5.7 KiB
mc admin rebalance
minio
Table of Contents
mc admin rebalance
Permission
This command requires that the user performing it have the admin:Rebalance
policy action <minio-policy> for the
deployment.
Description
The mc admin rebalance command allows starts, monitors,
or stops a rebalancing operation on a MinIO deployment. Rebalancing
redistributes objects across all pools in the deployment.
MinIO does not automatically rebalance objects when adding a new
server pool. Instead, MinIO writes new objects <minio-writing-files> to the
pool with relatively more free space compared to the other available
pools on the deployment. Triggering a manual rebalancing procedure
prompts MinIO to scan the entire deployment and move objects as
necessary to achieve a similar available free space across all
pools.
This is an expensive and time consuming operation. Consider only running a rebalance procedure during light or no use of the deployment. If write operations do occur during a rebalance operation, they process in parallel and write to a pool not actively in rebalancing.
You can stop a rebalance and start it again later as needed.
Follow the progress of an ongoing rebalance operation using the following command:
mc admin trace --call rebalance ALIASUse mc admin on MinIO Deployments Only
The mc admin rebalance command has the following
subcommands:
| Subcommand | Description |
|---|---|
mc admin rebalance start |
Starts a rebalance operation on a MinIO deployment. |
mc admin rebalance status |
Outputs the current status of an in-progress rebalance operation. |
mc admin rebalance stop |
Stops an in-progress rebalance operation. |
Syntax
start
Start a rebalance operation for a MinIO deployment.
EXAMPLES
Consider a MinIO deployment with two pools with an assigned alias of
minio1. One pool has 250 GB of free space while the other
pool has 3 TB of free space.
The mc admin rebalance command shifts objects from the pool
with less free space to the pool with more free space so that there is
roughly equal free space on both pools.
mc admin rebalance start minio1SYNTAX
The command has the following syntax:
mc [GLOBALFLAGS] admin rebalance start ALIAS- Replace ALIAS with the
alias <alias>of a MinIO deployment to rebalance.
status
Queries the deployment with an active rebalance process and returns information about the status of the rebalance process.
The status returns the ID of the rebalance operation, the time of the operation, and details for each pool on the deployment. For each pool, the status shows the pool ID, the pool's rebalance status, the percentage of used space, and rebalance progress for the pool.
EXAMPLE
mc admin rebalance status minio1SYNTAX
The command has the following syntax:
mc [GLOBALFLAGS] admin rebalance ALIAS- Replace ALIAS with the
alias <alias>of the MinIO deployment.
stop
Ends an in-progress rebalance job on the specified deployment.
EXAMPLES
mc admin rebalance stop minio1SYNTAX
The command has the following syntax:
mc [GLOBALFLAGS] admin rebalance stop ALIAS- Replace ALIAS with the
alias <alias>of the MinIO deployment.
Global Flags
Behavior
Back Up Cluster Settings First
Use the mc admin cluster bucket export and mc admin cluster iam export
commands to take a snapshot of the bucket metadata and IAM
configurations respectively prior to starting decommissioning. You can
use these snapshots to restore bucket/IAM settings to recover from user
or process errors as necessary.
Rebalancing
Ignores Expired Objects and Trailing DeleteMarker
Starting with RELEASE.2023-06-23T20-26-00Z, rebalancing
ignores object versions which have expired based on the configured lifecycle rules <minio-lifecycle-management-expiration>
for the parent bucket.
Rebalancing also ignores objects where the only remaining version is
a delete marker <minio-bucket-versioning-delete>.
This avoids inter-pool I/O (Input/Output) for objects already considered
fully deleted.
MinIO relies on the scanner <minio-lifecycle-management-scanner> to
capture and remove those expired objects or trailing
DeleteMarker objects.