After updating ImageMagick to version 6.9.10.23+ from an earlier version, the following behavior occur : Thumbnails generation from PDF, XPS, PS, and EPS does not work anymore The following output can be found in the Web server error log : PHP Fatal error: Uncaught ImagickException: attempt to perform an operation not allowed by the security… Read More »
Here is an easy way to output in a single command the Apache memory usage and average process size : ps -ylC apache2 | awk ‘{x += $8;y += 1} END {print “Apache Memory Usage (MB): “x/1024; print “Average Proccess Size (MB): “x/((y-1)*1024)}’ This is particularly useful when you need to calculate proper process, max… Read More »
If you are accessing a computer using Remote Desktop (RDP) and try ripping an optical media (DVD, BD) using MakeMKV (or any other similar software for that matter), it will fail to access the disk. With MakeMKV, the error message will be as followed : The program can’t find any usable optical drive. This error… Read More »
Attempting to use the SAR (sadc) command to lookup the historical system resources consumption metrics and got the following message? Cannot open /var/log/sysstat/sa27: No such file or directory Please check if data collecting is enabled Most likely data collecting is disabled (it is the default on several systems). You need to enable data collecting and… Read More »
If you are experiencing issues with your local mail aliases, make sure there is no syntax error in /etc/aliases file and have a look at the mail log file : /var/log/mail.log You most likely will encounter a message like this one : postfix/local[15083]: warning: database /etc/aliases.db is older than source file /etc/aliases In that case,… Read More »
Having the following error while importing a MySQL dump? phpMyAdmin – Error Incorrect format parameter Have a look at the “upload_max_filesize” value in your “php.ini” parameters. Most of the time, the dump file you are trying to import exceed that limit. Increase the value as needed.
If you attempted to merge cells together within a table in Microsoft Excel, you may have faced the grayed out “Merge and Center” button issue. To work around this problem, do the following : 1. Select the cells that you want to merge 2. Right click on the selection 3. In the context menu, click… Read More »
If you changed the hostname/FQDN of a Linux server, you may end up with some issues, especially with mailing if some areas were forgotten with that change. Here is a quick procedure involving all the steps you should be looking for. (The following example is based on a Debian Linux system running Postfix MTA.) 1.… Read More »
This symptom occurred all of a sudden with Nmap 7.80 and Windows 10 version 1909 (OS build 18363.836), where nmap tries to query using interface “eth0” : Starting Nmap 7.80 ( https://nmap.org ) at 2020-06-30 11:28 Eastern Daylight Time dnet: Failed to open device eth0 QUITTING! It seems that latest Windows updates is involved in… Read More »
OpenVPN enforce by default a 15 minutes lockout policy for unsuccessful login attempts. As an avid system administrator and used to end-user struggles, you most likely encountered many times situations where a user tried to log in 20 times and blaming you that it isn’t working (all that because they are entering the wrong password,… Read More »