Monthly Archives: April 2016

Processes inside out

Multi-user and multi-tasking Now that we are more used to our environment and we are able to communicate a little bit with our system, it is time to study the processes we can start in more detail. Not every command starts a single process. Some commands initiate a series of processes, such as mozilla; others,… Read More »

The lsof command

The lsof command will print out a list of every file that is in use. Since Linux considers everythihng a file, this list can be very long. However, this command can be useful in diagnosing problems. An example of this is if you wish to unmount a filesystem, but you are being told that it… Read More »

The vmstat command

The vmstat command will provide a report showing statistics for system processes, memory, swap, I/O, and the CPU. These statistics are generated using data from the last time the command was run to the present. In the case of the command never being run, the data will be from the last reboot until the present.… Read More »

The ps command

The ps will provide you a list of processes currently running. There is a wide variety of options that this command gives you. A common use would be to list all processes currently running. To do this you would use the ps -ef command. (Screen output from this command is too large to include, the… Read More »

The iostat command.

The iostat will display the current CPU load average and disk I/O information. This is a great command to monitor your disk I/O usage. # iostat Linux 2.4.20-24.9 (myhost) 12/23/2003 avg-cpu: %user %nice %sys %idle 62.09 0.32 2.97 34.62 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn dev3-0 2.22 15.20 47.16 1546846 4799520 For 2.4 kernels the… Read More »

top command

The top command. The most common of these commands is top. The top will display a continually updating report of system resource usage. # top 12:10:49 up 1 day, 3:47, 7 users, load average: 0.23, 0.19, 0.10 125 processes: 105 sleeping, 2 running, 18 zombie, 0 stopped CPU states: 5.1% user 1.1% system 0.0% nice… Read More »

System and Administrative Commands

System and Administrative Commands The startup and shutdown scripts in /etc/rc.d illustrate the uses (and usefulness) of many of these comands. These are usually invoked by root and used for system maintenance or emergency filesystem repairs. Use with caution, as some of these commands may damage your system if misused. Users and Groups users Show… Read More »

Linux /proc

/proc is very special in that it is also a virtual filesystem. It’s sometimes referred to as a process information pseudo-file system. It doesn’t contain ‘real’ files but runtime system information (e.g. system memory, devices mounted, hardware configuration, etc). For this reason it can be regarded as a control and information centre for the kernel.… Read More »

LVM

LVM –  from https://wiki.archlinux.org/index.php/LVM Related articles Software RAID and LVM dm-crypt/Encrypting an entire system#LVM on LUKS dm-crypt/Encrypting an entire system#LUKS on LVM Resizing LVM-on-LUKS From Wikipedia:Logical Volume Manager (Linux): LVM is a logical volume manager for the Linux kernel; it manages disk drives and similar mass-storage devices. Contents  [hide]  1 LVM Building Blocks 2 Advantages 3… Read More »

Installing and Configuring Remote backup using Bacula on an Ubuntu 14.04

Installing and Configuring Remote backup using Bacula on an Ubuntu 14.04 Server Name : BackupServer Client Name : ClientMachine Client Installation $ sudo apt-get update $ sudo apt-get install bacula-client Client Machine Configuration $ sudo vim /etc/bacula/bacula-fd.conf (all below entried put in same file) search : “Director” section. Director { Name = BackupServer-dir #change Server… Read More »