw / block devices (which could still be the case after an upgrade).
Since DD must not be used to backup the voting disks with 11.2 anymore, the voting disks are backed up automatically into OCR. Since the OCR is backed up every 4 hours automatically, the voting disks are backed up indirectly, too. Any change to the information stored in the voting disks - e.g. due to the addition or removal of nodes in the cluster - triggers a new voting disk backup in the OCR.
Regards,
Levi Pereira

Minimum number of voting disks?

Hi,
Is there is a minimum number of voting disks?
does that depend on the RAC nodes?
If I have 4 nodes what is the optimal voting disks?
Thanks

user9202785 wrote:
Hi,
Is there is a minimum number of voting disks?
does that depend on the RAC nodes?
If I have 4 nodes what is the optimal voting disks?
ThanksOracle recommends 3 voting disk. but you can install clusterware with one voting disk by selecting external redudancy during clusterware installation.
the number of voting disks is not depend on the number of RAC nodes. you can have upto maximum 32 voting disks for 2nodes to 100 RAC nodes.
The Oracle Clusterware is comprised primarily of two components: the voting disk and the OCR (Oracle Cluster Registry). The voting disk is nothing but a file that contains and manages information of all the node memberships and the OCR is a file that manages the cluster and RAC configuration.
refer : how to add/remove/repace voting disk in the below link:
http://oracleinstance.blogspot.com/2009/12/how-to-addremovereplacemove-oracle.html.
if voting disk fails: refer
http://oracleinstance.blogspot.com/2009/12/how-to-addremovereplacemove-oracle.html.
also refer Oracle® Database 2 Day + Real Application Clusters Guide 10g Release 2 (10.2)
read the below ,hope this will help you.
1) Why do we have to create odd number of voting disk?
As far as voting disks are concerned, a node must be able to access strictly more than half of the voting disks at any time. So if you want to be able to tolerate a failure of n voting disks, you must have at least 2n+1 configured. (n=1 means 3 voting disks). You can configure up to 32 voting disks, providing protection against 15 simultaneous disk failures.
Oracle recommends that customers use 3 or more voting disks in Oracle RAC 10g Release 2. Note: For best availability, the 3 voting files should be physically separate disks. It is recommended to use an odd number as 4 disks will not be any more highly available than 3 disks, 1/2 of 3 is 1.5...rounded to 2, 1/2 of 4 is 2, once we lose 2 disks, our cluster will fail with both 4 voting disks or 3 voting disks.
2) Does the cluster actually check for the vote count before node eviction? If yes, could you expain this process briefly?
Yes. If you lose half or more of all of your voting disks, then nodes get evicted from the cluster, or nodes kick themselves out of the cluster.
3) What's the logic behind the documentaion note that says that "each node should be able to see more than half of the voting disks at any time"?
The answer to first question itself will provide answer to this question too.answered by: Boochi
refer: Question on voting disk
Question on voting disk

At the time of recovering voting disk

os:redhat linux
rdbms:10.2.0.1
clusterware:10.2.01.
hai...
we are using three voting disks for our cluster.i have taken backup of these three voting disks indivdually.like voting_disk1_bkp,voting_disk2_bkp,voting_disk3_bkp
suddenly the drive of voting_disk_file2 file has failed.
now i have to recover the voting_disk_file2.which method do i need to follow?
1)dd if=voting_disk2_bkp of=voting_disk_name
or
2)crsctl add css votedisk <path>
and why should we take individual backup of votking disks?
is these three voting disks are not equal?
please guide me.
v.s.srinivas

Also be aware that in 10g theres a bug; Some of the the docs and books say that you can do "crsctl add css votedisk " with the "-force" option to add a voting disk with the cluster up. This can cause corruption - see Note:390880.1
Yours,
Bob

Why logical partition is a must for voting disk and OCR

Hi Guys,
I just started handling jobs for RAC installation, I have a simple question regarding the setup.
Why does logical partition have to be used for voting disk and OCR?
I tried partition the disk that were provisioned for voting disk and OCR with primary partition but when OUI is trying to recognize the disk, it cannot find the disk that has been partitioned with primary partition.
Thank you,
Adhika

Hello Adhika,
I found it on this doc http://download.oracle.com/docs/cd/B28359_01/install.111/b28250/storage.htm
Be aware of the following restrictions for partitions:
* You cannot use primary partitions for storing Oracle Clusterware files while running the OUI to install Oracle Clusterware as described in Chapter 5, "Installing Oracle Clusterware". You must create logical drives inside extended partitions for the disks to be used by Oracle Clusterware files and Oracle ASM.
* With 32-bit Windows, you cannot create more than four primary disk partitions for each disk. One of the primary partitions can be an extend partition, which can then be subdivided into multiple logical partitions.
* You can assign mount points only to primary partitions and logical drives.
* You must create logical drives inside extended partitions for the disks to be used by Oracle Clusterware files and Oracle ASM.
* Oracle recommends that you limit the number of partitions you create on a single disk to prevent disk contention. Therefore, you may prefer to use extended partitions rather than primary partitions.
For these reasons, you might prefer to use extended partitions for storing Oracle software files and not primary partitions.
All the best,
Rodrigo Mufalani
http://www.mrdba.com.br/mufalani

