Sunday, November 8, 2015

Server (HP) not reachable on network “Port was disabled because a pause flood was detected”

Host was not reachable on network. When checked on ILO server is up and running. When I try to ping the server its unresponsive.Host is a blade server, hence suspected an issue with the network module. Therefore, connected virtual connect. Found one of the virtual connect module was degraded. When analysed the HP Virtual connect found an error message stating “Port was disabled because a pause flood was detected”

Further to this when validated the server port assigned to the bay1/bay2 found the status “Not Linked/Pause Flood Detected”. It confirms the issue was caused by pause Flood. In some cases, a flex-10 port can enter into disabled state due to the triggering of “pause-flood”, or network-loop. You can confirm the same port status using Virtual Connect Manager CLI. Connect to Virtual connect using SSH and Execute the below command:
Show port-protect
This would show the blade server that’s in impact. To fix the issue, please execute the below command:
reset port-protect
Verify the port status again using the command “show port-protect” and ensure no port’s protect types are reported as “Pause Flood”.
Another action plan would be to update the Drivers and Firmwares.
You can also disable is using the command listed below
set port-protect pauseFlood=Disabled

Saturday, November 7, 2015

How to Change the Location of the OneDrive Folder in Windows 10

OneDrive is a free online storage service that comes bundled with Windows or Office 365 — it’s deeply integrated into everything in Windows and Office. But what if you want to move the folder to a different drive?
Depending on how big and how many files you’ve synced, your OneDrive folder might take up substantial space on your hard drive, so if you have a second and bigger hard drive in your computer, moving the OneDrive folder makes a lot of sense.
But don’t move it just for the sake of moving it. Only move it if you really have a need to.

Change Location of the OneDrive Folder

Right-click the “OneDrive” icon in the System Tray and select “Settings.” (If you don’t see it, it may be hidden. In that case, click the up arrow button in the system tray to see the hidden icons—including OneDrive).
The OneDrive Settings dialog box appears. From the list of options, select “Unlink OneDrive”.
As soon as you click on the option you will get the Welcome to OneDrive screen with a button to “Get started”.
Now before you configure the settings again, move the contents of the OneDrive folder that were already previously synced. Moving the synced folders will make sure you save on your bandwidth on the files that were already previously synced.
Open File Explorer and navigate to the OneDrive folder (usually in C:\Users\<your username>\OneDrive) and select it. Click on the “Home” tab in the explorer ribbon and select “Move to > Choose location.” Choose the folder location (it can be an external hard too, but you have to keep the drive plugged in all the time, which is not practical) where you need to save your OneDrive files in the future.
Go back to the OneDrive set-up screen, select “Get started,” and sign into OneDrive again. When you sign in, OneDrive will ask you where you want to save folders to with a suggested location (your User folder) already selected. Instead of accepting this suggested location, click “Change”, navigate to the folder you selected for OneDrive and select “OK”.
Once you move the OneDrive folder to a new location, it inherits the folder permissions of the parent folder (or drive if the OneDrive folder is placed at the root directory). You’ll need to update the Windows user permissions to the new OneDrive folder that used to exist on the old folder, or else that folder will be viewable by everyone who uses the machine.
Of course, you can limit what folders you want to sync in Windows 10. OneDrive has a feature called selective sync. It lets you either sync all your files and folders on your OneDrive, or choose specific folders to sync, making them available locally.

Tuesday, November 3, 2015

Oracle RAC Interview Questions/FAQs Part1

What is the use of RAC?

2. What are the prerequisites for RAC setup?

3. What are Oracle Clusterware/Daemon processes and what they do?

ocssd, crsd, evmd, oprocd, racgmain, racgimon
  • Prints
  • New
  • Profiles
  • Mac
  • Clients
  • Manages
  • Info
  • Repository
  • Backupfile
  • Buffers

4. What are the special background processes for RAC (or) what is difference in stand-alone database & RAC database background processes?

5. What are structural changes in 11g R2 RAC?

Grid & ASM are on one home, 
Voting disk & ocrfile can be on the ASM,
By using srvctl, we can mange diskgroups, home, ons, eons, filesystem, srvpool, server, scan, scan_listener, gns, vip, oc4j,

6. What are the new features in 11g (R2) RAC?

Grid & ASM are on one home, 
Voting disk & ocrfile can be on the ASM,
By using srvctl, we can mange diskgroups, home, ons, eons, filesystem, srvpool, server, scan, scan_listener, gns, vip, oc4j,

7. What is cache fusion?

Transferring of data between RAC instances by using private network. Cache Fusion is the remote memory mapping of Oracle buffers, shared between the caches of participating nodes in the cluster. When a block of data is read fromdatafile by an instance within the cluster and another instance is in need of the same block, it is easy to get the block image from the instance which has the block in its SGA rather than reading from the disk.

