The xendomains service automatically starts, stops, and migrates Oracle VM clients (domU) as the Oracle VM server (dom0) boots or shuts down. In essence, the xendomains service automatically issues a series of xm commands to ensure the proper Oracle VM clients are started and stopped as the dom0 server is started or stopped. No daemons […]
Archives for March 2018
Linux OS Service ‘ldap’
Linux provides both server-side and client-side support for the Lightweight Directory Access Protocol (LDAP) facility. This is a standards-based facility, so it is compatible with other LDAP implementations, including Microsoft’s Active Directory. Data suitable for a directory service has low volatility as LDAP is optimized for read-mostly access; database systems are tailored for more volatile […]
Linux OS Service ‘yppasswdd’
The yppasswdd service executes the yppasswdd daemon. The yppasswdd is a part of NIS (Network Information Service formerly Yellow Pages) server. This server allows users to change their password on a NIS server from a NIS client. The service must be run on the NIS master server for that NIS domain in conjunction with ypserv, […]
How to create and mount filesystems in Linux
File System Types Creating a file system writes information to the device and creates order of the empty space. This file system–related data consumes a small percentage of the space. The remaining space on the disk drive is split into small, consistently sized segments called blocks. Linux supports a number of file system types, some […]
Sample /etc/mke2fs.conf file
Below is a sample /etc/mke2fs.conf file from an CentOS 7 system. # cat /etc/mke2fs.conf [defaults] base_features = sparse_super,filetype,resize_inode,dir_index,ext_attr default_mntopts = acl,user_xattr enable_periodic_fsck = 0 blocksize = 4096 inode_size = 256 inode_ratio = 16384 [fs_types] ext3 = { features = has_journal } ext4 = { features = has_journal,extent,huge_file,flex_bg,uninit_bg,dir_nlink,extra_isize,64bit inode_size = 256 } ext4dev = { features […]
Beginners Guide to User and Group Administration in Linux
Each user in Linux has a unique user ID (UID), which is an ordinary integer number, and an associated username. Users log in by using their usernames, but the system uses the associated UIDs. Each user account also has a home directory and a login shell. When users log in, they are placed in their […]
vncserver fails with “Starting VNC server: no displays configured”
Question When I try to start/restart the “vncserver” service, it fails with the below error. # service vncserver restart Starting VNC server: no displays configured Solution Check for the Syntax of the /etc/sysconfig/vncservers file 1. The above error mostly occurs when you syntax error in the vncserver configuration file /etc/sysconfig/vncservers. You can verify if you […]
Linux OS Service ‘named’
The named service executes the DNS (Dynamic Name Service) server daemon. It converts host names to IP addresses and vice versa. There are several different kinds of DNS servers, such as primary server, slave server and cached server etc. Its data is stored in the directory /var/named. The Domain Name System (DNS) is the hierarchical, […]
Understanding /etc/hosts file in Linux
What Is /etc/hosts And Why Is It Used? In order to send network traffic to a host, the numeric Internet Protocol (IP) address for that host must be known. The IP address is traditionally written as xxx.xxx.xxx.xxx where each xxx represents a value from 0 to 255, for an IPv4 network address. Computers require these […]
Using vmstat to troubleshoot performance issues in Linux
The vmstat (virtual memory statistics) command allows you to monitor your system’s memory usage. It shows how much virtual memory there is, and how much is free and paging activity. You can observe page-ins and page-outs as they happen. This is extremely useful for detecting shortages of physical memory, which can adversely affect system performance. […]