/var/log

/var/log/lastlog

contains the information about the last user that logged into the system.the information from this log is used by the lastlog utility

messages (system messages from syslogd),

/var/log/wtmp

stores the history of connections to the system.the information from this file is used by the last system utilities.


/var/log/btmp

this file stores information about un successful login attempts.the information from this file is used by the lastb command.

/var/log/daemon.log

all daemon facility messages


/var/log/dpkg.log

package management log


/var/log/dmesg

dump of kernel message buffer


/var/log/faillog

un-successful login attempts


/var/log/kern.log

all kernel facility messages


NB:-

/var/run/utmp

stores information about the current connections to the system.The information from this log file is used by who and w utilities







NB :- tested on ubuntu hardy