OCFS2 , ASM and Raw Device for Voting Disk and OCR

Dear all ,
My manager assigned me to establish a 11gRAC , 3 node on OEL. He likes to locate ASM with datafiles , at the same time, 2 OCR vol on OCFS2 and RawDevice respectively , 2 voting disks on OCFS2 and RawDevice respectively also.
This really annoys me .
Oh all experts, could anybody give me some advices ? Can those stuff be co-existed ?

Billy Verreynne wrote:
MccLok wrote:
My manager assigned me to establish a 11gRAC , 3 node on OEL. He likes to locate ASM with datafiles , at the same time, 2 OCR vol on OCFS2 and RawDevice respectively , 2 voting disks on OCFS2 and RawDevice respectively also. Not a great idea to introduce additional s/w layers between the CRS software and its OCR and voting disks. If ocfs2 is for example used as a shared file system for these devices (files), then the ocfs2 cluster s/w needs to be up and running, the shared devices mounted, before CRS can successfully start. Thus any problem with the ocfs2 stack, will impact on CRS. Why? What does ocfs2 buy you in this regard? What are the benefits that justifies the increased complexity and the dependency of CRS on another s/w layer?
Fewer moving parts means less complexity, less stuff that needs to be configured and can go wrong.In fact, some users had perception that " Pay mroe so that Get more".

OCR and voting disks on ASM, problems in case of fail-over instances

Hi everybody
in case at your site you :
- have an 11.2 fail-over cluster using Grid Infrastructure (CRS, OCR, voting disks),
where you have yourself created additional CRS resources to handle single-node db instances,
their listener, their disks and so on (which are started only on one node at a time,
can fail from that node and restart to another);
- have put OCR and voting disks into an ASM diskgroup (as strongly suggested by Oracle);
then you might have problems (as we had) because you might:
- reach max number of diskgroups handled by an ASM instance (63 only, above which you get ORA-15068);
- experiment delays (especially in case of multipath), find fake CRS resources, etc.
whenever you dismount disks from one node and mount to another;
So (if both conditions are true) you might be interested in this story,
then please keep reading on for the boring details.
One step backward (I'll try to keep it simple).
Oracle Grid Infrastructure is mainly used by RAC db instances,
which means that any db you create usually has one instance started on each node,
and all instances access read / write the same disks from each node.
So, ASM instance on each node will mount diskgroups in Shared Mode,
because the same diskgroups are mounted also by other ASM instances on the other nodes.
ASM instances have a spfile parameter CLUSTER_DATABASE=true (and this parameter implies
that every diskgroup is mounted in Shared Mode, among other things).
In this context, it is quite obvious that Oracle strongly recommends to put OCR and voting disks
inside ASM: this (usually called CRS_DATA) will become diskgroup number 1
and ASM instances will mount it before CRS starts.
Then, additional diskgroup will be added by users, for DATA, REDO, FRA etc of each RAC db,
and will be mounted later when a RAC db instance starts on the specific node.
In case of fail-over cluster, where instances are not RAC type and there is
only one instance running (on one of the nodes) at any time for each db, it is different.
All diskgroups of db instances don't need to be mounted in Shared Mode,
because they are used by one instance only at a time
(on the contrary, they should be mounted in Exclusive Mode).
Yet, if you follow Oracle advice and put OCR and voting inside ASM, then:
- at installation OUI will start ASM instance on each node with CLUSTER_DATABASE=true;
- the first diskgroup, which contains OCR and votings, will be mounted Shared Mode;
- all other diskgroups, used by each db instance, will be mounted Shared Mode, too,
even if you'll take care that they'll be mounted by one ASM instance at a time.
At our site, for our three-nodes cluster, this fact has two consequences.
One conseguence is that we hit ORA-15068 limit (max 63 diskgroups) earlier than expected:
- none ot the instances on this cluster are Production (only Test, Dev, etc);
- we planned to have usually 10 instances on each node, each of them with 3 diskgroups (DATA, REDO, FRA),
so 30 diskgroups each node, for a total of 90 diskgroups (30 instances) on the cluster;
- in case one node failed, surviving two should get resources of the failing node,
in the worst case: one node with 60 diskgroups (20 instances), the other one with 30 diskgroups (10 instances)
- in case two nodes failed, the only node survived should not be able to mount additional diskgroups
(because of limit of max 63 diskgroup mounted by an ASM instance), so all other would remain unmounted
and their db instances stopped (they are not Production instances);
But it didn't worked, since ASM has parameter CLUSTER_DATABASE=true, so you cannot mount 90 diskgroups,
you can mount 62 globally (once a diskgroup is mounted on one node, it is given a number between 2 and 63,
and other diskgroups mounted on other nodes cannot reuse that number).
So as a matter of fact we can mount only 21 diskgroups (about 7 instances) on each node.
The second conseguence is that, every time our CRS handmade scripts dismount diskgroups
from one node and mount it to another, there are delays in the range of seconds (especially with multipath).
Also we found inside CRS log that, whenever we mounted diskgroups (on one node only), then
behind the scenes were created on the fly additional fake resources
of type ora*.dg, maybe to accomodate the fact that on other nodes those diskgroups were left unmounted
(once again, instances are single-node here, and not RAC type).
That's all.
Did anyone go into similar problems?
We opened a SR to Oracle asking about what options do we have here, and we are disappointed by their answer.
Regards
Oscar

