Linux Services

Service Name ntpd Description This service executes the Network Time Protocol (NTP) daemon ntpd. The purpose is to synchronize the time of the local computer to a NTP server or other reference time source such as a radio or satellite receiver or modem. The NTP time protocol provides accuracies typically within a millisecond on LANs and up to a few tens of milliseconds on WANs relative to Coordinated Universal Time (UTC) via a Global Positioning Service (GPS) receiver. The Linux NTP package … [Read more...] about Linux OS Service ‘ntpd’

Service Name microcode_ctl Description microcode_ctl updates a microcode in IA32 CPU. The microcode is prepared as a file /etc/firmware/microcode.dat. As this service can fix microcode bugs by updating CPU microcode this should be available.m however only for Intel IA32. Basically, running "service microcode_ctl start" doesn't start up a daemon, it first checks if the processor is suitable for updating firmware, if it is, then "microcode_ctl" service will insert the module "microcode" … [Read more...] about Linux OS Service ‘microcode_ctl’

Service Name nfs Description The Network File System (NFS) is a server/client based networking protocol. NFS daemons are composed by nfsd, rpc.mountd, rpc.rquotad, rpc.lockd. 1. nfsd: nfsd handles client requests from remote systems. Multiple copies of this daemon are usually run so that several requests can be handled simultaneously. However, too many copies of nfsd can increase the demand for CPU time to the point where a drop in performance results. For the best performance the … [Read more...] about Linux OS service ‘nfs’

Service Name network Description The 'network' service activates or deactivates all network interfaces configured to start at boot time. The traditional TCP/IP v4 networking is always enabled if networking is used. The newer TCP/IP v6 may be selectively enabled here. The default system hostname is also provided here but may be later changed as individual network interfaces are started. Individual network interfaces, often referred to as a "NIC", each have a configuration file in the … [Read more...] about Linux OS Service ‘network’

Service Name portmap Description Portmap service maps RPC requests to the correct services. RPC processes notify portmap when they start, revealing the port number they are monitoring and the RPC program numbers they expect to serve. The client system then contacts portmap service on the server with a particular RPC program number. portmap then redirects the client to the proper port number to communicate with its intended service. This service executes portmap daemon and portmap service … [Read more...] about Linux OS service ‘portmap’

Service Name auditd Description auditd is the userspace component to the Linux Auditing System. It’s responsible for writing audit records to the disk. Viewing the logs is done with the ausearch or aureport utilities. Configuring the audit rules is done with the auditctl utility. During startup, the rules in /etc/audit.rules are read by auditctl. The audit daemon itself has some configuration options that the admin may wish to customize. They are found in the auditd.conf file. The Linux … [Read more...] about Linux OS service ‘auditd’

Service Name iptables Description The iptables utility controls the network packet filtering code in the Linux kernel. If you need to set up firewalls and/or IP masquerading, you should install this tool. The /sbin/iptables application is the userspace command line program used to configure the Linux IPv4 packet filtering rules. Since Network Address Translation (NAT) is also configured from the packet filter rules, /sbin/iptables is used for this, too. There is a similar tool for IPv6 … [Read more...] about Linux OS Service ‘iptables’

Service Name dhcpd Description - The Dynamic Host Configuration Protocol (DHCP), a derivation of the original Bootstrap Protocol (BOOTP), has expanded its usefulness beyond its thin-client origins. Enterprise-level systems often use the DHCP service to centralize the administration of TCP/IP addresses, network masks, hostnames, router and DNS information. - The dhcpd service is run on the DHCP server. Upon booting, DHCP client machines broadcast queries for information which are then … [Read more...] about Linux OS service ‘dhcpd’

Service Name anacron Cron Vs Anacron Similar to the cron service, the anacron service runs applications or scripts at specific times and dates. This allows for reliable unattended system operation - scheduled events are not missed if the system goes down - instead, they are run as soon as possible after their scheduled time. Candidates for an anacron action are often system administration activies, such as log rotation, that must be performed, even if late. Unlike the cron service, … [Read more...] about Linux OS Service ‘anacron’

Service Name iscsid Description The iscsid (Internet Small Computer Systems Interface) service implements the control path of iSCSI protocol, plus some management facilities. For example, the daemon could be configured to automatically re-start discovery at startup, based on the contents of the persistent iSCSI database. ISCSI is a protocol to access remote SCSI disks via the network. The major and huge storage devices, like HITACHI SANRISE or EMC, have the function of an iSCSI server - … [Read more...] about Linux OS service ‘iscsid’