Ubuntu 17.04 Now Available For Download

[Nth_man]

Swap keeps being used nowadays when "large programs make the entire system need extra memory. A significant number of the pages used by these large programs during its startup may only be used for initialization and then never used again. The system can swap out those pages and free the memory for other programs or even for the disk cache. In these cases, swap will be used to help the system handle any extra load.", etc.

[devius]

It was written in <https://help.ubuntu.com/community/SwapFaq>:
...
Sometimes, a large program (like LibreOffice, Neverwinter Nights, or a video editor)...

That's my kind of answer

Now seriously, this was probably written sometime between 2002-2004, so not sure if it's still relevant today.

[uid313]

Too bad old version of PHP, Python and Wine.
Many GNOME packages are also outdated.

You might want to have a script to configure your system to your liking if you do a reinstall or get a new system. It might look something like this.

# Enable the firewall
sudo ufw enable
sudo ufw logging off

# Get some codecs to play media
sudo apt-get install gstreamer1.0-plugins-ugly gstreamer1.0-libav

# Add third-party PPA repositories
sudo add-apt-repository ppa:ubuntu-wine/ppa

# Get some software I like
sudo apt-get install synaptic gnome-session-flashback blender chromium-browser hexchat pepperflashplugin-nonfree gimp lm-sensors p7zip redshift stjerm vlc wine2.0

# Pepper Flash for Chromium
sudo /usr/sbin/update-pepperflashplugin-nonfree --install

# Setup web server
sudo apt-get install lighttpd php-cgi php-sqlite
sudo lighty-enable-mod fastcgi
sudo lighty-enable-mod fastcgi-php
sudo phpenmod pdo_sqlite pdo_mysql

# Fetch some stuff
wget https://fpdownload.adobe.com/get/flashplayer/pdc/25.0.0.148/flash_player_npapi_linux.x86_64.tar.gz
wget https://github.com/shimmerproject/Greybird/tarball/master -O greybird.tar.gz
wget https://github.com/shimmerproject/Numix/tarball/master -O numix.tar.gz
wget https://fc00.deviantart.net/fs71/f/2011/332/3/b/derp_by_lassekongo83-d4hklmr.7z
wget https://github.com/lassekongo83/zuki-themes/tarball/master -O zuki-themes.tar.gz

# Configure themes (in /usr/share/themes/ or ~/.themes/)
gsettings set org.gnome.metacity theme Greybird

# Ignore GNOME HIG, we want a classic black terminal
#gconftool-2 --set --type bool /apps/gnome-terminal/profiles/Default/use_theme_colors false
#gconftool-2 --set --type string /apps/gnome-terminal/profiles/Default/background_color '#000000000000'
#gconftool-2 --set --type string /apps/gnome-terminal/profiles/Default/foreground_color '#FFFFFFFFFFFF'
#gconftool-2 --set --type string /apps/gnome-terminal/profiles/Default/background_type 'transparent'
#gconftool-2 --set --type float /apps/gnome-terminal/profiles/Default/background_darkness '0.75'

# Hide the keyboard layout indicator applet
gsettings set com.canonical.indicator.keyboard visible false
# Hide name from me-menu, hide input menu from context menu
gsettings set com.canonical.indicator.session show-real-name-on-panel false
gsettings set org.gnome.desktop.interface show-input-method-menu false
gsettings set org.gnome.desktop.interface show-unicode-menu false

# Hide text labels from toolbar
gsettings set org.gnome.desktop.interface toolbar-style 'icons'

# Dont show apps in the repository when searching in Unity dash
gsettings set com.canonical.Unity.ApplicationsLens display-available-apps false
# Disable remote searches (Amazon, Facebook, Twitter, BBC, etc) from Unity dash
gsettings set com.canonical.Unity.Lenses remote-content-search 'none'
# Disable Unity spam scopes
gsettings set com.canonical.Unity.Lenses disabled-scopes "['more_suggestions-amazon.scope', 'more_suggestions-u1ms.scope', 'more_suggestions-populartracks.scope', 'music-musicstore.scope', 'more_suggestions-ebay.scope', 'more_suggestions-ubuntushop.scope', 'more_suggestions-skimlinks.scope']"

# 10 minutes instead of 5 minutes
gsettings set org.gnome.desktop.session idle-delay 600

# I need Alt+click for apps and games, so lets use WinKey instead
gsettings set org.gnome.desktop.wm.preferences mouse-button-modifier '<Super>'