8. What is the purpose of Private Interconnect?

Clusterware uses the private interconnect for cluster synchronization (network heartbeat) and daemon communication between the clustered nodes. This communication is based on the TCP protocol. RAC uses the interconnect for cache fusion (UDP) and inter-process communication (TCP).

9. What are the Clusterware components?

Voting Disk - Oracle RAC uses the voting disk to manage cluster membership by way of a health check and arbitrates cluster ownership among the instances in case of network failures. The voting disk must reside on shared disk.

Oracle Cluster Registry (OCR) - Maintains cluster configuration information as well as configuration information about any cluster database within the cluster. The OCR must reside on shared disk that is accessible by all of the nodes in your cluster. The daemon OCSSd manages the configuration info in OCR and maintains the changes to cluster in the registry.

Virtual IP (VIP) - When a node fails, the VIP associated with it is automatically failed over to some other node and new node re-arps the world indicating a new MAC address for the IP. Subsequent packets sent to the VIP go to the new node, which will send error RST packets back to the clients. This results in the clients getting errors immediately.
crsd – Cluster Resource Services Daemon
cssd – Cluster Synchronization Services Daemon
evmd – Event Manager Daemon
oprocd / hangcheck_timer – Node hang detector

10. What is OCR file?

RAC configuration information repository that manages information about the cluster node list and instance-to-node mapping information. The OCR also manages information about Oracle Clusterware resource profiles for customized applications. Maintains cluster configuration information as well as configuration information about any cluster database within the cluster. The OCR must reside on shared disk that is accessible by all of the nodes in your cluster. The daemon OCSSd manages the configuration info in OCR and maintains the changes to cluster in the registry.

11. What is Voting file/disk and how many files should be there?

Voting Disk File is a file on the shared cluster system or a shared raw device file. Oracle Clusterware uses the voting disk to determine which instances are members of a cluster. Voting disk is akin to the quorum disk, which helps to avoid the split-brain syndrome. Oracle RAC uses the voting disk to manage cluster membership by way of a health check and arbitrates cluster ownership among the instances in case of network failures. The voting disk must reside on shared disk.

12. How to take backup of OCR file?

#ocrconfig -manualbackup
#ocrconfig -export file_name.dmp
#ocrdump -backupfile my_file
$cp -p -R /u01/app/crs/cdata /u02/crs_backup/ocrbackup/RAC1

13. How to recover OCR file?

#ocrconfig -restore backup_file.ocr
#ocrconfig -import file_name.dmp

14. What is local OCR?


15. How to check backup of OCR files?

#ocrconfig –showbackup

16. How to take backup of voting file?

dd if=/u02/ocfs2/vote/VDFile_0 of=$ORACLE_BASE/bkp/vd/VDFile_0
crsctl backup css votedisk         -- from 11g R2

17. How do I identify the voting disk location?

crsctl query css votedisk

18. How do I identify the OCR file location?

check /var/opt/oracle/ocr.loc or /etc/ocr.loc

19. If voting disk/OCR file got corrupted and don’t have backups, how to get them?

We have to install Clusterware.

20. Who will manage OCR files?

cssd will manage OCR.

