REISUB feature, 210 – 211
relational databases
explained, 514 – 516
flat files versus, 512 – 513
relaying mail, 595 – 596
release command, 664
release-build command, 665
remote system access
login/logout, 127 – 128
resources for information, 399
SSH (Secure Shell)
installing, 393
key-based logins, 395 – 397
scp command, 394 – 395
sftp command, 395
tools, 393 – 394
Telnet
installing, 391 – 393
SSH versus, 393
VNC (Virtual Network Computing), 397 – 399
removable storage media for backups, 328 – 329
removing
database users (PostgreSQL), 528
directories, 148 – 149 , 179
files, 148 – 149 , 179
jobs, 245
snaps, 122
software. See software management
user accounts, 155