Interview Questions.

Top 100+ Oracle Rac/asm Interview Questions And Answers

fluid

Top 100+ Oracle Rac/asm Interview Questions And Answers

Question 1. What Is The Main Purpose Of Oracle Real Application Clusters (rac)?

Answer :

Oracle Real Application (RAC) presents the interplay of executable record with the Oracle database.
It permits the strolling of any packaged or custom constructed utility with the Oracle database that is running on a server pool.
It affords very high level of availability, flexibility and scalability to run the utility and keep it to the database.
It creates the database such that if the pool fails then the database is continued to run from the remaining servers and the load may be disbursed.
It makes it less difficult for the administrator to keep many servers at the same time by means of load-balancing techniques and presenting provision to add increasingly servers when the weight will increase.
Question 2. Where Are The Clusterware Files Stored On A Rac Environment?

Answer :

The Clusterware is hooked up on each node (on an Oracle Home) and at the shared disks (the balloting disks and the CSR document).

PL/SQL Interview Questions
Question 3. What Is Scan?

Answer :

Single Client Access Name (SCAN) is s a new Oracle Real Application Clusters (RAC) 11g Release 2 feature that gives a single call for customers to get entry to an Oracle Database going for walks in a cluster. The advantage is clients using SCAN do not want to change in case you upload or do away with nodes within the cluster.

 

Question 4. What Is Required By Oracle Rac Database To Connect To A Network?

Answer :

Oracle RAC calls for an active connection of the network to the LAN (Local Area Network) so that the database server can be determined and related.
The database server is in addition having connections with software servers that store the programs and allow user to switch their statistics.
The connection is needed with the server pool in order that the switch of services and packages can be done on demand basis.
The interconnection between the networks is definitely vital as it has to maintain the general drift of the pools and the resources.
Oracle RAC offers aid to redundant interconnects fantastically and it presents an overall infrastructure solution.
The load balancing and inter-node messaging may be handled more cautiously when the networks or the servers are interconnected to each different.
Oracle DBA Tutorial
Question 5. How Is Possible To Install A Rac If We Don’t Have A Cfs?

Answer :

This is viable by way of using a raw device.

Oracle DBA Interview Questions
Question 6. What Are The Types Of Connection Load-balancing?

Answer :

There are two forms of connection load-balancing: server-facet load balancing and client-aspect load balancing.

Question 7. What Are The Provisions And Resources Provided In The Oracle’s Cloud Server?

Answer :

Oracle’s cloud server gives scalability with the aid of adding extra servers to a pool whilst there's a demand of any processing power or area.
Provision to pay in line with hour/use as consistent with the requirement, to, hold the overall cost low and construct the capability on the excessive-quit systems.
Oracle RAC gives the platform’s structure because it gives low-value hardware platform to deliver excessive pleasant provider and offer greater scalability and availability.
This reduces the administration fee and offers suitable control strategies and gear to screen the offerings.
This permits the customers to build their personal infrastructure on the premise of cloud.
DB2 Using SQL Tutorial DB2 Using SQL Interview Questions
Question 8. Where Are The Database Software Files Stored On A Rac Environment?

Answer :

The base software program is set up on every node of the cluster and the database garage on the shared disks.

Question 9. What Is Grd?

Answer :

GRD stands for Global Resource Directory. The GES and GCS keep facts of the reputation of each datafile and every cached block the usage of worldwide aid listing. This system is known as cache fusion and helps in information integrity.

RMAN (Recovery Manager) Interview Questions
Question 10. Explain The Hardware Architecture Used In Oracle Rac?

Answer :

The Hardware Architecture of the Oracle RAC clusters gives a shared structure with the server swimming pools and lets in all of the storage gadgets to be shared.
Hardware Architecture supports exclusive types of garage networks like Network attached garage (NAS), Storage Area Network (SAN) and SCSI disks.
Hardware architecture is such that it offers appropriate alternatives for the storage swimming pools and gadget that provides scalability and flexibility to the general machine.
The structure should contain the input and output for the software that need to be evolved after which the device can have more scalability.
Hardware structure helps more application to be added inside the server pool and permits better integration of services.
Question 11. Do You Know Another Cluster Vendor?

