MODULE 9- Archiving and compression Flashcards
What term describes combining multiple files into one to reduce overhead and make them easier to transmit?
Archiving
Which type of compression is required for things that must remain intact, like documents, logs, and software?
Lossless compression
What is the term for decompressing an archive and extracting files from it?
Un-archiving
Which type of compression ensures the decompressed file is identical to the original?
Lossless compression
What process removes redundant information from files to reduce storage or transmission size?
Compression
Which type of compression removes information to reduce size, resulting in a file that may be slightly different from the original?
Lossy compression
Which command decompresses files that were compressed with gzip?
gunzip
What kind of files typically use lossy compression to reduce size while maintaining acceptable quality?
Media files like images, audio, and video
What happens when you repeatedly compress and decompress a file using a lossy algorithm?
The file becomes increasingly distorted and may become unrecognizable.
Why is compressing files before sending them to tape or over slow networks often preferred?
It reduces transmission time and improves performance.
Which Linux tool is commonly used to compress files using the Lempel-Ziv algorithm?
gzip
What file extension is added to a file compressed with gzip?
.gz
What command can also be used instead of gunzip to decompress a .gz file?
gzip -d
What is the result of running gzip longfile.txt on a file in Linux?
The file is replaced with longfile.txt.gz, and the original is removed.
What command shows the compression ratio and file sizes of a .gz file?
gzip -l filename.gz
Which compression tool uses the Burrows-Wheeler block sorting algorithm and produces .bz2 files?
bzip2
What is the advantage of bzip2 over gzip?
Better compression ratio, but uses more CPU time.
Which tool is used to decompress .bz2 files in Linux?
bunzip2
What is a key reason to use archiving when backing up directories?
It is easier to manage one archive file than updating many individual files.
Which image format uses lossy compression and allows adjustable quality settings?
JPEG
What compression tool uses the Lempel-Ziv-Markov chain algorithm and produces .xz files?
xz
Which compression tool offers the best of both worlds: gzip-like speed and bzip2-like compression?
xz
Which decompression tool corresponds to the .xz format?
unxz
What is a common misconception when trying to compress an already compressed file?
That it will become smaller, when in fact it usually won’t.
