Setting user logout time

How to set logout time for user in CLI mode
go to user's .baserc file and write TMOUT=60 save and exit
example......
[root@dinesh]‪#‎vi‬ /home/dhiman/.baserc
exmple
# .bashrc
...
# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi

# User specific aliases and functions
TMOUT=60
save and exit
login as user in cli terminal and enjoy the magic

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Setting user logout time

How to set logout time for user in CLI mode
go to user's .baserc file and write TMOUT=60 save and exit
example......
[root@dinesh]‪#‎vi‬ /home/dhiman/.baserc
exmple
# .bashrc
...
# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi

# User specific aliases and functions
TMOUT=60
save and exit
login as user in cli terminal and enjoy the magic

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what is difference between ext2 ext3 and ext4 ?

Ext2 stands for second extended file system.
- It was introduced in 1993. Developed by Rémy Card.
-This was developed to overcome the limitation of the original ext file system.
- Ext2 does not have journaling feature.
-Maximum individual file size can be from 16 GB to 2 TB
-Overall ext2 file system size can be from 2 TB to 32 TB
Ext3

... Ext3 stands for third extended file system.
-It was introduced in 2001. Developed by Stephen Tweedie.
-Starting from Linux Kernel 2.4.15 ext3 was available.
-The main benefit of ext3 is that it allows journaling.
-Journaling has a dedicated area in the file system, where all the changes are tracked. When the system crashes, the possibility of file system corruption is less because of journaling.
-Maximum individual file size can be from 16 GB to 2 TB
-Overall ext3 file system size can be from 2 TB to 32 TB
-There are three types of journaling available in ext3 file system.
Journal – Metadata and content are saved in the journal.
Ordered – Only metadata is saved in the journal. Metadata are journaled only after writing the content to disk. This is the default.
Writeback – Only metadata is saved in the journal. Metadata might be journaled either before or after the content is written to the disk.
-You can convert a ext2 file system to ext3 file system directly (without backup/restore).
Ext4

Ext4 stands for fourth extended file system.
-It was introduced in 2008.
-Starting from Linux Kernel 2.6.19 ext4 was available.
-Supports huge individual file size and overall file system size.
-Maximum individual file size can be from 16 GB to 16 TB
Overall maximum ext4 file system size is 1 EB (exabyte). 1 EB = 1024 PB (petabyte). 1 PB = 1024 TB (terabyte).
-Directory can contain a maximum of 64,000 subdirectories (as opposed to 32,000 in ext3)
-You can also mount an existing ext3 fs as ext4 fs (without having to upgrade it).
Several other new features are introduced in ext4: multiblock allocation, delayed allocation, journal checksum. fast fsck, etc. All you need to know is that these new features have improved the performance and reliability of the filesystem when compared to ext3.
In ext4, you also have the option of turning the journaling feature “off”.
thanks and regards dinesh dhiman

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How to communicate with base machine using kvm

Creating a bridge device

#brctl addbr "br0" <---------- bridge name 

after this
 
 Adding devices to a bridge

#brctl addif br0 eth0 <----------------hare eth0 is your physical interface
 
use this commands for show your bridge

#brctl show
 
enable stp on bridge

#brctl stp br0 on
 
now up the bridge

#ifup br0
 
than set ip address to bridge like this

#ifconfig br0 192.168.1.253 netmask 255.255.255.0

now select br0 during configure your kvm

configure ip address on kvm machine with range of same network

**************** i hope you Enjoy it ***************

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How to set Password Policy to let users Comply rules.

1 number of days for password Expiration.
2 Minimum number of days available of password.
3 number of days for warnings before expiration.
4 limit using a password that was used in past
5 Set minimum password length

open this file

# vi /etc/login.defs
 
(output of this file before changing )
 
16 #
17 PASS_MAX_DAYS 99999
18 PASS_MIN_DAYS 0
19 PASS_MIN_LEN 5
20 PASS_WARN_AGE 7
21 

edit this file like....

change line from 

17 PASS_MAX_DAYS 60
18 PASS_MIN_DAYS 2
19 PASS_MIN_LEN 6
20 PASS_WARN_AGE 2 <<< change all of these according to your need and 

at line number 16 enter this text

password sufficient pam_unix.so sha512 shadow nullok try_first_pass remember=5

save this file and exit

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