BCV (Business Continuance Volume ) is the target volume for EMC Symmetrix TimeFinder/Mirror process. When a BCV is fully synchronized with a data device, the BCV is separated or split, thus becomes available to a host for backup or other host processes. In short, a BCV split is a device to be a clone of […]
Archives for November 2019
How to change the interface name in CentOS/RHEL 8 using prefixdevname
This post will help to change the network interface name using prefixdevname utility in CentOS/RHEL 8 systems. Installation and configuration 1. Install the required package using dnf utility: # dnf install prefixdevname 2. Append the net.ifnames.prefix=[ABCD] using grubby command: (ABCD to replaced with own prefix, eg: net). # grubby –update-kernel=$(grubby –default-kernel) –args=”net.ifnames.prefix=net” 3. Reboot the […]
Beginners Guide to Implementing Table Maintenance in MySQL
Table maintenance operations are useful for identifying and correcting database problems such as the following: – Tables that become damaged as a result of a server crash. – Slow query processing on tables. Many tools are available for performing table maintenance: MySQL Workbench MySQL Enterprise Monitor SQL (DML) maintenance statements Utilities: mysqlcheck and myisamchk Server […]
MySQL – How to Set Maximum Rates for Connections and Queries
There are several options to implement firewall like features for a MySQL instance. Some of these are described below. When an account is mentioned it refers to the combination of a username connected from a given host, i.e. username@hostname. MySQL Enterprise Firewall MySQL Enterprise Firewall will allow you to create a whitelist per account specifying […]
How to configure EPEL repository in OEL 7
Question: How to install/get packages from EPEL Repository on OEL 7? 1. Create a repo file like /etc/yum/repos.d/epel-yum-ol7.repo. For example: # cat /etc/yum.repos.d/epel-yum-ol7.repo [ol7_epel] name=Oracle Linux $releasever EPEL ($basearch) baseurl=http://yum.oracle.com/repo/OracleLinux/OL7/developer_EPEL/$basearch/ gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle gpgcheck=1 enabled=1 2. And then run “yum repolist” command to see if repository is in there. # yum repolist Loaded plugins: langpacks repo id […]
MySQL: How to Set Account Resource Limits
Limit the use of server resources by setting the global MAX_USER_CONNECTIONS variable to a non-zero value. This limits the number of simultaneous connections by any one account but does not limit what a client can do when connected. To set resource limits for an account, use the GRANT statement with a WITH clause that names […]
MySQL ‘show processlist’ statement
You can also get thread information from the INFORMATION_SCHEMA.PROCESSLIST table or the mysqladmin processlist command. If you do not have the PROCESS privilege, you can view only your own threads. That is, you can view only those threads associated with the MySQL account that you are using. If you do not use the FULL keyword, […]
Understanding the REVOKE statement in MySQL
The REVOKE command is used to rescind privileges previously granted to a user. Its syntax is: REVOKE priv_type [(column_list)] [, priv_type [(column_list)] …] ON {tbl_name | * | *.* | db_name.*} FROM user_name [, user_name …] As is the case with the GRANT command, perhaps the best way to really understand how it operates is […]
MySQL Grants – Setting User Permissions On Different Tables
Question: How to set a user, read-only permission for few tables, and alter/insert/delete permission for the rest of the tables? This can be achieved using MySQL grant’s, as MySQL do allow to allow/revoke privileges at a table level. Normally, a database administrator first uses CREATE USER to create an account, then GRANT to define its […]
Excluding a table or database from MySQL replication
This post discusses how to use replication filters to ignore a table or a database in replication. MySQL both have replication filters that explicitly allows and excludes replication of a database or a table from replicating. In this case, you will need to use the filters that ignore. There are three replications filters that can […]