What is lastlog in Linux?
lastlog is a program available on most Linux distributions. It formats and prints the contents of the last login log file, /var/log/lastlog (which is a usually a very sparse file), including the login name, port, and last login date and time.
Why is lastlog so huge?
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).
How use lastlog command in Linux?
In order to find last login times for all users on your Linux machine, you can use the “lastlog” command with no options. By default, you will be presented with the list of all users with their last login attempts. Alternatively, you can use the “-u” option for “user” and specify the user you are looking for.
Why is lastlog a sparse file?
/var/log/lastlog is a binary file that holds information about the last time that users logged in to the system. The lastlog file is a sparse file, which means that the apparent size reported by “ls -l” is larger than the actual disk usage of the file(du), because not all blocks in the file are allocated on disk.
Can we delete lastlog?
On the Linux systems there are three standard commands that show the information about last logged in users: last , lastb , and lastlog ….HowTo: Clear or Remove Last Login History in Linux.
| Command | Logfile | Description |
|---|---|---|
| lastb | /var/log/btmp | Shows the bad login attempts |
| lastlog | /var/log/lastlog | Shows the most recent login |
Can I delete lastlog in Linux?
Task: Clear all last login information by deleting the /var/log/lastlog.
Can we delete lastlog file in Linux?
This is binary file and act as database times of previous user logins. You need to use lastlog command to formats and prints the contents of the last login log /var/log/lastlog file. This page explains how to clear or erase last login records on Linux based systems….Linux Remove or Clear the Last Login Information.
| Tutorial details | |
|---|---|
| Est. reading time | 3 minutes |
How do I disable lastlog?
how do i disable writing to /var/log/lastlog file. In our system we had to use a vfat file system for /var/log and since it doesn’t support sparse files, our lastlog file gets real huge….1 Answer
- Make the file immutable with chattr.
- ln -s it to /dev/null.
- Delete it and create a directory with the same name.
What does var log lastlog do?
The /var/log/lastlog file is used to store information about the successful logins to the host. On several versions of RedHat Enterprise Linux and Fedora, corruption in this file can cause the size to be misrepresented. This has no effect on the real space used by the file, as reported by the du command.
Can I remove lastlog in Linux?
On the Linux systems there are three standard commands that show the information about last logged in users: last , lastb , and lastlog ….HowTo: Clear or Remove Last Login History in Linux.
| Command | Logfile | Description |
|---|---|---|
| lastlog | /var/log/lastlog | Shows the most recent login |
Can we delete lastlog file?
Most likely you do not need to clear lastlog or be concerned with how much it is being written to at all. lastlog is a binary file that contains information about the last time a user logged in, I would always recommend copying the file to a partition that has more storage and compressing it prior to clearing it.