Answer :

HP Tru64 Unix, Veritas, Microsoft

Oracle E-Bussiness Suite Interview Questions
Question 12. What Are The Performance Views In An Oracle Rac Environment?

Answer :

We have v$ perspectives which might be example precise. In addition we have GV$ perspectives known as as global perspectives that has an INST_ID column of numeric statistics type.GV$ perspectives attain information from character V$ perspectives.

 

PL/SQL Interview Questions
Question 13. What Is The Function Of Cache Fusion In Oracle Rac?

Answer :

Cache characteristic is used to show the garage of the statistics inside the clustered community with the Oracle database.
This makes use of the database switch medium and it entails two nodes wherein one reads the records block from the disk and some other write the facts to the same disk.
It provides superb performance and increases the flexibility in phrases of execution of the application this is the use of the platform.
RAC uses a dedicated server for its community connection and the cache fusion is an inner part to the cluster.
It makes use of the equal database and maintains the matters in the cache till the information isn't always needed anymore by another software. It queries the facts simplest when it absolutely necessary to do it.
The question from the user usually outcomes in the maximum current version even after the records is being changed.
Question 14. What Kind Of Storage We Can Use For The Rac Database Storage?

Answer :

OCFS (Release 1 or 2)
ASM
raw gadgets
1/3 celebration cluster report system consisting of GPFS or Veritas
Question 15. What Is A Crs Resource?

Answer :

Oracle Clusterware is used to manipulate excessive-availability operations in a cluster. Anything that Oracle Clusterware manages is known as a CRS resource. Some examples of CRS sources are database, an example, a provider, a listener, a VIP address, an utility system and so forth.

Oracle MySQL 5.6 Database Administrator Interview Questions
Question sixteen. How Is Clustered Database Important In Oracle Rac Architecture?

Answer :

Clustered database is similar to a unmarried database accessed by means of a couple of instances which can be jogging at the server.
The instances are being run one at a time or personally at the server pool and while the demands upward thrust they're shifted to acquire extra space in line with the requirements.
Clustered database affords dynamic get right of entry to to the database and at the demand of additional assets they're introduced to the server pool.
If one cluster is taking over the load then that load is shared between other clusters strolling on the server and the software offerings are furnished in a much faster and better way.
This additionally permits the including of extra assets dynamically to the server pool with no downtime and the software begins walking soon it's far deployed at the server.
Question 17. What Is An Ocfs2?

Answer :

The OCFS2 is the Oracle (model 2) Cluster File System which can be used for the Oracle Real Application Cluster.

Oracle Exadata Database Interview Questions
Question 18. How Do We Remove Asm From An Oracle Rac Environment?

Answer :

We want to prevent and delete the example in the node first in interactive or silent mode. After that ASM may be eliminated the use of srvctl device as follows:

srvctl prevent asm -n node_name
srvctl do away with asm -n node_name
We can affirm if ASM has been removed with the aid of issuing the following command:
srvctl config asm -n node_name
Oracle DBA Interview Questions
Question 19. Describe The Oracle Real Application Clusters Architecture?

Answer :

Oracle RAC includes a database this is represented in a clustered manner in the architecture.
The cluster is the gathering or pool of unbiased servers that make up one single device.
Cluster structure provides greater flexibility to manage and comply with a modular incremental approach to improve the fault mistakes and offer an incremental device.
This structure offers the maximum security in phrases of making sure high availability of the resources to the customers.
It gives the resources on call for and offers hardware structure such that a single factor of failure is being removed.
The structure offers the decoupling of the Oracle example just like the procedure and reminiscence that are walking at the server from the Oracle database.
Question 20. What Is A Cfs?

Answer :

A cluster File System (CFS) is a file gadget that may be accessed (study and write) through all individuals in a cluster on the equal time. This implies that every one participants of a cluster have the equal view.

Oracle GoldenGate Interview Questions
Question 21. What Is The Use Of Ocr?

Answer :

Oracle Clusterware manages CRS assets based at the configuration information of CRS resources saved in OCR (Oracle Cluster Registry).

Question 22. What Are The Key Components Of Oracle’s Maximum Availability Architecture?

