04 September, 2019

Automatically restoring running VirtualBox VMS after restart

VirtualBox has a built in solution for automatically starting and stopping vitual machines, as it is well explained in this post. However, I have a lot of virtual machines, and depending on what I am doing a different set of machines are running. I am not in a critical environment, therefore my vm host is set to automatically install updates, and if needed restart. In order not to loose the virtual machines I have written a small systemd service, which on shutdown saves all running virtual machine states and on restart starts them again.

Disabling Graphical Boot on Ubuntu Server 1804

An a server it has no advantage the GRUB and the Linux kernel is booting up in graphical mode, as it is only hiding the potential error messages.

The following is a simple receit to switch it off.

06 August, 2019

Linux mdraid device names not kept after reboot

We all know that to have the array device names persist you have to do:

 mdadm --detail --scan >>/etc/mdadm/mdadm.conf

However this is not enough, this has to be also updated in initram, so the easiest way to do it, is by running:

dpkg-reconfigure mdadm

This will automatically update the initram.

(I do not mention here, that after piping the array list to /etc/mdadm/mdadm.conf, it is very practical to manually check if everything is correct, to avoid duplicate arrays or old not-any-more existing arrays.)

TGT adding iSCSI targets with spaces in their name

Using iSCSI is very usefull even in home environments. In Linux on the server side you can use TGT for this purpose, usually you can manage it weasily with Webmin, but I did not found the correct way to add a file name with spaces to the /etc/tgt/targets.conf.

So finally I maked a symlink to the file and added the link to the config file and it workied.

ln -s /media/disk/file\ with\ spaces\ in\ name.img /home/user/iscsitarget

And put the /home/user/iscsitarget in yout TGT config file.

30 July, 2019

Benchmarking 3 disk RAID array speeds

I have experienced very poor performance on the RAID set up on my new computer, so I decided to do a short test of the speed and capacity of different RAID configurations.

18 June, 2019

Moving Outlook contacts to Google Contact with pictures

Sometimes you may need to move your contacts from Outlook to your Google account. Most sites recomend doing an Outlook export to csv and then import it to Google Contacts, but that doesn't transfer your pictures, and if you are not using English language, you have to play arround with the field names.
Here is an easy way to transfer your contacts with all details.

21 August, 2018

Linux Storage LAB: Using OpenDedup to store VM virtual images

Deduplication means, that when saving data to disks, if the same data is stored once more, then only a reference is stored and space is saved. OpenDedup is an open source online (real-time) deduplication solution, with one of the goals to provide a solution for storing Virtual Machine images, where big parts of the images could be duplicated. In this article we test OpenDedup, both from speed and compression point of view.

03 July, 2018

Linux Storage LAB: Extending Raid volume in LVM

This is a test performed on an Ubuntu 1604 virtual machine, to verify, how you can expand a SW RAID, which is used trough an LVM by a file system, without losing data.

15 March, 2018

EXIF Tagging and international caracter sets

I have just scanned approximately 2000 slides from my parents and I decided to tag them, to make it easier to search among them. The goal is to store the tags inside the jpg files, and to be standardized, not dependent on any specific software. The first idea is to use the standard EXIF fields for this purpose.

Custom Firmware on Lenovo P70A

I have been using my Lenovo P70A for almost one year until now, but recently I get more and more feedback from my partners, that they do not hear what I am saying, when we are talking over the phone. This is some kind of audio problem of the phone, so I thought that this can be fixed by upgrading the firmware of the phone,  so I started to experiment with custom firmware. In this blog I explain all the details of upgrading firmware, making backup of your actual firmware and data, and about the tools related to the firmware upgrading.

Virtual Box on Ubuntu Desktop 1604

Oracle VirtualBox runs well on Ubuntu 1604 host, but you should know how to set it up to have a good user experience with it.

It this article I will show you 4 pitfalls, and how to avoid them.

1. Default installations fails referring to kernel module failed
2. Can not connect remotely with RDP
3. Windows guest display is flickering/unity menu overlaps guest full screen
4. Can not set second screen to full screen

03 April, 2017

Restoring MTK based phones from Sp Flash Tool Readback image

It is very easy to back up an MTK based phone with SP Flash Tool, but restoring is not so easy. For older chip versions MTKDroidTools was an automatic tool, but with newer ones it is not working anymore. Keep reading, to learn, how to create a flashable image from the backup you made with SP Flash Tool.

20 March, 2016

Fixing keyboard and mouse not working in a virtual machine

I have some old Microsoft Virtual PC Windows XP images and wanted to test them and use them under VMWare Player. To my surprise after creating a new virtual machine and adding the virtual hard disks Windows XP started without any problem, but the mouse and the keyboard was absolutely not working.

14 November, 2015

Intel SS4200 processor upgrade and speed benchmark

I have an Intel SS4200 home storage server running Ubuntu 14.04 server at home, and because the read speeds were only around 60 Mbyte/sec, I decided to do a processor upgrade. After the upgrade I had some problems with the fan, and the speed did not significantly increased. Read more for the details.

28 October, 2015

Setting up a 4G modem with network USB emulation with OpenWRT on the MPR-L8 or A5-V11

In my previous post, I have explained how to setup a 3G/4G modem with USB connection emulating a serial device, in this post I will explain, how to set it up with a modem emulating network connection on the USB interface, like the ZTE MF-821D. The same method applies if you want to use an Android phone as a modem.