debug-ballast.md

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Create a Ballast File	Create a large, unused file in a node's storage directory that you can delete if the node runs out of disk space.	true

The debug ballast command creates a large, unused file that you can place in a node's storage directory. In the case that a node runs out of disk space and shuts down, you can delete the ballast file to free up enough space to be able to restart the node.

• In addition to placing a ballast file in each node's storage directory, it is important to actively monitor remaining disk space.
• Ballast files may be created in many ways, including the standard dd command. cockroach debug ballast uses the fallocate system call when available, so it will be faster than dd.

Subcommands

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Synopsis

Create a ballast file:

$ cockroach debug ballast [path to ballast file] [flags]

View help:

$ cockroach debug ballast --help

Flags

Flag

Description

--size -z

The amount of space to fill, or to leave available, in a node's storage directory via a ballast file. Positive values equal the size of the ballast file. Negative values equal the amount of space to leave after creating the ballast file. This can be a percentage (notated as a decimal or with %) or any bytes-based unit, for example: --size=1000000000 ----> 1000000000 bytes --size=1GiB ----> 1073741824 bytes --size=5% ----> 5% of available space --size=0.05 ----> 5% of available space --size=.05 ----> 5% of available space

Example

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$ cockroach debug ballast cockroach-data/ballast.txt --size=1GiB

See also

• Other Cockroach Commands
• Troubleshooting Overview
• Production Checklist