Category Archives: General

SSD wear and frequent small writes into MySQL DB

For about 2 years I used SSD as a system drive for my home server. It was mounted with noatime attribute and I knew there would be no services which can cause heavy write load on it. But recently I started a project which requires a small amount of data to be written in database each second or two. I guessed that such kind of load would increase ssd’s wear but I was unprepared to face how huge the wear is…

Recording h264 RTSP stream from surveillance camera using ffmpeg

For several years I used Vstarcam software (IP Camera Super Client) on Windows to record video stream from my cameras. This software (I preferred specific version 1.1.4.557) is quite reliable, though it produces video files that can’t be played by other video players. You can watch them only using this application. It was also painful […]

Why my last attempt to move to Linux has failed

As I mentioned in the post about Cinnamon power management, I decided to give Linux a try one more time. It happened after I had tried to install Windows 10 and those installation continued the whole night. Moreover, there was no any progressbar or something during the installation of OS and especially during the installation […]

Acer C720, its swollen battery and RTC.

A few days ago I pulled my Acer C720 out of the nightstand and noticed that it has a strange shape…
It’s keyboard was bulged toward the screen so the laptop can’t be closed completely.
Battery was swollen.
After I have removed the battery everything seems to work well except the wifi. Wifi couldn’t connect to anywhere and somehow I understood that the problem is incorrect date in RTC. RTC really had some fake date in the far future. It seems that there is no separate CMOS battery in this laptop. And I was needed to find the way to fix it.

Simple Perl CGI shopping list

In my family we often used pieces of paper to write down a list for the next grocery store visit.
I think this is a common situation and many people are using such lists.
After some time I have begun to feel some inconvenience because sometimes I forgot to take these lists to the grocery or I couldn’t understand a handwriting.
So I decided to do a simple web service on my own web server, that will serve as a shopping list.

Сalculation of the conformational potential energy surfaces of a molecular system using Hypercube Hyperchem and Microsoft Excel.

This is a post about my graduation thesis at the University. For now it seems simple and maybe not quite appropriate for such specialty as a physicist, but every measurement needs a scale. For an average student at those times and place it was a decent work and also these results were actually demanded by […]

Converting jqGrid filtering and sorting options to MySQL statements using Perl. And processing them.

Here I will describe a pattern that I used for a couple of years to pass filtering and sorting options from jqGrid to MySQL server.
JqGrig that is used here is simple. What I actually want to share is my two Perl subroutines – get_searchstring() and _get_filterops that allows to translate almost any filtering request from jqGrid to MySQL.
I can’t guarantee anything, you know, but these subroutines worked well for several years and didn’t manifest any glitches.