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Workshop » Reference Section » Grimoires » IT » Platforms » Linux » Packages » rsync & rsnapshot

Reducing rsnapshot or rsync resource usage

I've had sporadic problems with clearing the WP cache causing the server to return 520 errors for a few minutes. Usually other sites on the same server are fine, it's specific to this vhost. Logging in via SSH, checking with htop, rsync is usually hogging most of the cpu. Restarting the fpm and then restarting Apache restores the website.

According to https://www.claudiokuenzler.com/blog/361/rsnapshot-backup-reduce-high-load-with-ionice, the big bottleneck with rsync, which rsnaphot runs on, is i/o, not cpu, and rsync can actually tie up i/o such that a web server won't respond to http requests. This can be solved by making the rsnapshot command in crontab ionice -c 3 [rsnapshot command] instead of just the rsnapshot command, which tells rsync not to wait until the disk is idle before trying to access it. So I did. In fact, I made it nice -n 19 ionice -c 3 [rsnapshot command] although…

Workshop » Reference Section » Grimoires » IT » Platforms » Linux » Packages » Git

Force Git to overwrite local changes if there is a branch conflict

Use code you find here at your own risk! I am not responsible if you damage your data or system by following any instructions you find here.

  1. Navigate to your plugin's root directory:

    Bash

    cd /home/kupietzc/public_html/kartscode/wp-content/plugins/ktwp-draggable-elements

  2. Fetch the latest changes from GitHub:
    Bash

    git fetch origin

  3. Perform a hard reset to match GitHub's main branch (assuming main is your branch):

    Bash
    git reset --hard origin/main

    WARNING: This command is destructive. It will discard all local changes to tracked files and make your local repository exactly match your GitHub repository. Ensure you have a backup of any local modifications you wish to preserve that are NOT on GitHub before running this.

  4. Clean up any untracked files or directories (remnants from manual copying):
Workshop » Reference Section » Grimoires » IT » Applications » Web Browsers » CSS

Getting Web Browsers Not To Blur Images on Retina Screens

Unfortunately this must be set by site, but on retina screens on MacOS, many browsers blur small images, such as 88x31 buttons.

You can overcome this, at least for the images on your site, by adding this CSS to your site:

img, div {
image-rendering: optimizeSpeed;
image-rendering: -moz-crisp-edges;
image-rendering: -webkit-optimize-contrast;
image-rendering: optimize-contrast;
image-rendering: pixelated;
-ms-interpolation-mode: nearest-neighbor;
}

You should add any element that might have a CSS background image property to that selector. In this case I have added

because I have many divs with background images on this site.

This tip is from https://stackoverflow.com/questions/31908444/fix-for-blurry-images-on-browsers-used-by-a-mac-retina

Workshop » Reference Section » Grimoires » IT » Platforms » MacOS » Apps

How to fix if the “Save” button is grayed out in Photoshop CC 2017 save and export dialogs

I don't know if this affects other versions of Photoshop, but on MacOS Photoshop CC 2017 frequently starts unexpectedly graying out all save buttons when you have made changes to your file and should be able to save.

The secret is to resize and move around the dialog. Drag the lower right corner to make it bigger and smaller a few times, and try dragging the whole dialog to the upper left corner of the screen and making it small.

This fixes it for me.

Workshop » Reference Section » Grimoires » IT » Applications » Web Browsers » Addons

Filtering LinkedIn Posts, Notifications, and Comments by keyword

I use the uBlock Origin browser plugin to filter my LinkedIn Posts, Notifications, and Comments to hide anything containing objectionable topics. uBlock Origin allows you to add custom rules to block web content.

How to use and setup uBlock Origin is beyond the scope of this post. It's not hard, figure it out and then come back. What you want to know how to do is add your own custom rules.

Let's say, for purposes of these example, I want to block all mentions of someone named Grump.

The simplest version: block a single word

The following three rules hide Posts, Comments, and Notifications, respectively, that contain the word "grump", whether as a separate word, or as part of other words, such as "grumpier".

