The Best Docker Tutorial for Beginners
We quickly explain the basic Docker concepts and show you how to do the most common tasks from starting your first container, to making custom images, a Docker Swarm Cluster Tutorial, docker compose and Docker buildfiles.........
Occasionally my whole screen locks up and I cannot even swith to the console and I find this in my syslog:
*-display
description: VGA compatible controller
product: Mullins [Radeon R3 Graphics]
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
 ........
Essentially a program I was running for mining did not terminate properly with Ctrl+C it is listed as defunct and cannot be killed, kernel is tainted and normal tricks to disable the port are impossible the dev and sys entries for the device cannot be browsed or interacted with in any form without a lockup of the request. The only solution is to reboot due to the kernel taint as far as I can find so far.
[1130246.811056] INFO: task minerd:21861 blocked for more th........
This is a 8TB Seagate external USB 3.0 device apparently newer kernels use a module called "UAS" instead of "USB Storage" which causes issues as a lot of devices are not properly supported in UAS mode by the kernel driver. The solution some say is to disable UAS specifically for your USB device but I'd rather just disable UAS altogether.
Solution blacklist UAS: *do not do this it does not work and just causes your USB 3.0........
Using Apache 2.2 and PHP5.6 PHPBB3 is very slow to respond. Actually for some reason it takes so long to even register a log entry in access_log as in several seconds or a few minutes later it shows up in Apache. All other vhosts and Apache access stops working and freezes until the request to access PHPBB3 slowly completes.
It seems to randomly be slow if you stop using it whether for posting or reading the forums. I've migrated to different machines including........
Tired of checking iotop and seeing that your drbd partition is using 99.99% of io all the time and finding your drbd device performs slow in general?
This is especially an issue in versions of DRBD in the 8.3 tree in particular one documented case is on "8.3.13" but it likely applies to other devices.
The symptoms are that resyncing is fine and normal but any reasonable amount of activity is very slow and lagged and creates a high server load and con........
This happened while an mdadm array was syncing, all access from writing a new blank file to opening a small .txt file was very slow:
[222117.312078] kjournald starting. Commit interval 5 seconds
[222117.685060] EXT3-fs (md0): using internal journal
[222117.685096] EXT3-fs (md0): mounted filesystem with ordered data mode
[222122.376847] kjournald starting. Commit interval 5 seconds
[222122.602825] EXT3-fs (md2): using internal jour........
mod_status is a great way to track down the source of high CPU usage and to find what vhost/script is the cause of it.
It gives you a live view of bandwith usage, CPU usage, and memory usage broken down by domain/vhost and script/URI.
Enable mod_status
vi /etc/httpd/conf/httpd.conf
ExtendedStatus On
SetHandler server-status
Order Deny,Allow
Deny from all
All........