NFS-NIS.ppt
- 1. Network Information Services (NIS) Network File System (NFS)
- 2. What is NIS? • Problems in running a distributed computing environment : – Each Workstations has its own copies of common configuration files such as passwd, group, and hosts files – These files must be consistent and every changes to these common files much be propagated to every hosts on the network
- 3. What is NIS? ?? Lo g o n Fa ilu re !!
- 4. What is NIS? • The NIS, released by Sun in 1980s, was the first “prime time” administrative database to address these problems. • It was originally called the Sun Yellow Pages, but eventually had to be renamed for legal reasons. Many vendors have licensed Sun’s code, making NIS the most widely- supported network database system
- 5. What is NIS? • It is a distributed database system that replaces copies of commonly replicated configuration files with a centralized management facility • Instead of having to manage each host’s files, you maintain one database for each file on one central server
- 6. NIS Masters, Slaves, and Clients NIS MASTER SERVER NIS SLAVE SERVER NIS SLAVE SERVER CLIENT CLIENT CLIENT CLIENT
- 7. NIS Servers • An NIS server is a machine storing a set of maps that are available to network machines and applications. • NIS master server – contains the set of maps that you, the NIS administrator, create and update as necessary. – Each NIS domain must have one, and only one, master server.
- 8. NIS Servers • NIS Slave server – A slave server has a complete copy of the master set of NIS maps. Whenever the master server maps are updated, the updates are propagated among the slave servers. The existence of slave servers allows the system administrator to evenly distribute the load resulting from answering NIS requests. It also minimizes the impact of a server becoming unavailable.
- 9. NIS Elements • NIS Domains – An NIS domain is a collection of machines that share a common set of NIS maps. Each domain has a domain name and each machine sharing the common set of maps belongs to that domain. – Domain names are case-sensitive.
- 10. NIS Elements • NIS Maps – NIS maps are essentially two-column tables. One column is the key and the other column is information value related to the key. NIS finds information for a client by searching through the keys. Some information is stored in several maps because each map uses a different key.
- 11. NIS Elements – Maps for a domain are located in each server's /var/yp/domainname directory. – For example, the maps that belong to the domain test.com are located in each server's /var/yp/test.com directory. – An NIS Makefile is stored in the /var/yp directory of machines designated as a NIS server at installation time. Running make in that directory causes makedbm to create or modify the default NIS maps from the input files.
- 12. NIS Elements • NIS daemons Daemon Functions ypserv Server process ypbind Binding process ypxfrd High speed map transfer rpc.yppasswdd NIS password update daemon
- 13. NIS Query
- 14. NIS Query Application ypbind C Library getpwuid C Library ndbm ypserv The Filesystem Client Side Server Side
- 15. Basic NIS Management • Installing a new NIS Environment, building Master and slave servers • Starting the ypserv daemon, which enables the system to act as NIS Server • Adding new slave servers when growth of your network • Modifying the client’s administrative files • Starting the ypbind daemon, allowing the client to make NIS requests • Ypbind, yppasswdd , ypserv, portmap, ypbind ,ypxfrd NIS server services • Ypbind & portmap are NIS client services
- 16. Building NIS Master Server NIS Sever Local /etc/passwd Local /etc/shadow NIS Passwd map source file : say passwd.yp root/system local logon normal user local logon through NIS (if permitted) ypserv ypbind
- 17. Enabling NIS on client • Start the ypbind daemon, which is responsible for locating NIS servers and maintaining bindings of domain names to servers
- 18. Changing Password in NIS NISMaster Server N IS S la ve S e rve r Map propagation NIS Request Request to changepassord (useyppasswd)
- 19. Merits of NIS • Simple, easy to understand. It’s analogous to copying files around; in most cases, it’s unnecessary for administrators to be aware of NIS’ internal data formats • Widely supported by multiple vendors like DEC, HP, SGI.
- 20. Network File System (NFS)
- 21. What is NFS? • The Network File System, allows you to share filesystems among computers. • NFS is almost transparent to users. • NFS was introduced by Sun in 1985. It was originally implemented as a surrogate filesystem for diskless clients.
- 22. What is NFS? • NFS support has been implemented on many platforms ranging from the MS-DOS to the VMS operating systems. Many use code licensed from Sun.
- 23. Benefits of NFS – Allows multiple computers to use the same files, so everyone on the network can access the same data – Reduces storage costs by having computers share applications instead of needing local disk space for each user application – Provides data consistency and reliability because all users can read the same set of files – Makes mounting of file systems transparent to
- 24. Benefits of NFS – Makes accessing remote files transparent to users – Supports heterogeneous environments – Reduces system administration overhead
- 25. NFS Elements rpc.nfsd The Filesystem C lient Side Server Side /etc/ exports rpc.mountd mount command User credentials (UID, {GIDs}) /etc/mtab /etc/rmtab