Posts: www.linkedin.com##div:has( > .ember-view.occludable-update:has(div.fie-impression-container:has-text(/grump/i)))
Comments: www.linkedin.com##.comments-replies-list > .comments-thread-entity > .comments-thread-item > .comments-comment-entity--reply.comments-comment-entity:has-text(/grump/i)
Notifications: www.linkedin.com##div[data-finite-scroll-hotkey-item]:has-text(/grump/i)

That's the basics. But…

Workshop » Reference Section » Grimoires » IT » Troubleshooting log » WordPress

Deactivating, deleting, and completely removing a plugin that WordPress won’t let you deactivate

I installed the WordPress plugin LWS Optimize, which turned out to be unusably broken (which is the reason I'm not linking to it) and made my site unusable. To make matters worse, when I tried to deactivate it, it told me it deactivated... and was still active. I went in through FTP and deleted the plugin folder entirely, and then WordPress said it had been deactivated because it couldn't be found... and it still showed as present and activated in the plugin list.

So I added this to my theme's functions.php file:

add_action('admin_init', function() {
$active_plugins = get_option('active_plugins');
$plugin_to_remove = 'lws-optimize/lws-optimize.php';

if (($key = array_search($plugin_to_remove, $active_plugins)) !== false) {
unset($active_plugins[$key]);
update_option('active_plugins', array_values($active_plugins));
}
});

I then reloaded an admin page and removed that. That deactivated the plugin in the plugins list, but then when I hit the "delete" link, it said it…

Workshop » Reference Section » Grimoires » IT » Troubleshooting log

Website returns 503 server errors, but no errors in logs

Had a weird one today. Last one website of the several of on this server suddenly started returning 503 (service unavailable) errors. There was nothing in the PHP error log or Apache error log. All server configs are already thoroughly optimized for performance. Other websites on the same server were functioning normally.

I didn't notice this at the time, but my uptime monitor didn't report an outage. When I used redirect-checker.com to check the status code, it returned 200, which should have been a clue, also.

Next time, before doing all sorts of arcane troubleshooting:
1. Try with a different browser
2. Is there a CDN? Try bypassing it.
3. Are you using a VPN? Try selecting a different endpoint (VPN server) if it will let you, or turning it off.

I use the NordVPN plugin in Firefox, and quic.cloud is my…

Workshop » Reference Section » Grimoires » IT » Applications » FileMaker Pro

Get names of all input fields in a FileMaker Pro table

ExecuteSQL ( "SELECT FieldName FROM FileMaker_Fields WHERE TableName='[TABLE NAME]' AND FieldClass='Normal'",",","¶")

Workshop » Reference Section » Grimoires » IT » Platforms » Linux » Packages » PHP

How to monitor RAM for tuning pm.max_children

How to monitor RAM usage:

  1. free -h:

    • This command shows your system's total, used, and free memory in a human-readable format.
    • Key metrics:
      • total: Total RAM.
      • used: RAM currently in use.
      • free: Unused RAM.
      • buff/cache: RAM used for file system buffers and page cache. This is good; Linux uses free RAM for this and frees it when applications need it.
      • available: The most important metric. This estimates how much memory is available for starting new applications without swapping.
    • Run it before and after: Run free -h before you increase max_children and then after your server has been running for a while under typical load with the new settings. Compare the available memory.
  2. htop (recommended if installed):

    • htop (you might need to sudo…
Workshop » Reference Section » Grimoires » IT » Platforms » Linux » Packages » cron

Add sar logging for CPU, RAM, and disk I/O

Add or change /etc/cron.d/sysstat to this. This creates a cron jobe to write file /tmp/outage_resource_log.txt that keeps minute-by-minute stats, sometimes useful in troubleshooting slowdowns. However, it's not a great way to do things, it create a small, constant resource drag, so disable it when done troubleshooting.