Answer :

Oracle Real Application Clusters are the important thing components of the prevailing structure.
It provides directions and management of the programs that needs to be architect the usage of the architecture.
It gives high scalability of the packages that is being run on a unmarried server and it takes the advantage of decrease value commodity hardware to lessen the fee.
It permits the Oracle database to be run and maintained the usage of the commercial enterprise utility which are at the server swimming pools and entails packaged products as properly.
It affords a manner to combine the in-house applications that are advanced the use of the oracle database and its technology.
It allows smooth management of the server by using presenting the potential to get rid of the server as a unmarried factor of failure inside the database utility surroundings.
Question 23. What Kind Of Storage We Can Use For The Shared Clusterware Files?

Answer :

OCFS (Release 1 or 2)
uncooked gadgets
1/3 party cluster file gadget together with GPFS or Veritas
Oracle DBA Troubleshooting Interview Questions
Question 24. How Does An Oracle Clusterware Manage Crs Resources?

Answer :

Oracle Clusterware manages CRS sources primarily based at the configuration statistics of CRS sources stored in OCR (Oracle Cluster Registry).

DB2 Using SQL Interview Questions
Question 25. What Is Asm?

Answer :

               In Oracle Database 10g/11g there are  styles of times: database and ASM instances. The ASM instance, that is normally named +ASM, is commenced with the INSTANCE_TYPE=ASM init.Ora parameter. This parameter, while set, alerts the Oracle initialization recurring to start an ASM example and now not a widespread database instance. Unlike the usual database example, the ASM example contains no physical files; together with logfiles, controlfiles or datafiles, and best requires some init.Ora parameters for startup.
               Upon startup, an ASM instance will spawn all the simple background techniques, plus a few new ones which are precise to the operation of ASM. The STARTUP clauses for ASM instances are much like those for database instances. For instance, RESTRICT prevents database times from connecting to this ASM instance. NOMOUNT starts offevolved up an ASM instance with out mounting any disk organization. MOUNT choice virtually mounts all defined diskgroups
              For RAC configurations, the ASM SID is +ASMx instance, wherein x represents the example number.

Question 26. What Are The Key Benefits Of Asm?

Answer :

ASM offers filesystem and extent supervisor abilties constructed into the Oracle database kernel. Withthis capability, ASM simplifies garage control obligations, along with developing/laying out databases and disk area management. Since ASM lets in disk control to be finished using acquainted create/regulate/drop SQL statements, DBAs do no longer want to research a brand new talent set or make vital selections on provisioning.
The following are a few key blessings of ASM:

ASM spreads I/O frivolously throughout all to be had disk drives to save you warm spots and maximize performance.
ASM removes the want for over provisioning and maximizes storage resource utilization facilitating database consolidation.
Inherent big file aid.
Performs automated on line redistribution after the incremental addition or elimination of garage  capability.
Maintains redundant copies of data to provide high availability, or leverages 3rd birthday party RAID functionality.
Supports Oracle Database in addition to Oracle Real Application Clusters (RAC).
Capable of leveraging 3rd celebration multipathing technology.
For simplicity and less complicated migration to ASM, an Oracle database can contain ASM and non-ASM documents.
Any new documents can be created as ASM documents even as current documents can also be migrated to ASM.
RMAN commands permit non-ASM managed files to be relocated to an ASM disk institution.
Enterprise Manager Database Control or Grid Control may be used to manage ASM disk and file sports.
 

Oracle Data Guard Interview Questions
Question 27. How Does Database Connects To Asm Instance?

Answer :

The database communicates with ASM instance using the ASMB (umblicus process) system. Once the database obtains the vital extents from volume map, all database IO going  forward is processed through by using the database procedures, bypassing ASM. Thus we say ASM is not clearly in the IO direction. So, the question how will we make ASM pass faster…..You don’t have to.

RMAN (Recovery Manager) Interview Questions
Question 28. What Init.Ora Parameters Does A User Need To Configure For Asm Instances?

Answer :

The default parameter settings paintings perfectly for ASM. The simplest parameters wanted for 11g ASM:

PROCESSES*
ASM_DISKSTRING*
ASM_DISKGROUPS
INSTANCE_TYPE
Question 29. How Does The Database Interact With The Asm Instance And How Do I Make Asm Go Faster?

