P

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PAM (Pluggable Authentication Module)

PAM separates the authentication process from individual applications. PAM consists of a set of dynamically loadable library modules that configures how an application verifies its users before allowing access.

PATH

A shell variable that specifies the directories (and in what order) the shell automatically searches for input commands and files.

PGP (Pretty Good Privacy)

A technique for encrypting messages, often used for e-mail. It includes a secure private- and public-key system similar to RSA. The Linux version of PGP is known as GPG.

physical extent (PE)

A chunk of disk space created from a PV for LVM.

physical volume (PV)

An area of space for an LVM, which usually corresponds to a partition or a hard drive.

Primary Domain Controller (PDC)

A PDC is the governing server on a Microsoft Windows NT 4 network. You can configure RHEL 3 with Samba to function as a PDC.

/proc

/proc is the Linux virtual filesystem. Virtual means that it doesn't occupy real disk space. /proc files are used to provide information on kernel configuration and device status.

public/private key

Encryption standards such as PGP, GPG, or RSA are based on public/private key pairs. The private key is kept on the local computer; others can decrypt it with the public key.

pvcreate

The pvcreate command allows you to configure PEs from a properly configured partition.

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