Category Archives: Operating Systems

Linux : kernel httpd invoked oom-killer

You have noticed such behaviour in the system logs (/var/log/messages)? kernel: httpd invoked oom-killer: gfp_mask=0x201d2, order=0, oomkilladj=0 kernel: Call Trace: kernel: [<ffffffff800cb67d>] out_of_memory+0x8e/0x2f3 kernel: [<ffffffff8002e493>] __wake_up+0x38/0x4f kernel: [<ffffffff8000a7ea>] get_page_from_freelist+0x2/0x442 kernel: [<ffffffff8000f6a2>] __alloc_pages+0x27f/0x308 kernel: [<ffffffff8001308d>] __do_page_cache_readahead+0x96/0x17b kernel: [<ffffffff800139d6>] filemap_nopage+0x14c/0x360 kernel: [<ffffffff80008972>] __handle_mm_fault+0x1fd/0x103b kernel: [<ffffffff8000c795>] _atomic_dec_and_lock+0x39/0x57 kernel: [<ffffffff800671ae>] do_page_fault+0x499/0x842 kernel: [<ffffffff8005ddf9>] error_exit+0x0/0x84 Additionally, the system was hanging/very… Read More »

Linux : Binary location for [/usr/bin/host] in csf.conf is either incorrect, is not installed or is not executable

The following error may occur while reloading CSF (csf -r) : *WARNING* Binary location for [HOST] [/usr/bin/host] in /etc/csf/csf.conf is either incorrect, is not installed or is not executable *WARNING* Missing or incorrect binary locations will break csf and lfd functionality In this particular case, CSF was installed on a CentOS 7 server and there… Read More »

Linux : How to show the complete installed package list on RHEL/CentOS?

Here is two useful commands to display all the installed packages and version in your RHEL/CentOS Linux system. 1. Display a comprehensive and formatted list using Yum :

2. Display the list of RPM package with their full name :

TIP : The suggestion #2 is a good way to provision a new… Read More »

Official Microsoft Windows 10 download link

Microsoft now provide and allow (officially) direct link for downloading their Windows 10 operating system from their Web site without any subscription. Prior Windows 10, ISO download was reserved to the store purchase and Service Providers Level Agreement (SPLA). Follow this link to get the official Windows 10 release : This will allow you to… Read More »