Hi Klaas-Jan
- best practises require that also online redolog files are in a separate diskgroup, in case of ASM logical corruption (we are a little bit paranoid): in case DATA dg gets corrupted, you can restore Full backup plus Archived RedoLog plus Online Redolog (otherwise you will stop at the latest Archived).
So we have 3 diskgroups for each db instance: DATA, REDO, FRA.
- in case of fail-over cluster (active-passive), Oracle provide some templates of CRS scripts (in $CRS_HOME/crs/crs/public) that you edit and change at your will, also you might create additionale scripts in case of additional resources you might need (Oracle Agents, backups agent, file systems, monitoring tools, etc)
About our problem, the only solution is to move OCR and voting disks from ASM and change pfile af all ASM instance (parameter CLUSTER_DATABASE from true to false ).
Oracle aswers were a litlle bit odd:
- first they told us to use Grid Standalone (without CRS, OCR, voting at all), but we told them that we needed a Fail-over solution
- then they told us to use RAC Single Node, which actually has some better features, in csae of planned fail-over it might be able to migreate
client sessions without causing a reconnect (for SELECTs only, not in case of a running transaction), but we already have a few fail-over cluster, we cannot change them all
So we plan to move OCR and voting disks into block devices (we think that the other solution, which needs a Shared File System, will take longer).
Thanks Marko for pointing us to OCFS2 pros / cons.
We asked Oracle a confirmation that it supported, they said yes but it is discouraged (and also, doesn't work with OUI nor ASMCA).
Anyway that's the simplest approach, this is a non-Prod cluster, we'll start here and if everthing is fine, after a while we'll do it also on Prod ones.
- Note 605828.1, paragraph 5, Configuring non-raw multipath devices for Oracle Clusterware 11g (11.1.0, 11.2.0) on RHEL5/OL5
- Note 428681.1: OCR / Vote disk Maintenance Operations: (ADD/REMOVE/REPLACE/MOVE)
-"Grid Infrastructure Install on Linux", paragraph 3.1.6, Table 3-2
Oscar

Advantage of having OCR and Voting disk on ASM

What are advantages of putting OCR and Voting disk on ASM from 11g

well, other than the sharing thing, you dont have to go RAIDing an additional shared disk either. If you have properly configured ASM, redundancy should be built in as well, either soft or hard.
not sure what other advantages you may need. Theres the IO thing with ASM, buit thats not really an advantage persay with ocr and vote. I may be contradicted by others but Ive never seen performance hit of any kind attributed to ocr and vote on non-ASM disk.

Backup and Restore OCR,Voting Disk and ASM Disks in new SAN-10g RAC

Dear Friends,
I am using 10g R2 RAC serup on Linux
My OCR,Voting Disk and ASM Disk for DBF Files are on a SAN box
Now i am reorganising SAN by scrapping the entire SAN and cretaing new LUN's (It's a must)
so pleae let me know
1) how do i take backup of OCR and Voting Disk from existing SAN and how do i restore it in new LUN's after SAN reorganisation
2) how do i take backup of existing Database's from existing SAN and how do i restore it in new LUN's after SAN reorganisation.
I will be doing it in Planned downtime only
Regards,
DB

For step 1 you should following metalink doc.
For step 2 here is simple backup command script.
I have done this in windows for you.
D:\app\ranjit\product\11.2.0\dbhome_1\BIN>rman target /
Recovery Manager: Release 11.2.0.1.0 - Production on Wed Feb 8 21:48:47 2012
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
connected to target database: ORCL (DBID=1299593730)
RMAN> run
+{+
allocate channel c1 device type disk format 'D:\app\ranjit\rman\%U';
allocate channel c2 device type disk format 'D:\app\ranjit\rman\%U';
backup database;
backup current controlfile format 'D:\app\ranjit\rman\%U';
+}+
Regards

Why Voting Disk & OCR not on ASM?

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