Ques 1: - What is the location of postfix mailserver Queue ?
Ans: - By default, the Postfix mail queues are located in the /var/spool/postfix directory. Each message queue is created as a separate subdirectory within this directory. Each message is stored as a separate file in the subdirectory, using a unique identifier for the filename.
Ques 2: - What is LMTP ?
Ans: - The Local Mail Transport Protocol (LMTP) is a different mail transport protocol described in RFC 2033. LMTP utilizes a set protocol similar to SMTP for delivering messages to the local host. Postfix can be configured to deliver messages to local users using LMTP if desired
Ques 3: - What is Digital Signatures ?
Ans: - Digital signature is an attachment to an electronic message used for security purpose. It is used to verify the authenticity of the sender.
Ques 4: - What is clusterring and why we use clustering ?
Ans: - The concept of a cluster is that the cluster itself appears on the outside as a single system. A cluster consists of two or more Real Computers referred to as nodes or members of a cluster. The components of a cluster are commonly, but not always, connected to each other through fast Local Area Networks.
Clusters are usually deployed to improve performance and/or availability over that provided by a single computer, while typically being much more cost-effective than single computers of comparable speed or availability. Clustering is all about the back-end operations being performed by the nodes or members which appear to the outside world as a single computational entity.
Ques 5: - What is High Availabilty Clusters (HA) ?
Ans: -High-availability clusters provide continuous availability of services by eliminating single points of failure and by failing over services from one cluster node to another in case a node becomes inoperative.High-availability clusters are sometimes referred to as failover clusters. Red Hat Cluster Suite provides high-availability clustering through its High-availability Service Management component.
Ques 6: - What is the Public Key Encryption?
Ans: - Public key encryption use public and private key for encryption and decryption. In this mechanism, public key is used to encrypt messages and only the corresponding private key can be used to decrypt them. To encrypt a message, a sender has to know recipient's public key.