# Use WinKey instead of Alt for the window management hotkeys (Metacity)
gsettings set org.gnome.desktop.wm.keybindings begin-move "['<Super>F7']"
gsettings set org.gnome.desktop.wm.keybindings begin-resize "['<Super>F8']"

# Use WinKey instead of Alt for the window management hotkeys (Compiz)
gconftool-2 --set --type string /apps/compiz-1/plugins/move/screen0/options/initiate_key '<Super>F7'
gconftool-2 --set --type string /apps/compiz-1/plugins/resize/screen0/options/initiate_key '<Super>F8'

# Other Compiz settings
gconftool-2 --set --type bool /apps/compiz-1/plugins/cube/screen0/options/skydome true
gconftool-2 --set --type bool /apps/compiz-1/plugins/cube/screen0/options/skydome_animated true

# I want my window management buttons on the right side
gsettings set org.gnome.desktop.wm.preferences button-layout 'menu:minimize,maximize,close'

# Get minimize and maximize button back on the gnome-shell titlebar
gsettings set org.gnome.shell.overrides button-layout 'menu:minimize,maximize,close'

# Settings for the civilized world
gconftool-2 --set --type string /apps/panel3-applets/clock/format '24-hour'
gconftool-2 --set --type string /apps/panel3-applets/clock/speed_unit 'm/s'
gconftool-2 --set --type string /apps/panel3-applets/clock/temperature_unit 'C'
gsettings set com.canonical.indicator.datetime time-format '24-hour'
gsettings set org.gnome.GWeather distance-unit 'km'
gsettings set org.gnome.GWeather speed-unit 'ms'
gsettings set org.gnome.GWeather temperature-unit 'centigrade'
#gsettings set org.gnome.desktop.interface clock-format '24h'

# Turn gedit into programming mode
gsettings set org.gnome.gedit.preferences.editor auto-indent true
gsettings set org.gnome.gedit.preferences.editor bracket-matching true
gsettings set org.gnome.gedit.preferences.editor display-line-numbers true
gsettings set org.gnome.gedit.preferences.editor display-right-margin true
gsettings set org.gnome.gedit.preferences.editor highlight-current-line true
gsettings set org.gnome.gedit.preferences.editor scheme 'oblivion'

# File templates
echo '#!/usr/bin/env python' > "$(xdg-user-dir TEMPLATES)/Python.py"
echo '#!/usr/bin/env perl -w' > "$(xdg-user-dir TEMPLATES)/Perl.pl"
echo '<?php' > "$(xdg-user-dir TEMPLATES)/PHP.php"
echo '#!/usr/bin/env ruby' > "$(xdg-user-dir TEMPLATES)/Ruby.rb"
echo '<!DOCTYPE html>' > "$(xdg-user-dir TEMPLATES)/HTML.html"

# Configure Git
git config --global user.email "[email protected]"
git config --global user.name "Your Name"

# Disable third-party non-free software repositories
sudo add-apt-repository -r multiverse
sudo add-apt-repository -r restricted

[Nth_man]

It was written in <https://www.kernel.org/doc/gorman/html/understand/understand014.html>:
There are two principle reasons that the existence of swap space is desirable. First, it expands the amount of memory a process may use. Virtual memory and swap space allows a large process to run even if the process is only partially resident. As “old” pages may be swapped out, the amount of memory addressed may easily exceed RAM as demand paging will ensure the pages are reloaded if necessary.

The casual reader may think that with a sufficient amount of memory, swap is unnecessary but this brings us to the second reason. A significant number of the pages referenced by a process early in its life may only be used for initialisation and then never used again. It is better to swap out those pages and create more disk buffers than leave them resident and unused.

__________________________________________________ ______________________________________________

It was written in <https://help.ubuntu.com/community/SwapFaq>:
Why do I need swap?

Memory consuming programs:
Sometimes, a large program (like LibreOffice, Neverwinter Nights, or a video editor) make the entire system need extra memory. A significant number of the pages used by these large programs during its startup may only be used for initialization and then never used again. The system can swap out those pages and free the memory for other programs or even for the disk cache. In these cases, swap will be used to help the system handle any extra load.

Hibernation (suspend-to-disk):
The hibernation feature (suspend-to-disk) writes out the contents of RAM to the swap partition before turning off the machine. Therefore, your swap partition should be at least as big as your RAM size. The hibernation implementation currently used in Ubuntu, swsusp, needs a swap or suspend partition. It cannot use a swap file on an active file system.

