Linux · Filesystems & Mounting

After a server has run for a week, free shows swap in use even though gigabytes of RAM are free. Does this mean you're short on RAM, and why does it happen?

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More in Filesystems & Mounting

Partitioning a disk reserves space, yet you still can't store files on that space until you do one more step. What is that step called, and what does it actually add?

Someone assumes every Linux install uses the same file system. Which type is the most common default for general Linux use, and when would you reach for xfs or btrfs instead?

You spin up a server on RHEL and never picked a file system during install. Which one did you get by default, and why does that choice fit servers?

btrfs is the default on Fedora and SUSE, so a smart guess is that RHEL supports it too. What's actually true on RHEL, and since when?

A swap partition doesn't hold a normal file system, yet you still can't just point the kernel at fresh swap space and use it. What preparation is required, and who normally does it?

You run df on a busy system and the output is cluttered with tmpfs and snap entries you don't care about. Which command gives human-readable sizes while hiding those internal file systems?

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