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This article mainly introduces the relevant knowledge of what to prepare after the server relocation, the content is detailed and easy to understand, the operation is simple and fast, and has a certain reference value. I believe you will gain something after reading this server relocation work article. Let's take a look at it.

one

Batch test the available status of the server

If a large number of servers are relocated, some can be connected and some cannot, there is a hard wound in using telnet itself. We can directly set a timeout to see whether the service is available at a glance. The nc command is still recommended at this time. For example, to test whether port 22 of server 10.129.128.37 is reachable and the timeout is 2 seconds, you can use the following command.

Nc-z-v-n-w 2 10.129.128.37 22

two

Check the connection of ILO

If ILO (iDRAC) is not available, then your server is basically guaranteed to be unavailable. Without the ultimate control, even if you can connect, but once the server has an exception, it is completely out of control. At this time, pay special attention to the password, to know the password.

three

Check the root password

The importance of checking root passwords is self-evident. If you can access the server, but you can't log in at all, and you don't have any intended users, then this can also give the server a "sentence". Changing the root password itself is not an easy task, through various settings, if you need a password at a critical step.

four

Firewall information lost

This situation has been encountered several times, and the connection that could have been connected to the server after the server restart can no longer be connected. At this time, the solution is to connect to the server by ILO, and then open it manually, or leave yourself some leeway to open the access permission for the main database or slave database. In this way, even if the central control permission is lost, you can still ensure that you can connect.

five

Use hard IP binding instead of host domain binding

Some systems will set auto-startup listening, and it is very likely that the server cannot enable self-startup. One of the main reasons is the use of hard IP binding. It will be much easier to use host domain name resolution in listener.ora.

Or for mysql, this problem will be magnified. For example, after a slave server is started, it is unable to connect to the main database application binlog. After troubleshooting, one of the main reasons is that the hard IP configuration is used for the configuration of user permissions, which is much more convenient if you use domain name binding.

The error message for slave is as follows:

2017-07-26 03:55:34 2490 [ERROR] Slave I retry-time O: error connecting to master 'rep_live800@live800.test.com:3306'-retry-time: 5 retries: 5, Error_code: 1130

2017-07-26 03:55:39 2490 [ERROR] Slave I retry-time O: error connecting to master 'rep_live800@live800.test.com:3306'-retry-time: 5 retries: 6, Error_code: 1130

Update mysql.user set host='xxxx' where user='xxx'

At this time, refresh permissions can connect normally.

-- flush privileges

View the log of slave as follows:

2017-07-26 03:55:44 2490 [Note] Slave I O thread: connected to master 'rep_live800@live800.test.com:3306',replication started inlog' binlog.000019' at position 818554844

six

The configuration of the tool

If you use oracle's DG broker configuration, you are likely to have some problems if you have some configuration problems or if DG Broker is not powerful enough in earlier versions.

For example, the following DG Broker configuration always fails, which is the problem, and finally reconfigure DG Broker.

Data Guard Broker terminating NSV3, timed out waiting for a response from database s3accdb0

07/26/2017 09:13:18

Data Guard Broker terminating NSV3, timed out waiting for a response from database s3accdb0

07/26/2017 09:13:37

seven

The database cannot be started

The database is likely to fail at startup, possibly because of the zombie process, or because of kernel parameter configuration problems. For example, the following question.

Idle > startup mount

ORA-27102: out of memory

Linux-x86_64 Error: 28: No space left on device

The reason for the error is that the zombie process in memory still exists and has not been released.

$ps-ef | grep smon

Oracle 5374 4967 0 12:58 pts/0 00:00:00 grep smon

Oracle 24710 10 Jul25? 00:00:00 ora_smon_statdb1

Release it manually and restart it.

eight

Database file is missing

Database if you start the server and suddenly find that all the data is lost and sqlplus,mysql is completely unavailable, don't worry, you can see if the partition is not mounted.

This is the end of the article on "what to prepare for after the server relocation". Thank you for your reading. I believe you all have a certain understanding of the knowledge of "what to prepare for after the server relocation". If you still want to learn more knowledge, you are welcome to follow the industry information channel.

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