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DBA-C0131 · Capacity, Sizing & Licensing

Elasticsearch Shard Sizing

Sketch a shard count. Do not create the index. Do not set replicas to zero.

Updated 25 October 2026 · How-To

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

The calculator divides a size you type by a shard size you type. The count is a sketch. Creating the index is a later change, and this page does not create it.

Do not set the replica count to zero to save space. Security stays on. Do not publish port 9200.

192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. A sample password is replaced. It is not a password you keep.

The change you can finish

Apply nothing while you are writing the note. When the lab window opens, it is one change on the database named in the ticket. Read the draft, then the database, then decide.

Rollback is the backup, the file, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.

  1. Write the size you measured or say guess.
  2. Read the shard count.
  3. Leave replicas above zero.
  4. Do not create the index.
  5. Stop.

Mistakes that outlive the statement

Elasticsearch Shard Sizing goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.

Decisions to write down

One decision for Elasticsearch Shard Sizing: The count is labeled. Nothing was created. Replicas stay above zero. And security stays on.

Checks before you call it done

Confirm this before you call the change done: The index name is written or it is a sketch. The count was read. Nothing was created. Security stays on. And the database is yours. If one of those fails, stop.

Before you leave the database

Elasticsearch Shard Sizing ends when the database in the prompt is the database in the ticket. If it is not, you are on the wrong database. Stop.

The draft stays a draft until a person has read the names in it. A generator does not log into the database. You delete a line that names a host, a database, or an account you did not write down.

192.0.2.10, 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 database 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. A sample password in a draft is replaced. It is not a password you keep.

One change is the window. If two things move and the result is wrong, you will not know which one did it.

If the same step fails twice, stop for the day. Restore the copy you took first.

A second person reads the database name and the change aloud. If they cannot find them in the ticket, the note is not done.

This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a database you do not administer. You do not disable authentication, a firewall, or TLS to make a check pass.

Tools for this guide

These tools run in the browser on this site. They do not log into your machines.

More in this cluster

The pillar for this page, and the next published pages filed with it.