I noticed one bug with Mint Linux (Cinnamon) and Netbeans menu items that have an ‘active’ state which are completely invisible. Actually the text and the background colors are the same.
Mint 14 Nadia Cinnamon and later versions are affected (LMDE also) with NetBeans 7.3 and later.
The problem lies in the Mint-X GTK theme. To fix this problem, you need to modify /usr/share/themes/Mint-X/gtk-2.0/Styles/menu.rc file and lines
fg[ACTIVE] = @selected_fg_color
should be replaced with:
fg[ACTIVE] = @menu_fg_color
There are two lines (in style “menu” and style “menubar”)
Edit: 7. Aug. 2014.
The notes shown above doesn’t work on Mint 17 and it seems that Marco Moreno solved this problem
According to https://bugs.launchpad.net/linuxmint/+bug/1163030, you’ll need to change the /usr/share/themes/Mint-X/gtk-2.0/styles/menus.rc file.
Change line 53 from:
If you run “fdisk -l” and you get something like:
[root@ftp ~]# fdisk -l
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0xec2af3f7
Device Boot Start End Blocks Id System
/dev/sdb1 1 121601 976760001 83 Linux
Partition 1 does not start on physical sector boundary.
you’ll notice the message: “Partition 1 does not start on physical sector boundary”
What is the cause and do I need to fix it? If so, how?
Continue reading Partition X does not start on physical sector boundary
If you followed this recipe to install GitLab on CentOS, you may have some problems
Continue reading GitLab on CentOS – server certificate verification failed
A massive vulnerability has been found in OpenSSL, the open-source software package broadly used to encrypt Web communications. The flaw allows attackers to steal the information that is normally protected by SSL/TLS encryption (web applications, e-mail, instant messaging, VPNs, etc).
Essentially, that means a lot of Internet users are affected and passwords and credit card information could be available to hackers.
CentOS released the updated OpenSSL packages which should fix this issue.
# yum update openssl
# service httpd restart
For more information:
Here is a way to create a duplicate of one database, with all its tables and their data
Dump your source database into sql file
# mysqldump -uroot -p production -r production.sql
If you need only schema (database with empty tables)
# mysqldump -uroot -p production -r production.sql --no-data
Open up a MySQL shell and login as root
Create a new database and populate it with the dumped data
CREATE DATABASE production_copy;
Now if you like, you can create a new user and give it permissions to the new database
CREATE USER new_user IDENTIFIED BY 'some_password';
GRANT ALL ON production_copy.* TO 'new_user'@'localhost' IDENTIFIED BY 'some_password';
Note: this procedure works on Windows and Linux
Ethernet over IP (EoIP) Tunneling is a MikroTik RouterOS protocol (stateless and light ethernet point to point tunnel protocol with 28 bytes static overhead) that creates an Ethernet tunnel between two routers on top of an IP connection. The EoIP tunnel may run over IPIP tunnel, PPTP tunnel or any other connection capable of transporting IP.
To connect Linux with Mikrotik over EoIP tunnel, you’ll need THIS.
The install procedure:
# wget http://www.serveradminblog.com/wp-content/uploads/2016/03/linux-eoip-0.5.tar.gz
# tar -xvzf linux-eoip-0.5.tar.gz
# cd linux-eoip-0.5
# make install
Copy eoip.cfg to /etc dir, change settings inside according to your needs and save the file. If you use dynamic=1 option, take attention that there is no authorization,
and it is not secure. It is not good idea to use this feature with public ip or insecure(not completely under your control, each host) network.
For not lets suppose you need only one tunnel to remote IP address 188.8.131.52
On Mikrotik create EoIP tunnel with the same ID (1) and set your server’s IP address as remote IP. Run eoio with
# /usr/local/bin/eoip /etc/eoip.cfg
Add IP address to your eoip interface
# /sbin/ifconfig zeoip0 10.254.254.2 netmask 255.255.255.252 up
And optionally add routes (if you have any)
# route add -net 10.2.0.0/16 gw 10.254.254.1
Add the last few lines inside rc.local to enable tunnel after reboot. The eoip interface can be threaten just like any other interface.
zeoip0 Link encap:Ethernet HWaddr 5B:25:C9:44:6A:79
inet addr:10.254.254.2 Bcast:10.254.254.3 Mask:255.255.255.252
inet6 addr: fe80::5425:d9ff:fe80:6b79/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:167397 errors:0 dropped:0 overruns:0 frame:0
TX packets:138861 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:14934574 (14.2 MiB) TX bytes:12520192 (11.9 MiB)
# ps ax|grep dhcp
5180 ? Ss 0:02 /usr/sbin/dhcpd eth1 zeoip0
27356 pts/1 S+ 0:00 grep dhcp
As you can see, you can run dhcp server on eoip interface. Just open /etc/sysconfig/dhcpd and add DHCPDARGS=”eth1 zeoip0″ inside. Save the file and restart dhcp server.
