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Category: User accounts

adjusting screen lock duration

Published by jweisber on 2022-01-02

in very top right of screen, on banner is an icon that is a circle, broken on top with a dot in middle of break.  hit it!  >>Joel Weisberg (or your name here)>>Account Settings.
Look on far left of resulting popup at the “Details” column which has a left arrow next to it.
Hit the left arrow to open up the “settings” column and scroll ‘way down to, and select “privacy.”
Then hit <cntrl>screenlock and you can select from a menu of “lock screen after blank for
<? minutes>.

–Joel. (Yes what a pain! This was really hard to figure out because it is so buried.)

setting up your centos7 desktop after machine was upgraded to that os

Published by jweisber on 2021-03-04

These notes are mostly from Bruce. The original is at /docs/centos7/

Centos 7 Gnome UI configuration
====================================================================================================

CentOS 7 comes with some UI changes from the centos6 experience that you may wish to adjust.

See below for concrete examples below for commonly changed settings.

Generally speaking, there are 4(!) tools that allow you to adjust aspects of your UI environment. 3
via the System Menu (Upper Left corner of your screen) and 1 via the ‘gsettings’ shell CLI.

Determing which of these 4 tools provides the setting you want to change can be challenging. It’s
often easiest just to google for “centos 7 change <???> settings” to find out which one[s] to use
for the given setting you want to change.

The 4 ways to change the UI:

1) “Applications > Tweaks > XXX”

This brings up the ‘Gnome Tweak Tool’ that lets you set a bunch of things.

Example:

Applications > Tweaks > Keyboard & Mouse >

let’s you map the Caps Lock key to an additional Ctrl key (see below)

2) “Applications > System Tools > Settings > XXX”

Example:

Applications > System Tools > Settings > Privacy > Screen Lock

3) “Applications > System Tools > dconf Editor”

This is a bare-bones editor that enables you to get/set the same tree of settings that can be
manipulated by the ‘gsettings’ CLI below, which is a superset of what can be changed via the
Gnome Tweak Tool above.

org/gnome/desktop/screensaver/lock-delay
org/gnome/desktop/interface/text-scaling-factor

4) The ‘gsettings’ Shell (Terminal Window) command:

This is the shell get/set CLI for the dconf Editor above

Examples:

$ gsettings get org.gnome.desktop.screensaver lock-delay
uint32 300
$ gsettings set org.gnome.desktop.screensaver lock-delay 600
$ gsettings get org.gnome.desktop.screensaver lock-delay
uint32 600
$

Sources:

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/desktop_migration_and_administration_guide/gsettings-dconf

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/desktop_migration_and_administration_guide/browsing-gsettings-values-for-applications

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/desktop_migration_and_administration_guide/configuration-overview-gsettings-dconf

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/desktop_migration_and_administration_guide/browsing-gsettings-values-for-applications

 

====================================================================================================
Specific examples
====================================================================================================

—————————————————————————————————-
Put App shortcuts on the desktop
—————————————————————————————————-

You can click-and-drag any of the app icons from any submenu of the main ‘Applications’ menu to the
desktop and then launch it from there.

—————————————————————————————————-
Put App shortcuts on the ‘top panel’
—————————————————————————————————-

I haven’t found a way to do this yet.

—————————————————————————————————-
Shrink Desktop Icon size
—————————————————————————————————-

Desktop Icons are stupidly large. Fix with

# gsettings set org.gnome.nautilus.icon-view default-zoom-level small

—————————————————————————————————-
Font sizes used on the screen are oversized
—————————————————————————————————-

Make fonts smaller via

Applications>Accessories>Tweaks>Fonts>Scaling Factor -> 0.90

—————————————————————————————————-
Make menu clock show the Date and Seconds
—————————————————————————————————-

Applications > Tweaks > Top Bar

Under ‘Clock’ header

Controls how clock appears in screen’s top menu bar

Date [on|off]
Seconds [on|off]

—————————————————————————————————-
Configure Startup Applications
—————————————————————————————————-

You can specify what applications you want to have launched at login.

Applications > Tweaks > Startup Applications

Select the apps you want to run at startup.

—————————————————————————————————-
Make ‘Caps Lock’ key an additional ‘Ctrl’ key
—————————————————————————————————-

Very useful for emacs users.

NOTE: Make sure Caps Lock is not active when you do this!

Applications > Tweaks > Keyboard & Mouse >

Under ‘Keyboard’ heading, select the ‘Additional Layout Options’ button.

