Why is Lastlog so large?
Answer. The file is a sparse file and is not actually taking up as much physical space as it shows. lastlog records the last login of each user. The large size merely shows you the potential size of the file if there were a maximum amount of users (around 2^32 users).
What is in var log messages?
/var/log/messages – This file has all the global system messages located inside, including the messages that are logged during system startup. Depending on how the syslog config file is sent up, there are several things that are logged in this file including mail, cron, daemon, kern, auth, etc.
What is var log wtmp?
Wtmp is a file on the Linux, Solaris, and BSD operating systems that keeps a history of all logins and logouts. On Linux systems, it is located at /var/log/wtmp. Various commands access wtmp to report login statistics, including the who and lastb commands. Log, Operating system, Operating System terms.
How do I open a wtmp file in Ubuntu?
We can also use the last command to read the content of the files wtmp, utmp and btmp as well. For example: # last -f /var/log/wtmp ### To open wtmp file and view its content use blow command. # last -f /var/run/utmp ### To see still logged in users view utmp file use last command.
Why is / var / log / lastlog used for lastlog?
/var/log/lastlog is used for lastlog command, modifying the permissions of this file will lead to similar errors for lastlog command only. There is no private information in such files, and I find useful to find which user are logged and when they logged in my machines (active users), e.g. before to make a reboot.
What’s the difference between kern.log and / var / log / syslog?
Syslog can also save logs to databases, and other clients. According to my /etc/syslog.conf, default /var/log/kern.log captures only the kernel’s messages of any loglevel; i.e. the output of dmesg. /var/log/messages instead aims at storing valuable, non-debug and non-critical messages.
What’s the difference between var / log / messages and journald?
This is relevant because you won’t be finding /var/log/messages that often anymore. journald doesn’t write plaintext logs — it uses its own, compressed and partially authenticated format. Search online for e.g. journalctl cheatsheet, or just study man 8 systemd-journald, man 1 journalctl yourself.
How to transport logs between syslog and journald?
Search online for e.g. journalctl cheatsheet, or just study man 8 systemd-journald, man 1 journalctl yourself. Syslog and journald are, to a degree, cross-compatible; you can transport logs between them in either direction.