week 9 lecture Flashcards
what is a system backup?
-Copies files and directories to an archive
-Use to restore data in case of a system failure or data loss and corruption
what is an archive?
File containing many other files, each of which is still identified by its filename, owner, permissions, and timestamp
what is the most common backup medium
tape
what is the tar utility
Tar (tape archive) utility
Archives Files
Extracts Files
what is a full backup?
Archive of all files on the file system
what is an incremental backup?
Archive containing only files modified since the last backup
what is the cpio utility?
Cpio (copy in/out) utility
-Uses the results of the ls or find command to generate files to be archived
what is copy-in mode?
Extract an archive
Use standard input redirection symbol (<) to extract the archive members
what is copy- pass mode?
Copy files and directories from one directory and paste them in another directory
what is compression
Reduces the size of data to store information in less space
what is a compression ratio?
Defines by how much a file is reduced after compressing it
what is the cat command?
Displays an entire file’s contents at once
what is the tic comand?
Display a text file’s contents in reverse order
what is the head command?
Displays the first 10 lines of a text file
what is the tail command?
Displays the last 10 lines of a text file