Unforeseeable Circumstances:
Unforeseeable events can and will happen (a program going crazy, some action needing much more space than you thought, or any other unpredictable combination of events). In these cases, swap can give you an extra delay to figure out what happened, or to finish what you are working on.

Optimizing memory usage:
Because mechanical hard drives are considerably slower than RAM (SSD - Solid State Drive - storage is not as slow as physical drives, but still slower than RAM), when you need a file (be it a data file like a video, executables like Firefox, or libraries), the Linux kernel reads the file into RAM and keeps it there, so that the next time you need it, it is already in RAM and data access is much faster. The portions of RAM that accelerate disk read are called "cached memory." You will notice that they make a huge difference in terms of responsiveness. The Linux kernel automatically moves RAM reserved by programs --but not really used-- into swap, so that it can serve the better purpose of extending cached memory.
__________________________________________________ ______________________________________________

Swap is useful as a safety belt:

Swap is useful as a safety belt. When you get an application that starts eating up all your system memory, you'll notice that your machine suddenly became slow, and, hopefully, will be able to kill that app before your swap gets exhausted. Without swap, at this point the machine usually becomes completely nonresponsive, and the kernel's OOM killer doesn't always trigger as soon as you want, and it doesn't always kill the process you want to kill.

__________________________________________________ ______________________________________________

Swap serves another (often underrated) purpose: Graceful degradation.

If you have a reasonably amount of swap space mounted, you will know you are running out of RAM because your system will become noticeably slower. If you have no swap whatsoever [or if it is filled too quickly], your first warning will quite possibly be an application OOM killed or losing data due to a failed memory allocation.

Think of the slowness of swap as a _feature_.

[bug77]

This is what system monitor is telling my about my system's usage:
RAM: 5.7GB used out of 31.4GB
SWAP: 687MB used out of 4GB

So no, if you have a large memory your system may still use the swap. You might wonder why would the system do that and the answer is that it might determine, depending on your usage, that it's more beneficial performance-wise to use the available RAM as file cache rather than as ram for some backgrounded app. In other words, when the available ram is full with cached files and the system need more memory it might decide to swap a backgrounded app rather than reduce file cache size.

Leaving the obvious aside for a minute (of course swap will be used, that's why it's there), are you schooling me about swap while having your 32GB RAM system configured to use 4GB swap?

[hax0r]

Looks like there is some issue with not being able to upgrade to 17.04, the Upgrade prompt isn't appearing and trying to trigger the upgrade manually with 'do-release-upgrade' returns: No new release found

[sarmad]

Not really. The swap partition is a solution for the HDD era. I haven't used a swap partition in years and never noticed a performance difference. Plus, with 8+ GB RAM, Linux hardly swaps anyway.

This is what system monitor is telling my about my system's usage:
RAM: 5.7GB used out of 31.4GB
SWAP: 687MB used out of 4GB

So no, if you have a large memory your system may still use the swap. You might wonder why would the system do that and the answer is that it might determine, depending on your usage, that it's more beneficial performance-wise to use the available RAM as file cache rather than as ram for some backgrounded app. In other words, when the available ram is full with cached files and the system need more memory it might decide to swap a backgrounded app rather than reduce file cache size.

[sarmad]

"Another pleasant change of Ubuntu 17.04 is the move on new installations from using SWAP partitions to just using swap files now, for saving space and being easier to manage. "

Isn't performance much better with swap partitions though? I thought that was the main reason that Linux retained them.

I think performance is better on old disks, but on SSDs there is probably less difference. Also in SSDs it's recommended to have the entire disk as one partition to reduce the wear out on the disk.

[discordian]

Not really. The swap partition is a solution for the HDD era. I haven't used a swap partition in years and never noticed a performance difference. Plus, with 8+ GB RAM, Linux hardly swaps anyway.

If you mount /tmp as tmpfs and use it for builds with some 100000s temporary files instead of perforating a filesystem (and draining writes of the SDD), you will want a safeguard. With swap you can use big tmpfs mount and dont have to fear a small spike will cause havoc.
If you have more RAM than your system needs at anytime (including data thats never used and could be written out once), then you dont need swap. But that was always the case.

BTW, you can set "swappiness" to zero and avoid any eager swaps to disk. The only time the kernel will write to disk will be when the system would`ve run out of RAM without swap (and killed some Processes that may or may not be the ones eating away all RAM).

[Azrael5]

I'm waiting for Lubuntu and Kubuntu.