What is the major difference between Apache Cassandra, Apache HBase and MongoDB NoSQL Database environment? Which of them run on Hadoop Distributed Filesystem (HDFS)? Which provide for faster and easier integration of data in applications? What language are the three written? In term of performance, which can handle large amount of data most?

What is the difference between Lyx editor and LaTex? What distinctive features are in Lyx editor that are not in other text / word processing software? Who is Lyx editor design for? How best can novice customize Lyx editor for own use? in learning to use Lyx Editor, what are paramount?

How can I convert FAT formatted drive to NTFS without loss of data? I have a large drive that was formatted in FAT which is v unstable and now I want to convert it to the stable NTFS file system without me losing any of my data in the FAT drive. What tools are available for this task? I don’t want to use window convert command because of data loss.

What is the difference between cloning and Imaging a Hard Drive? I want to back up my Hard Drive so that in case of an accident, I can quickly retrieve my documents and files but choosing the best approach is far from easy. When do I use cloning or when do I use imaging? What are the pros and cons of the two?

What is the relationship between storage space, Random Access Memory (RAM) and CPU with respect to apache Cassandra? According the apache Cassandra 2.1.2 node configuration, maximum recommendation capacity is 3 to 5 terabyte per node, if am running this maximum load of data, will I have to increase the RAM? If the RAM is not increased, will it affect the throughput and latency?

what are the various ways to evade countries or individual censorship of some certain website? With the recent great China firewall blocking of Gmail and other Google services in China, many countries may be embolden to crack down hard on decedent or civil activists in their countries. What are the more secure ways in accessing internet without being notice?

What are the tools for converting windows NTFS to Linux ext4? I am running a dual boot with both window 8 and Linux Ubuntu, now I want to convert the window NTFS to Linux ext4 because am running low on disk space in the Linux partition. What tools can I use for the conversion keeping my NTFS data intact?

Why are the two monitors I set on my system not working? I need to use two monitor with my Laptop. I am running some analysis that require a large screen and I don’t want to spend on another monitor with large screen, thereby leaving me with no option than to use two monitor. I have set up the two monitors, but the other monitor is not working; only the main monitor is working.

How do I set up fail2ban to secure Ubuntu server? I recently install the latest fail2ban (Version 0.9.1 release) to secure Ubuntu X64 server, I have whitelist the administrator Ip range but am sure it may not be secure. Is it possible to set up fail2ban to ignore dynamic IP other than the default ‘ignoreip’? If not, what other secure option can I use to achieve this goal?

Why is OS X Yosemite not running on my mac laptop? I have been trying to install OS X Yosemite on my mac laptop but the installation always fails. My mac laptop meet all the OS X Yosemite recommended system requirement. What could be preventing the OS from running? How can I fix this issue?