# The first element of the path is a directory where the debian-sa1
# script is located
PATH=/usr/lib/sysstat:/usr/sbin:/usr/sbin:/usr/bin:/sbin:/bin

# Activity reports every 10 minutes everyday
#ORIGINAL DEFAULT WAS 5-55/10 * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1
#uncomment above line and comment out /tmp/outage_resource_log.txt lines to restore original functionality
* * * * * root date +"%Y-%m-%d %H:%M:%S" >> /tmp/outage_resource_log.txt
* * * * * root sar -u 1 1 >> /tmp/outage_resource_log.txt 2>&1
* * * * * root sar -r 1 1 >> /tmp/outage_resource_log.txt 2>&1
* * *…

Workshop » Reference Section » Grimoires » IT » Platforms » Linux » Packages » Apache

Add /fpm-status page to Apache virtual host

Add this to virtual host file in /etc/apache2/sites-available/, right below DocumentRoot, in both :80 and :443 sections



SetHandler "proxy:unix:/var/php-fpm/170027027353667.sock|fcgi://127.0.0.1"
Require all granted

May need in /etc/php/8.2/fpm/pool.d/www.conf, not sure:
pm.status_path = /fpm-status

May need at very start of .htaccess to prevent wordpress from intercepting the URL, not sure:
RewriteRule ^fpm-status$ - [L]

Workshop » Reference Section » Grimoires » IT » Platforms » Linux » Packages » Apache

View last 200 lines of all access logs on apache server

find [path/to/access/logs/folder] -name "*_access_log" -exec sh -c 'tail -200 "$1" | grep -v "HetrixTools\|ok\.txt\|canary" | sed "s/$/ [$(basename "$1" _access_log)]/"' _ {} \; | sort -k4,4

The grep -v "HetrixTools\|ok\.txt\|canary" filters out hits from my uptime monitor.

Workshop » Reference Section » Grimoires » IT » Platforms » Linux » Packages » fail2ban

How to check Fail2ban log

Command to check fail2ban's log is sudo tail -f /var/log/fail2ban.log

Linux

Linux PHP tuning utilities & commands

1. See memory consumed by php-fpm8.2 (change this to match different PHP version if necessary)

ps --no-headers -o "rss,cmd" -C php-fpm8.2 | awk '{ sum+=$1 } END { printf ("%d%s\n", sum/NR/1024,"M") }'

Linux

Linux SQL Tuning Utilities

1. tuning-primer.sh

Run from Github:
curl -L https://raw.githubusercontent.com/BMDan/tuning-primer.sh/main/tuning-primer.sh | bash

2. MySQLTuner.pl

wget http://mysqltuner.pl/ -O mysqltuner.pl
wget https://raw.githubusercontent.com/major/MySQLTuner-perl/master/basic_passwords.txt -O basic_passwords.txt
wget https://raw.githubusercontent.com/major/MySQLTuner-perl/master/vulnerabilities.csv -O vulnerabilities.csv
perl mysqltuner.pl --host 127.0.0.1 --user [user] --pass [pass]

Remember to quote any punctuation or BASH tokens in the password.

Workshop » Reference Section » Grimoires » IT » Troubleshooting log

/Devlog

  • 2026apr17
    • Change all em on hero css to rem
    • .hover-slide-item:hover > .slide-inner > .cat-links > .mmarker-child-a { font-size: 1em; ... to 1rem
  • 2026apr16
    • .mmarker-child-a, .meta-genre-or-workinprogress { ... font-size: 1em;...} to 1rem
    • Add clamped vw-based font size on :root for large displays, and .hero_h3 { font-size: 1.65em;... to 1.65rem
    • Update HTMLmap so sitemap has Details elements to collapse sections.
  • 2026apr15
    • update entry-summary template with force_balance_tags to fix excerpts ending in the middle of tag innertext
  • 2026apr14
    • Added .article-horizontal-archive > div.si-blog-entry-wrapper > .entry-media > a > img rule for thumbnails on othercatposts blogformat lists
    • add .wide class to in othercatbposts when blogformat is used
    • add .article-horiontal-archive to horizontal template so can apply CSS when used in othercatposts, not just on archive page
    • Change overflow-x to hidden on details previews so shows ellipsis on mobile
  • 2026apr6
    • Updated "AI copyright"…