Answer :

ASM is not inside the I/O route so ASM does not impede the database document access. Since the RDBMS instance is performing raw I/O, the I/O is as fast as possible.

Question 30. Do I Need To Define The Rdbms Filesystemio_options Parameter When I Use Asm?

Answer :

No. The RDBMS does I/O directly to the raw disk devices, the FILESYSTEMIO_OPTIONS  parameter is most effective for filesystems.

Question 31. Why Oracle Recommends Two Disk Groups?

Answer :

Oracle recommends two diskgroups to provide a stability of manageability, utilization, and overall performance.

 

Question 32. We Have A sixteen Tb Database. I’m Curious About The Number Of Disk Groups We Should Use; E.G. 1 Large Disk Group, A Couple Of Disk Groups, Or Otherwise?

Answer :

For VLDBs you'll probably emerge as with exceptional garage levels; e.G with some of our large customers they've Tier1 (RAID10 FC), Tier2 (RAID5 FC), Tier3 (SATA), etc. Each this sort of is mapped to a diskgroup.

Question 33. We Have A New App And Don’t Know Our Access Pattern, But Assuming Mostly Sequential Access, What Size Would Be A Good Au Fit?

Answer :

For 11g ASM/RDBMS it is endorsed to use 4MB ASM AU for disk companies. See Metalink Note 810484.1

Oracle E-Bussiness Suite Interview Questions
Question 34. Would It Be Better To Use Bigfile Tablespaces, Or Standard Tablespaces For Asm?

Answer :

The use of Bigfile tablespaces has no touching on ASM (or vice versa). In reality maximum database item related choices are obvious to ASM.

Question 35. What Is The Best Lun Size For Asm?

Answer :

There is no fine length! In most cases the garage team will dictate to you primarily based on their standardized LUN length. The ASM administrator merely has to talk the ASM Best Practices and alertness  characteristics to garage oldsters :
• Need equally sized / overall performance LUNs
• Minimum of four LUNs
• The capacity requirement
• The workload characteristic (random r/w, sequential r/w) & any reaction time SLA
Using this information , and their standards, the garage parents need to construct a nice LUN group set for you.

 

Question 36. In 11g Rac We Want To Separate Asm Admins From Dbas And Create Different Users And Groups. How Do We Set This Up?

Answer :

For rationalization
• Separate Oracle Home for ASM and RDBMS.
• RDBMS instance connects to ASM the use of OSDBA group of the ASM instance.
Thus, software proprietor for each RDBMS instance connecting to ASM ought to be a member of ASM's OSDBA organization.
• Choose a distinctive OSDBA organization for ASM instance (asmdba) than for RDBMS instance (dba)
• In 11g, ASM administrator must be member of a separate SYSASM institution to separate ASM Admin and DBAs.

Oracle MySQL 5.6 Database Administrator Interview Questions
Question 37. Can My Rdbms And Asm Instances Run Different Versions?

Answer :

Yes. ASM can be at a higher version or at decrease model than its client databases. There’s two:
additives of compatiblity: Software compatibility
Diskgroup compatibility attributes: compatible.Asm, well suited.Rdbms.

Question 38. Where Do I Run My Database Listener From; I.E., Asm Home Or Db Home?

Answer :

It is suggested to run the listener from the ASM HOME. This is mainly critical for RAC env, for the reason that listener is a node-stage resource. In this config, you can create additional [user] listeners from the database homes as wished.

 

Question 39. How Do I Backup My Asm Instance?

Answer :

Not applicable! ASM has no files to backup, as its does no longer comprise controlfile,redo logs etc.

Question 40. When Should I Use Rman And When Should I Use Asmcmd Copy?

Answer :

RMAN is the endorsed and maximum entire and flexible technique to backup and delivery database files in ASM.
ASMCMD copy is ideal for copying unmarried files
• Supports all Oracle document kinds
• Can be used to instantiate a Data Guard environment
• Does now not replace the controlfile
• Does not create OMF documents

Oracle Exadata Database Interview Questions
Question forty one. I'm Going To Do Add Disks To My Asm Diskgroup, How Long Will This Rebalance Take?