In the ‘Additional Layout Options’ window that pops up, select the ‘Caps Lock Behavior’ ‘triangle’
button and then select ‘Caps Lock is also a Ctrl’.

—————————————————————————————————-
Adjust the screensaver lock timer
—————————————————————————————————-

The screensaver lock timer is very aggressive. To adjust, open “Applications > System Tools >
Settings > Privacy > Screen Lock”

In the ‘Screen Lock’ window you can select the ‘Lock screen after blank for’ value from ‘Screen
Turns Off’ to a number of minutes, such as 1, 2, 5, or 30 minutes (but not anything between 5 and 30
minutes which is odd).

If you want to set the timer to values between 5 <-> 30 minutes, you can use the ‘gsettings’ CLI.

Here’s how to do it via ‘gsettings’:

From the terminal (to set sleep timeout to 10 minutes / 600 seconds,
then require login after 15 minutes / 900 seconds):

gsettings set org.gnome.settings-daemon.plugins.power sleep-display-ac 600
gsettings set org.gnome.settings-daemon.plugins.power sleep-display-battery 600
gsettings set org.gnome.desktop.session idle-delay 600
gsettings set org.gnome.desktop.screensaver idle-activation-enabled ‘true’
gsettings set org.gnome.desktop.screensaver lock-enabled ‘true’
gsettings set org.gnome.desktop.screensaver lock-delay 900

—————————————————————————————————-
Set prefs for Nautilus (File Manager)
—————————————————————————————————-

Open ‘Applications > File Manager’ from the menu in the Upper Left of your screen.

The Nautilus File Manager should open.

In the top menu bar you should now see the ‘Files’ menu item

From the ‘Files’ menu, select ‘Preferences’

—————————————————————————————————-
Set prefs for Konqueror (File Manager): Joel notes that konqueror file manager is back, after being missing from centos6.  I like konqueror much more than nautilus (it shows link targets, a particular issue of mine.)  So I set it up on centos7.  Rather than telling you all the miriad of settings I needed to select and change, how about you just ask me to tell you all the settings if you are interested (ie if you are frustrated with nautilus)
—————————————————————————————————-
—————————————————————————————————-
Update Firefox UI “Experience”
—————————————————————————————————-

When you launch Firefox it will ask you if you want to update your ‘experience’. Say ‘yes’ and it
will relaunch but show the latest UI.

—————————————————————————————————-
Configure the GV.printCommand:
—————————————————————————————————-

GV’S print command dialog window has a type-in labeled ‘print command’ and it’s automagically
populated with the string ‘lpr’. However you can change that string to ‘ps2pdf %s – | lpr’. You
can also change the default print string from ‘lpr’ to whatever you want in GhostScript options, but
that would break printing of non .ps files.

To change the default print string in ‘gv’, select:

State->Setup Options

… Look for the Print Command field, and change the value from
‘lpr’ to ‘ps2pdf %s – | lpr’ (w/o the single quotes).

The change is saved to ~/.gv as the line:

GV.printCommand: ps2pdf %s – | lpr

Ssh security

Published by jweisber on 2021-03-04

Directions from Bruce. (BDUFFY 2021-02-17. )Thanks Bruce! Slightly updated by Joel. These were specifically for setting up to ssh to new mirzam, but are relevant for any new host.

Remove old mirzam entries from your ~/.ssh/known_hosts file  (It looks like very long lines of gibberish. A hostname or its internet number [ie 137.22.301.5] starts each line.)

The next time you ssh into to an astronet machine, ssh will ask you

(base) bduffy66924:~ bduffy$ ssh bduffy@mirzam.physics.carleton.edu
The authenticity of host ‘mirzam.physics.carleton.edu (137.22.6.129)’ can’t be established.
ECDSA key fingerprint is SHA256:nersU93cf8F5ucysog/Rn2OIbSabknw10hpw5uXFs3o.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added ‘mirzam.physics.carleton.edu’ (ECDSA) to the list of known hosts.
bduffy@mirzam.physics.carleton.edu: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
(base) bduffy66924:~ bduffy$

See ./astronet-server-ssh-public-keys.txt

2021 05 17:  JMW does not know what directory ^ this is in.

Also, I had to add the authorized_keys file to one of my home macs’ .ssh directory in order to get all the way in to canopus.  See email from Bruce on 2021 05 17 for more details.

clear firefox cache cleanly to free up space and not overflow quota

Published by jweisber on 2020-05-26

A cleaner way to free up firefox cache space, was provided by Mike Tie via Bruce Duffy.

