Yesterday Yuva Kishore is commented on my Oracleasm - Instantiating disk : failed post and asked a question: We can list the asm disks (listdisks) but where can we find the mapping that ASMDISK1 is mapped to /dev/sda1 and so on?
I want answer this question with this post.
If you are using ASMLib for configure ASM Disks, then you can use following steps for define which device mapped which ASM Disk.
As you know, oracleasm listdisks is return only ASM disk names
[grid@oel62-rac1 ~]$ oracleasm listdisks
If you want find which ASM disk is mapped which device, then you must use oracleasm querydisk with ASM disk name.
[grid@oel62-rac1 ~]$ oracleasm querydisk -d ASMDISK01
Disk "ASMDISK01" Is a valid ASM disk On device[8,17]
As see you, ASMDISK01 is valid ASM disk on device [8,17].
What is means? It means ASMDISK01 is mapped to device [8,17].
How to find [8,17] device? We must use Linux ls –l c…
When you need safely remove broker-managed Data Guard Configuration then, oracle recommend following steps…
You know dg_broker_start parameter is TRUE and data guard configuration information contains in broker configuration files dg_broker_config_file1, dg_broker_config_file2 with broker-managed Data Guard Configuration.
Following steps I use on my test machines witch is running on Oracle Virtual Box. I captures video on this machines, too. Primary and Standby Database running on Oracle Linux Server 6.2 and installed Oracle Database 11g Release 2 (188.8.131.52).
DG – is my breoker-managed Data Guard configuration. admdb is primary database, stldb – is standby database.
DGMGRL> show configuration
Configuration - dg
Protection Mode: MaxPerformance
admdb - Primary database
stldb - Physical standby database
Fast-Start Failover: DISABLED
Archive log destinations like as
Prior to Oracle Database 12c Release 2 have a problem with long identifier name, for example, in 11.2 version you cannot create long name (max 30 Bytes) tables. As you see, from screenshots length of table name column is maximum 30.
In Oracle Database 12c Release 2 changed the length of identifier names, and this change depends on the COMPATIBLE initialization parameter. Documentation says:
If COMPATIBLE is set to a value of 12.2 or higher, then names must be from 1 to 128 bytes long with these exceptions: Names of databases are limited to 8 bytes. Names of disk groups, pluggable databases (PDBs), rollback segments, tablespaces, and tablespace sets are limited to 30 bytes. If an identifier includes multiple parts separated by periods, then each attribute can be up to 128 bytes long. Each period separator, as well as any surrounding double quotation marks, counts as one byte. For example, suppose you identify a column like this: "schema"."table"."column" …