Gfilui

My Ubuntu 16.04 has libsnappy.so.* files in /usr/lib/i386... folders.

• Do I need them?

Also, there is a /usr/lib/snapd.glib folder even after I removed snap.

• Can I just purge all remnants of snap, snapd and snappy related files with brute force?




• Is there a way to remove them intelligently without leaving residues?

I already did apt autoremove and apt autoclean yet these are still here.

These libraries (libsnappy.so.*) are contained in the following packages:

$ dpkg -S libsnappy.so
libsnappy1v5:amd64: /usr/lib/x86_64-linux-gnu/libsnappy.so.1.3.0
libsnappy1v5:amd64: /usr/lib/x86_64-linux-gnu/libsnappy.so.1

$ apt-file search libsnappy.so
libsnappy-dev: /usr/lib/x86_64-linux-gnu/libsnappy.so
libsnappy1v5: /usr/lib/x86_64-linux-gnu/libsnappy.so.1
libsnappy1v5: /usr/lib/x86_64-linux-gnu/libsnappy.so.1.3.0

According to dependencies they are needed on my Ubuntu 16.04 LTS system because of the following reverse dependencies:

$ apt-cache rdepends libsnappy1v5
libsnappy1v5
Reverse Depends:
 libsnappy-dev
 libavcodec-ffmpeg56
 libavcodec-ffmpeg-extra56
 juju-mongodb3.2
 ceph-test
 ceph
 python3-tables-lib
 python3-tables-dbg
 python-tables-lib
 python-tables-dbg
 python-snappy
 mongodb-server
 mongodb-clients
 libwiredtiger0
 libsnappy-jni
 libshogun16
 librocksdb4.1
 libmtbl0
 libblosc1
 libavcodec-ffmpeg56
 libavcodec-ffmpeg-extra56
 juju-mongodb3.2
 juju-mongodb2.6
 juju-mongodb
 ceph-test
 boomaga
 apitrace-gui
 apitrace
 androguard
 ceph
 libleveldb1v5

They are used by the following installed packages:

$ apt-cache rdepends --installed libsnappy1v5 
libsnappy1v5
Reverse Depends:
 libavcodec-ffmpeg-extra56
 python3-tables-lib
 python-tables-lib
 libavcodec-ffmpeg-extra56

So on my system I can't remove libsnappy1v5 package.

snapd and snappy are two different things.

snappy is compression used by hadoop

Wikipedia Snappy compression

Snappy (previously known as Zippy) is a fast data compression and
decompression library written in C++ by Google based on ideas from
LZ77 and open-sourced in 2011.2 It does not aim for maximum
compression, or compatibility with any other compression library;
instead, it aims for very high speeds and reasonable compression.
Compression speed is 250 MB/s and decompression speed is 500 MB/s
using a single core of a Core i7[which?] processor running in 64-bit
mode. The compression ratio is 20–100% lower than gzip.

snapd - what is snap

• is a squashFS filesystem containing your app code and a snap.yaml file containing specific metadata. It has a read-only file-system and,
  once installed, a writable area.




• is self-contained. It bundles most of the libraries and runtimes it needs and can be updated and reverted without affecting the rest of
  the system.




• is confined from the OS and other apps through security mechanisms, but can exchange content and functions with other snaps according to
  fine-grained policies controlled by the user and the OS defaults.