I know there are tones of information about how and what to use to analyze the memory usage on linux.
However I’m publishing some useful ones that can be helpful to start with:
Display amount of free and used memory
free -m
Display swap usage summary
swapon -s
Display user-process resource limits
ulimit -a
List processes sorted by memory usage
ps aux –sort -rss
Trying to mount -a on a linux system with windows share was giving me the following error
mount: Cannot allocate memory
The problem seems to be on Windows system where share is located. Quick and temporary workaround is to restar Lanmanserver service and retry mount -a.
Permanent fix that should help is to edit a registry setting and restart the service as below:
reg add HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters /v Size /t REG_DWORD /d 3 /f
sc stop LanmanServer
sc start LanmanServer
grep searches the input files for lines containing a match to a given pattern list. When it finds a match in a line, it copies the line to standard output (by default), or does whatever other sort of output you have requested with options.
grep can simply be invoked: $ grep ‘STRING’ filename
Run the date command to make sure you have the correct time:
[root@server /root]# date Thu Sep 20 11:00:06 CDT 2001 [root@server /root]#
If your timezone is correct but the date and/or time needs updating, the following commands will update the date and time. The second command is needed in order to push the date and time into the PC clock.
[root@server /root]# date 092011082001 Thu Sep 20 11:08:00 CDT 2001 [root@server /root]# hwclock --utc --systohc [root@server /root]#
I’ve finally got new hdd for my laptop. So I decided to dedicate myself on getting to know more about Desktop version of Ubuntu. Latest copy was installed successfully without any troubles except driver for Nvidia. But that was easily solved by downloading and installing latest driver.
SSH (Secure Shell) is a protocol for creating a secure connection between two computers.The secure SSH connection provides authentication and encryption. SSH also provides compression and is most common way for users and root to get connect to the server (Linux), the main reson behind blocking the root user is to allow the admin to login into the box with the default normal user and do the the administrator task using sudo, no direct root login.
1. vi /etc/ssh/sshd_config
3. Locate the parameter — PermitRootLogin yes
4. Change this to PermitRootLogin no
5. Save and exit
6. Restart your sshd by type sudo /etc/init.d/ssh restart
Here is a very cool and beautiful representation of the hierarchy which I found @linuxconfig.org site. The diagram below represents (part of) a Linux file system.
It is important to have the system updated, so that we have all the latest patches, security fixes and packages upgrades from the repositories.
First, navigate to: System –> Administration –> Software Sources
and check that all repositories are enabled.
Then, open the terminal: Applications –> Accessories –> Terminal
and type: (you need to provide the password here)
sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
With this you are done with the system update.