This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.
What this hour is for
ext4 is the ordinary default and can grow and shrink with the tools that know it. XFS is common on large volumes and does not shrink the way ext4 does. Btrfs and ZFS add checksums and snapshots and a different way of operating. The selector records a choice. The mkfs builder drafts a format command. It does not run it.
mkfs destroys what is on the device. The device in the draft is an empty lab disk, or the command stays a draft. Do not format a disk because the comparison made one filesystem look newer.
This page is not a benchmark and not a promise about speed. 192.0.2.10/24 and example.com are documentation. They stay in the note.
The change you can finish
Apply nothing while you are writing the note. When the lab window opens, it is one change on the host named in the ticket. Read the draft, then the host, then decide.
Rollback is the file, the package version, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.
- Name the disk and whether it has data.
- Write the feature you need: shrink, snapshot, or ordinary files.
- Pick one filesystem.
- If you draft mkfs, point it at an empty lab name only.
- Do not run mkfs.
- Stop.
Mistakes that outlive the command
ext4 vs XFS vs Btrfs vs ZFS goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- mkfs on a disk that has data.
- XFS chosen and then a shrink assumed.
- A benchmark treated as a promise.
- Two filesystems started in one hour.
Decisions to write down
One decision for ext4 vs XFS vs Btrfs vs ZFS: One filesystem. Shrink is a requirement only if you wrote it. mkfs was not run. The disk with data was not the target. And the choice is a sentence.
Checks before you call it done
Confirm this before you call the change done: The filesystem is named. The shrink or snapshot need is written. No format was run. The data disk is excluded. And a second person can repeat the reason. If one of those fails, stop.
| Filesystem | Ordinary note | Watch |
|---|---|---|
| ext4 | A common default | You still choose it on purpose |
| XFS | Large volumes | Do not plan to shrink it |
| Btrfs | Checksums and snapshots | A different operation |
| ZFS | Checksums and snapshots | Memory and the pool are a design |
# mkfs destroys the device you name.
# Do not format a disk that has data.
# XFS is a poor choice if you must shrink.Before you leave the host
ext4 vs XFS vs Btrfs vs ZFS ends when the hostname in the prompt matches the hostname in the ticket. If it does not, you are on the wrong host. Stop. A command that succeeded on the wrong host is not progress.
The draft stays a draft until a person has read the names in it. A generator does not log into the host and does not know which disk is empty. You delete a line that names a host, a path, or an account you did not write down.
192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a host because a draft included them.
prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save in the ticket or in git. The real secret stays in the password store.
One change is the window. If two things move and the result is wrong, you will not know which one did it. The next change waits for its own page.
If the same step fails twice, stop for the day. The failure is the result. Adding a forum command beside a half-applied change produces a host nobody can rebuild. Restore the copy you took first.
A second person reads the hostname and the change aloud. If they cannot find them in the ticket, the note is not done. Silence is not agreement. Then leave the host alone.
This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a host you do not administer. You do not disable a firewall, AppArmor, or SELinux to make a check pass.
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