Oracle L1 Interview Questions and Answers

Oracle RAC Interview Questions & Answers

1. Where are the Clusterware files stored on a RAC environment?
The Clusterware is installed on each node (on an Oracle Home) and on the shared disks (the voting disks and the CSR file)
2. Where are the database software files stored on a RAC environment?
The base software is installed on each node of the cluster and the
database storage on the shared disks.
3. What kind of storage we can use for the shared Clusterware files?
- OCFS (Release 1 or 2)
- raw devices
- third party cluster file system such as GPFS or Veritas
4. What kind of storage we can use for the RAC database storage?
- OCFS (Release 1 or 2)
- raw devices
- third party cluster file system such as GPFS or Veritas
5. What is a CFS?
A cluster File System (CFS) is a file system that may be accessed (read and write) by all members in a cluster at the same time. This implies that all members of a cluster have the same view.
6. What is an OCFS2?
The OCFS2 is the Oracle (version 2) Cluster File System which can be used for the Oracle Real Application Cluster.
7. Which files can be placed on an Oracle Cluster File System?
- Oracle Software installation (Windows only)
- Oracle files (controlfiles, datafiles, redologs, files described by the bfile datatype)
- Shared configuration files (spfile)
- OCR and voting disk
- Files created by Oracle during runtime
Note: There are some platform specific limitations.
8. Do you know another Cluster Vendor?
HP Tru64 Unix, Veritas, Microsoft
9. How is possible to install a RAC if we don’t have a CFS?
This is possible by using a raw device.
10. What is a raw device?
A raw device is a disk drive that does not yet have a file system set up. Raw devices are used for Real Application Clusters since they enable the sharing of disks.
11. What is a raw partition?
A raw partition is a portion of a physical disk that is accessed at the lowest possible level. A raw partition is created when an extended partition is created and logical partitions are assigned to it without any formatting. Once formatting is complete, it is called cooked partition.
12. When to use CFS over raw?
A CFS offers:
- Simpler management
- Use of Oracle Managed Files with RAC
- Single Oracle Software installation
- Autoextend enabled on Oracle datafiles
- Uniform accessibility to archive logs in case of physical node failure
- With Oracle_Home on CFS, when you apply Oracle patches CFS guarantees that the updated Oracle_Home is visible to all nodes in the cluster.
Note: This option is very dependent on the availability of a CFS on your platform.
13. When to use raw over CFS?
- Always when CFS is not available or not supported by Oracle.
- The performance is very, very important: Raw devices offer best performance without any intermediate layer between Oracle and the disk.
Note: Autoextend fails on raw devices if the space is exhausted. However the space could be added online if needed.
14. What CRS is?
Oracle RAC 10g Release 1 introduced Oracle Cluster Ready Services (CRS), a platform-independent set of system services for cluster environments. In Release 2, Oracle has renamed this product to Oracle Clusterware.
15. What is VIP IP used for?
It returns a dead connection IMMIDIATELY, when its primary node fails. Without using VIP IP, the clients have to wait around 10 minutes to receive ORA-3113: “end of file on communications channel”. However, using Transparent Application Failover (TAF) could avoid ORA-3113.
16. Why we need to have configured SSH or RSH on the RAC nodes?
SSH (Secure Shell,10g+) or RSH (Remote Shell, 9i+) allows “oracle” UNIX account connecting to another RAC node and copy/ run commands as the local “oracle” UNIX account.
17. Is the SSH, RSH needed for normal RAC operations?
No. SSH or RSH are needed only for RAC, patch set installation and clustered database creation.
18. Do we have to have Oracle RDBMS on all nodes?
Each node of a cluster that is being used for a clustered database will typically have the RDBMS and RAC software loaded on it, but not actual data files (these need to be available via shared disk).
19. What are the restrictions on the SID with a RAC database? Is it limited to 5 characters?
The SID prefix in 10g Release 1 and prior versions was restricted to five characters by install/ config tools so that an ORACLE_SID of up to max of 5+3=8 characters can be supported in a RAC environment. The SID prefix is relaxed up to 8 characters in 10g Release 2, see bug 4024251 for more information.
20. Does Real Application Clusters support heterogeneous platforms?
The Real Application Clusters do not support heterogeneous platforms in the same cluster.

21. Are there any issues for the interconnect when sharing the same switch as the public network by using VLAN to separate the network?

RAC and Clusterware deployment best practices suggests that the interconnect (private connection) be deployed on a stand-alone, physically separate, dedicated switch. On big network the connections could be instable.
22. What is the Load Balancing Advisory?
To assist in the balancing of application workload across designated resources, Oracle Database 10g Release 2 provides the Load Balancing Advisory. This Advisory monitors the current workload activity across the cluster and for each instance where a service is active; it provides a percentage value of how much of the total workload should be sent to this instance as well as service quality flag.
23. How many nodes are supported in a RAC Database?
With 10g Release 2, we support 100 nodes in a cluster using Oracle Clusterware, and 100 instances in a RAC database. Currently DBCA has a bug where it will not go beyond 63 instances. There is also a documentation bug for the max-instances parameter. With 10g Release 1 the Maximum is 63.

