The `apt update` and `apt upgrade` commands are commonly used in package management on Debian-based systems like Ubuntu. Here’s what each command does:
1. `apt update`: This command updates the local package index. It retrieves the latest information about available packages from the software repositories configured on your system. Running `apt update` ensures that your system has the most up-to-date information about package versions and dependencies. However, it does not upgrade any installed packages.
It is recommended to run `apt update` before performing package installations or upgrades to ensure that you have the latest package information from the repositories.
2. `apt upgrade`: This command upgrades the installed packages on your system to their latest available versions. It considers the updated package information obtained from `apt update` and installs any available updates for the installed packages. The upgrade process takes into account package dependencies and performs necessary changes to keep your system up-to-date.
Running `apt upgrade` may prompt you to confirm the installation of new packages or the removal of obsolete packages. It is a good practice to review the proposed changes before proceeding.
In summary, `apt update` refreshes the local package index with the latest package information, while `apt upgrade` installs the latest available versions of installed packages on your system.
Should do apt upgrade after apt update
Yes, it is generally recommended to run `apt upgrade` after running `apt update` to ensure that your system is up-to-date with the latest package versions.
Here’s the recommended sequence:
1. Run `apt update` to update the local package index and retrieve the latest package information from the repositories.
2. After `apt update` completes successfully, you will have the most up-to-date information about available package versions.
3. Run `apt upgrade` to upgrade the installed packages on your system to their latest available versions, based on the updated package information obtained from `apt update`.
By running `apt upgrade` after `apt update`, you ensure that your system benefits from the latest bug fixes, security patches, and new features provided by the updated packages. It helps keep your system secure and up-to-date.
Note that running `apt upgrade` may prompt you to confirm the installation of new packages or the removal of obsolete packages. It is a good practice to review the proposed changes before proceeding to ensure they align with your system requirements.
Remember to exercise caution when performing system updates and ensure you have appropriate backups or system snapshots in place, especially for critical systems or production environments.
Thanks for this post. It is also important to mention that you may use
`sudo apt-mark hold “*”`
to hold a package from being upgraded. This is often done in software development environments where a new version can cause a product not to work properly.
To see what is currently on hold:
`sudo apt-mark showhold “*”`
To remove a hold:
`sudo apt-mark unhold “*”`