I noticed I couldnt log in to carleton email via astronet firefox and these guys said it was because of a carcass in cache. So this is the procedure for clearing cache, which can also often bring a user’s space down below their quota limit:

Firefox has cached the old info, and now you need to clear the firefox cache. To do that, Launch firefox, click the three bars in the upper right corner of the firefox window, click Preferences, click the lock icon (middle left of the window), scroll down to “Coookies and Site Data”, click on “Clear Data…”, make sure both items are checked, and click “Clear”, and then click “Clear Now”.

To access weekly online backup on canopus last updated 2024 August

Published by jweisber on 2012-12-04

Newest update 2024 Aug to reflect that backups are have been stored on canopus: for several years:

Go to canopus:/thuban2-backups

Bruce has an automatic (cron) job do a weekly backup of thuban onto canopus.

On canopus,

df -h gives the various mount points, incl
“Filesustem” /dev/mapper/centos_canopis-thuban2–backups”\
” Mounted on”  /thuban2/backups

Navigate down to whatever file you’re looknig for, and copy over to a safe place (Careful: do not overwrite newer file of same name on thuban!)

See also post on root superuser privileges on thuban2  (although current post you are reading deals with canopus, which is where weekly backups are stored).

–joel

Quota Check

Published by jweisber on 2010-01-22

Added a script to the bashrc, zshrc, and csh.cshrc files that automatically checks if you are over your quota.

Every time you open a new terminal, run an xterm, or ssh into a computer it should echo “Quotacheck OK (/home/$USER is <used/softcap>% full)” if you are under quota. If you are over quota it will tell you, so either delete files or talk to Joel about increasing your quota size.

How fix “Firefox already in use” problem

Published by jweisber on 2009-07-23

Our shared home directories sometimes confuse Firefox, causing it to fail to launch while posting a dialog window saying that “Firefox is already in use”.

The only solution I’ve found that really works is somewhat drastic. It requires you to delete your ~/.mozilla/firefox directory, which has the effect of deleting your bookmarks.

To preserve your bookmarks, we must first export them to a temporary location, exit Firefox, delete your ~/.mozilla/firefox directory, relaunch Firefox, and then import your bookmarks from the temporary location.

Here’s the step by step solution:

1. To get Firefox to launch (in a somewhat hosed state) so that you can save your bookmarks, open a terminal window and issue these commands:

rm -f ~/.mozilla/firefox/*.default/lock
rm -f ~/.mozilla/firefox/*.default/.parentlock

2. Launch Firefox. It will be somewhat hosed, but you should be able to export your bookmarks by opening the Bookmarks window by selecting “Bookmarks->Organize Bookmarks” from the Browsers menu. Once the Bookmarks window appears, click on the “Import and Backup” menu and select “Backup”. A “Bookmarks backup” window will pop up prompting you for a location to save your bookmarks to. Just go with the default values, which should save a “Bookmarks <date>.json” file to your Desktop.

3. Exit Firefox

4. From a terminal window, issue this command:

rm -f ~/.mozilla/firefox/

5. Launch Firefox. At this point Firefox should behave normally and you can restore your bookmarks by opening the Bookmarks window and selecting “Bookmarks->Organize Bookmarks” from the Browsers menu. Once the Bookmarks window appears launched, click on the “Import and Backup” menu and select “Restore”. A dropdown list of of bookmark backup files should pop up, and you can select the most recent one to restore your bookmarks.

Bumped user quotas due to Firefox disk usage

Published by jweisber on 2009-06-01

The /home user quotas for all existing users has been bumped from 80M to 200M to handle Firefox’s big disk footprint.

Our former quota of 80M was insufficient for the latest version of Firefox. By default Firefox uses 50M for file caching and another 30M->90M to stash a per-user copy of an anti-phishing blacklist file. Together, these two things could consume the entire original quota of 80M through normal Firefox usage. Rather than turning off Firefox’s cacheing and anti-phishing features I asked James to bump the quota from 80M to 200M and edited the ‘new user’ checklist post with the new values.

Change users quota (MUST BE *THUBAN* ROOT)

Published by jweisber on 2008-07-09

type edquota <username> as root on thuban.

this drops you into a vi editing session.

change the quota as desired and then exit the session.

If you are not familiar with vi, you may find more details on how to edit this file under the “new user” post, where the setting up of a quota for a new user is discussed.

–Joel

sudoer list

Published by admin-joel on 2007-07-17

As of this post date 2007, the Astro network syncs thuban’s sudoers file to the other workstations, just as it does with user accounts. Please contact fullerj with any problems regarding sudo.