Ubuntu

Create a Good Password using Terminal

Posted on by coder
If you’re not the best at making passwords or just don’t want to make one up right off the spot, you would usually run third party applications to generate a good password for you.

Why download third party apps when you already have a password generator for you just waiting to be used in the Terminal?

To create a password:

1. Access Terminal. Username>Applications>Utilities>Terminal
2. On the line provided, write openssl rand -base64 6.
3. Terminal will generate an eight character password for you.

 

best pdf reader for ubuntu

Posted on by coder

Evince is the default PDF viewer in most GNOME-based Linux distributions, so if you don’t want to install all those KDE dependencies, Evince is probably your next choice. It’s lightweight, simple, and easy to use, though it doesn’t have too many advanced features. You can rotate PDFs, add bookmarks, and change the sidebar’s view mode, but other than that, you don’t have much. If all you’re doing is reading the occasional PDF, it’s great, but you won’t find any annotation features here.

Adobe Reader has a Linux version available, and as always, we don’t recommend it as your go-to reader. That said, it’s still the standard, which means if you ever have compatibility issues in something like Okular or Evince, Adobe Reader will probably handle it just fine. You don’t need to install it now, just know that if you ever have problems, it’s worth keeping in mind.

Lastly, it’s worth noting that lots of Windows PDF apps work great under WINE, including PDF X-Change, Foxit, and Sumatra. So, while they won’t look fantastic under Linux, they’re great if you need some more advanced reading and editing tools, since most Linux apps are a bit lacking.

These aren’t the only PDF viewers for Linux, but they are, in our opinion, the best. If you’ve got a favorite we didn’t mention, let us know about it in the comments.

Ubuntu Performance Tuning

Posted on by coder

The overall performance of Ubuntu Linux is fine but to further tune the following can be done :

1. If you are not using IPv6 it can be disabled as follows:

In /etc/modprobe.d/aliases change the line alias net-pf-10 ipv6 into alias net-pf-10 off #ipv6.

2. Start daemon/processes in parallel

Change /etc/init.d/rc from CONCURRENCY=none in CONCURRENCY=shell

3. Add your hostname in the host file (default on hardy & intrepid). If you add your host name to the /etc/hosts file some apps will start quicker. e.g. 127.0.1.1 myhostname

4. Install preload. Startup times on apps. can be further improved by installing preload (apt-get install preload)

5. Decrease Swappiness setting

If you got plenty of ram (>1GB) you can decrease the use of the swap file by changing the vm.swappiness sysctl entry from 60 to 10. If you like to further reduce swapfile usage you can set this value to 0* which will not disable swapfile usage but will reduce it to the absolute minimum. To change the sysctl entry *sysctl vm.swappiness=10 can be used, to let this setting survive a reboot vm.swapiness=10 can be added to the /etc/sysctl.conf file.

I’ve found that the value of 5 works very good for my use and I have 2 GB of memory.

6. Use the profile option of grub to reduce startup time.

Hit the escape button when booting to get to the grub menu, select the default kernel and select edit, add the profile option to the end of the kernel line and boot your system.

8. Disable unused services.

9. Use the noatime mount option to disable updating the access time on files.

If you have additional tips I’m more then willing to test/add them to this list.

This section covers some of the most common DNS record types.

Posted on by coder

A record: This record maps an IP Address to a hostname.

www IN A 192.168.1.12

CNAME record: Used to create an alias to an existing A record. You cannot create a CNAME record pointing to another CNAME record.

web IN CNAME www
MX record: Used to define where email should be sent to. Must point to an A record, not a CNAME.

IN MX mail.example.com.
mail IN A 192.168.1.13
NS record: Used to define which servers serve copies of a zone. It must point to an A record, not a CNAME. This is where Primary and Secondary servers are defined.

IN NS ns.example.com.
IN NS ns2.example.com.
ns IN A 192.168.1.10
ns2 IN A 192.168.1.11