Answer :

Rebalance time is heavily pushed via the three items:
1) Amount of information currently within the diskgroup
2) IO bandwidth available on the server
3) ASM_POWER_LIMIT or Rebalance Power Level

Question forty two. We Are Migrating To A New Storage Array. How Do I Move My Asm Database From Storage A To Storage B?

Answer :

Given that the brand new and antique storage are both seen to ASM, truly add the new disks to the ASM disk group and drop the antique disks. ASM rebalance will migrate records online.


Oracle GoldenGate Interview Questions
Question forty three. Is It Possible To Unplug An Asm Disk Group From One Platform And Plug Into A Server On Another Platform (for Example, From Solaris To Linux)?

Answer :

No. Cross-platform disk institution migration no longer supported. To move datafiles among endian-ness structures, you want to use XTTS, Datapump or Streams.

Question forty four. How Does Asm Work With Multipathing Software?

Answer :

It works brilliant! Multipathing software program is at a layer lower than ASM, and accordingly is transparent.
You might also need to modify ASM_DISKSTRING to specify only the direction to the multipathing pseudo devices.

Question forty five. Is Asm Constantly Rebalancing To Manage “hot Spots”?

Answer :

No.ASM gives even distribution of extents across all disks in a disk organization. Since every disk will same variety of extents, no unmarried disk might be warmer than every other. Thus the answer NO, ASM does now not dynamically move warm spots, because hot spots truely do not arise in ASM configurations. Rebalance only happens on storage configuration changes (e.G. Add, drop, or resize disks).

 

Question 46. What Are The File Types That Asm Support And Keep In Disk Groups?

Answer :

Control documents
Flashback logs
Data Pump dump units
Data documents
DB SPFILE
Data Guard configuration
Temporary records documents
RMAN backup units
Change monitoring bitmaps
Online redo logs
RMAN statistics document copies
OCR documents
Archive logs
Transport facts files
ASM SPFILE
Question forty seven. List Key Benefits Of Asm?

Answer :

Stripes documents in place of logical volumes
Provides redundancy on a file foundation
Enables on-line disk reconfiguration and dynamic rebalancing
Reduces the time extensively to resynchronize a temporary failure by tracking modifications while disk is offline
Provides adjustable rebalancing pace
Is cluster-conscious
Supports studying from mirrored reproduction in place of number one reproduction for prolonged clusters
Is routinely mounted as part of the Grid Infrastructure
Question forty eight. What Is Asm Striping?

Answer :

ASM can use variable length data extents to assist larger files, reduce memory necessities, and enhance performance.
Each records extent resides on an individual disk.
Data extents consist of one or greater allocation devices.
The information extent size is:

Equal to AU for the primary 20,000 extents (zero–19999)
Equal to 4 × AU for the following 20,000 extents (20000–39999)
Equal to 16 × AU for extents above 40,000
ASM stripes documents the usage of extents with a coarse approach for load balancing or a quality method to reduce latency.

Coarse-grained striping is constantly same to the effective AU size.
Fine-grained striping is constantly identical to 128 KB.
Question 49. How Many Asm Diskgroups Can Be Created Under One Asm Instance?

Answer :

ASM imposes the following limits:

sixty three disk agencies in a storage gadget
10,000 ASM disks in a storage device
Two-terabyte maximum storage for each ASM disk (non-Exadata)
Four-petabyte maximum garage for each ASM disk (Exadata)
40-exabyte most storage for each storage device
1 million documents for every disk group
ASM document size limits (database limit is 128 TB):
External redundancy most report size is 140 PB.
Normal redundancy maximum record size is 42 PB.
High redundancy maximum file length is 15 PB.
Question 50. What Is A Diskgroup?

Answer :

A disk organization consists of multiple disks and is the fundamental item that ASM manages. Each disk group includes the metadata this is required for the control of area within the disk group. The ASM example manages the metadata approximately the documents in a Disk Group within the identical way that a report system manages metadata about its documents. However, the giant majority of I/O operations do not pass via the ASM example. In a second we can take a look at how report I/O works with appreciate to the ASM instance.




CFG