ORA-01105: mount is incompatible with mounts by other instances ORA-19808: recovery destination parameter mismatch

ORA-01105: mount is incompatible with mounts by other instances
ORA-19808: recovery destination parameter mismatch


Cause: it occurs in RAC environment. issue is due to mismatch of DB_RECOVERY parameters between nodes.
Solution: Make sure the parameters db_recovery_file_dest,db_recovery_file_dest_size are same for all nodes

Example:

Node-1
SQL> show parameter recovery
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string +DATA
db_recovery_file_dest_size big integer 10G
recovery_parallelism integer 0

Node-2
SQL> show parameter recovery
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string +DATA
db_recovery_file_dest_size big integer 100G
recovery_parallelism integer 0

SQL> startup
ORACLE instance started.
Total System Global Area 4275781632 bytes
Fixed Size 2235208 bytes
Variable Size 1694500024 bytes
Database Buffers 2566914048 bytes
Redo Buffers 12132352 bytes
ORA-01105: mount is incompatible with mounts by other instances
ORA-19808: recovery destination parameter mismatch

to clear this error and mount the database set  db_recovery_file_dest_size same on both nodes.
SQL> alter system set db_recovery_file_dest_size = 100G scope=spfile;
 System altered.

SQL> startup
ORACLE instance started.
Total System Global Area 4275781632 bytes
Fixed Size 2235208 bytes
Variable Size 1694500024 bytes
Database Buffers 2566914048 bytes
Redo Buffers 12132352 bytes
Database mounted.
Database opened. 

CRS-4700: The Cluster Time Synchronization Service is in Observer mode.

CRS-4700: The Cluster Time Synchronization Service is in Observer mode.

or 

How to switch from NTP to CTSS?

It is recommended to use CTSS for a cluster to synchronize the time between cluster nodes instead of NTP.

We will find the CTSS status in observer mode when ntp.conf file is in /etc/.

1. Check if ctssd is active or not

cd /u01/app/11.2.0.4/grid/bin

[oracle@test_node01 ~]$ ./crsctl check ctss

CRS-4700: The Cluster Time Synchronization Service is in Observer mode.

[oracle@test_node02 ~]$ ./crsctl check ctss

CRS-4700: The Cluster Time Synchronization Service is in Observer mode.

We can see that CTSSD is in observer mode

2. Stop  NTP and CRS

now we are going to disable the ntp service and enable CTSS service

#crsctl stop crs

#/sbin/service ntpd stop

#mv /etc/ntp.conf /etc/ntp.conf.original

3. Start the cluster on all nodes

#crsctl start crs

4. Check that ctssd automatically starts in active mode as shown below

[root@test_node02 etc]# crsctl check ctss

CRS-4701: The Cluster Time Synchronization Service is in Active mode.

CRS-4702: Offset (in msec): 0

[root@test_node01 etc]# crsctl check ctss

CRS-4701: The Cluster Time Synchronization Service is in Active mode.

CRS-4702: Offset (in msec): 0

./cluvfy comp clocksync

Verifying Clock Synchronization across the cluster nodes

Checking if Clusterware is installed on all nodes...

Check of Clusterware install passed

Checking if CTSS Resource is running on all nodes...

CTSS resource check passed

Querying CTSS for time offset on all nodes...

Query of CTSS for time offset passed

Check CTSS state started...

CTSS is in Active state. Proceeding with check of clock time offsets on all nodes...

Check of clock time offsets passed

Oracle Cluster Time Synchronization Services check passed

Verification of Clock Synchronization across the cluster nodes was successful.

[cssd(10157)]CRS-1714: Unable to discover any voting files, retrying discovery in 15 seconds

[cssd(10157)]CRS-1714: Unable to discover any voting files, retrying discovery in 15 seconds

Cause:

The above error occurred in my case after reboot of RAC nodes and then we tried to bring up the cluster . We found this in alert log of node.

Issue is during the start-up of cluster, the previously created partitions on disks are not recognized by nodes.

[root@test_node02 ]# /usr/sbin/oracleasm scandisks

Reloading disk partitions: done

Cleaning any stale ASM disks...

Scanning system for ASM disks...

[root@test_node02 ]# /usr/sbin/oracleasm listdisks

[root@test_node02 ]#

Solution:

Try to recognize the disks manually as below

/etc/init.d/oracleasm stop

/etc/init.d/oracleasm start

/usr/sbin/oracleasm scandisks /dev/sdd*

[root@test_node02 ]# /usr/sbin/oracleasm listdisks

ASM_FRA03

ASM_FRA04

ASM_DATA01

ASM_DATA02

OCR01

this is one of the solution to above error.there may be other reasons also that could cause this.for my case issue is resolved after scanning the disks manually.

Cheers...!!!!