24. What is the Cluster Verification Utiltiy (cluvfy)?
The Cluster Verification Utility (CVU) is a validation tool that you can use to check all the important components that need to be verified at different stages of deployment in a RAC environment.
25. What versions of the database can I use the cluster verification utility (cluvfy) with?
The cluster verification utility is release with Oracle Database 10g Release 2 but can also be used with Oracle Database 10g Release 1.
26. If I am using Vendor Clusterware such as Veritas, IBM, Sun or HP, do I still need Oracle Clusterware to run Oracle RAC 10g?
Yes. When certified, you can use Vendor Clusterware however you must still install and use Oracle Clusterware for RAC. Best Practice is to leave Oracle Clusterware to manage RAC. For details see Metalink Note 332257.1 and for Veritas SFRAC see 397460.1.
27. Is RAC on VMWare supported?
28. What is hangcheck timer used for ? 
The hangcheck timer checks regularly the health of the system. If the system hangs or stop the node will be restarted automatically.
There are 2 key parameters for this module:
-> hangcheck-tick: this parameter defines the period of time between checks of system health. The default value is 60 seconds; Oracle recommends setting it to 30seconds.
-> hangcheck-margin: this defines the maximum hang delay that should be tolerated before hangcheck-timer resets the RAC node.
29. Is the hangcheck timer still needed with Oracle RAC 10g?
30. What files can I put on Linux OCFS2?
For optimal performance, you should only put the following files on Linux OCFS2:
- Datafiles
- Control Files
- Redo Logs
- Archive Logs
- Shared Configuration File (OCR)
- Voting File
31. Is it possible to use ASM for the OCR and voting disk?
No, the OCR and voting disk must be on raw or CFS (cluster file system).
32. Can I change the name of my cluster after I have created it when I am using Oracle Clusterware?
No, you must properly uninstall Oracle Clusterware and then re-install.
33. What the O2CB is?
The O2CB is the OCFS2 cluster stack. OCFS2 includes some services. These services must be started before using OCFS2 (mount/ format the file systems).
34. What the OCR file is used for? 
OCR is a file that manages the cluster and RAC configuration.
35. What the Voting Disk file is used for? 
The voting disk is nothing but a file that contains and manages information of all the node memberships.
36. What is the recommended method to make backups of a RAC environment?                          RMAN to make backups of the database, dd to backup your voting disk and hard copies of the OCR file.
37.  What command would you use to check the availability of the RAC system?
crs_stat -t -v (-t -v are optional)
38. What is the minimum number of instances you need to have in order to create a RAC?
You can create a RAC with just one server.
39.  Name two specific RAC background processes
RAC processes are: LMON, LMDx, LMSn, LKCx and DIAG.
40.  Can you have many database versions in the same RAC?
Yes, but Clusterware version must be greater than the greater database version.
41.  What was RAC previous name before it was called RAC?OPS: Oracle Parallel Server
42.  What RAC component is used for communication between instances?Private Interconnect.
43.  What is the difference between normal views and RAC views?A RAC view has the prefix ‘G’. For example, GV$SESSION instead of V$SESSION
44.  Which command will we use to manage (stop, start) RAC services in command-line mode?
45.  How many alert logs exist in a RAC environment?
A- One for each instance.
46. What are Oracle Clusterware Components
Voting Disk — Oracle RAC uses the voting disk to manage cluster membership by way of a health check and arbitrates cluster ownership among the instances in case of network failures. The voting disk must reside on shared disk.
Oracle Cluster Registry (OCR) — Maintains cluster configuration information as well as configuration information about any cluster database within the cluster. The OCR must reside on shared disk that is accessible by all of the nodes in your cluster
47. How do you backup voting disk
#dd if=voting_disk_name of=backup_file_name
48. How do I identify the voting disk location
#crsctl query css votedisk
49. How do I identify the OCR file location
check /var/opt/oracle/ocr.loc or /etc/ocr.loc ( depends upon platform)
50. What is SCAN?
Single Client Access Name (SCAN) is s a new Oracle Real Application Clusters (RAC) 11g Release 2 feature that provides a single name for clients to access an Oracle Database running in a cluster. The benefit is clients using SCAN do not need to change if you add or remove nodes in the cluster.

Google SMTP Server – How to Send Emails for Free

Google's GMail SMTP server is a free service for anyone who has a GMail account. You can use this free SMTP server to send emails from your favourite web application.
If you don’t have a GMail account, you can create one at the GMail account creation page.
Then all you need to do is configure your mail client to use GMail for outgoing mail server. The details you should use are:
Outgoing Mail (SMTP)
Use AuthenticationYes
Use Secure ConnectionYes (this can be TLS or SSL depending on your mail client)
Usernameyour GMail account, i.e.
Passwordyour GMail password
Port465 or 587
In case you use Google Apps with your domain name and you have created email accounts inside, you should use email account with the Username: field, i.e.
The same email settings can be used with the email functionality of website application such as Joomla, PrestaShop etc. If you have any troubles configuring your website applications with the above settings you can contact the SiteGround Technical Support team and they will be glad to assist you.

Setting up your email is easy when you have the right host by your side. If you need a reliable partner to help you resolve email issues and provide expert support, check out our email hosting services.