Friday, September 4, 2009

Thursday, July 16, 2009

Problems && Solutions

  1. Problem: ssh login to one of the server was taking a long time (almost minutes).
  • Solution: The problem was solved by adding following lines at /etc/ssh/sshd_config:
UseDNS no

Friday, June 12, 2009

Monday, June 8, 2009

View actual physical memory usage on Linux

free

free command displays amount of total, free and used physical memory (RAM) in the system, as well as shoing information on shared memory, buffers, cached memory and swap space used by the Linux kernel.

Syntax of free

free -[options]

Example usage of free

free -m

The command will display information about physical memory in MB.

free -m -s 5

The command will activate continuous polling delay at 5 seconds apart, and then display memory status in megabytes on terminal. Any floating point number for delay can be specified.

free -t -m

Same with “free -m”, but -t switch will display a line containing the totals of physical memory and swap space.