I suppose you have a couple of clients who believes in Teamviewer only. Teamviewer on Linux works fine but after you install it, you’ll be supprised that the proces is always running in the background (it is build to respawn) which is ok if you’re the client who needs help. The first thing which average sys admin will do is to shut down teamviewer.
To stop teamviewer you can use:
initctl stop teamviewerd
To disable teamviewer on system startup you can use:
teamviewer --daemon disable
More info about the deamon you can find with:
boss init.d # teamviewer --help
teamviewer start TeamViewer user interface (if not running)
teamviewer --help print this help screen
teamviewer --version print version information
teamviewer --info print version, status, id
teamviewer --passwd [PASSWD] set a password (useful when installing remote (ssh)
teamviewer --ziplog create a zip containing all teamviewer logs (useful when contacting support)
teamviewer --daemon status show current status of the TeamViewer daemon
teamviewer --daemon start start TeamViewer daemon
teamviewer --daemon stop stop TeamViewer daemon
teamviewer --daemon restart stop/start TeamViewer daemon
teamviewer --daemon disable disable TeamViewer daemon - don't start daemon on system startup
teamviewer --daemon enable enable TeamViewer daemon - start daemon on system startup (default)
If you’re using PHP 5.2.x on RHEL/CentoOS and you received error
PHP Fatal error: Call to undefined function sqlite_escape_string()
don’t worry. The reason for this is the missing sqlite extension which is not included in RHEL/Fedora/CentOS php packages by default.
To fix this issue, you can include it manually
tar xzvf php-5.2.XX.tar.gz
echo extension=sqlite.so >> /etc/php.d/sqlite.ini
service httpd restart
Replace XX with your PHP version (check the php version with “php -v”)
Since the Oracle bought Sun (including MySQL), I wanted to improve my knowledge about other databases and to check the alternatives (in case “something” happens to MySQL).
Luckily, MySQL is still here and it still works fine but in the last couple of months, I wanted to dig a little bit about PostgreSQL. I thought that it would be easy to find online tutorials about this topic but I noticed that online tutorials and forums about PostgreSQL are not so popular. Don’t get me wrong, there are several blogs which fits perfectly in my learning habits but spending so much time just to find the basic things is not what I wanted.
I found a link about Packt Publishing free PostgreSQL backup e-book and I didn’t wait (LINK). I posted a comment and couple days later received Packt account with two books
Instant PostgreSQL Starter by Daniel K. Lyons was exactly what I was looking for. A small (48 pages) book was right away uploaded to my DropBox so I can have it where ever I go. The book covers everything you need to start with Postgresql.
You will learn how to install Postgresql, how to connect and create your first database. The book also covers basic SQL queries for creating tables, CRUD (create, read, update and delete records), etc. The last part of the book contains some features you should also know (how to store passwords, working with XML, Full text search and basic options for improving speed and security). Couple advices about backups are also there.
Using pgAdmin III as a GUI tool won’t be a problem because the book contains pgAdmin screenshots.
Don’t get me wrong…. The book has only 48 pages and it can be compared with a cheat sheet but it is a very good portable book. Learning Postgresql can take only one afternoon and in less than a weekend you’ll became a “usable” DBA.
After the Postgresql starter book, I switched to PostgreSQL Backup and Restore How-to. We usually like to say that backup doesn’t have the price and every DBA should know everything about creating and restoring backups.
This (55 page) book is a step-by-step guide to backing up and restoring your database which covers:
- basic and partial exports,
- simple restore,
- creating and restoring binary backups,
- compressing backups
- taking snapshots
- sync backups
- point in time recovery
- warm and hot standby restore
- streaming replication
Just like the first book, this one is also uploaded to my DropBox. Having those books with you is a nice idea and I highly recommend them to all Postgresql beginners. You can buy them as an e-book and as a hard copy.