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# Bring a demoted primary node back online **(PREMIUM ONLY)**
After a failover, it is possible to fail back to the demoted **primary** node to
restore your original configuration. This process consists of two steps:
1. Making the old **primary** node a **secondary** node.
1. Promoting a **secondary** node to a **primary** node.
CAUTION: **Caution:**
If you have any doubts about the consistency of the data on this node, we recommend setting it up from scratch.
## Configure the former **primary** node to be a **secondary** node
Since the former **primary** node will be out of sync with the current **primary** node, the first step is to bring the former **primary** node up to date. Note, deletion of data stored on disk like
repositories and uploads will not be replayed when bringing the former **primary** node back
into sync, which may result in increased disk usage.
Alternatively, you can [set up a new **secondary** GitLab instance][setup-geo] to avoid this.
To bring the former **primary** node up to date:
1. SSH into the former **primary** node that has fallen behind.
1. Make sure all the services are up:
```sh
sudo gitlab-ctl start
```
NOTE: **Note:** If you [disabled the **primary** node permanently][disaster-recovery-disable-primary],
you need to undo those steps now. For Debian/Ubuntu you just need to run
`sudo systemctl enable gitlab-runsvdir`. For CentOS 6, you need to install
the GitLab instance from scratch and set it up as a **secondary** node by
following [Setup instructions][setup-geo]. In this case, you don't need to follow the next step.
NOTE: **Note:** If you [changed the DNS records](index.md#step-4-optional-updating-the-primary-domain-dns-record)
for this node during disaster recovery procedure you may need to [block
all the writes to this node](planned_failover.md#prevent-updates-to-the-primary-node)
during this procedure.
1. [Setup database replication][database-replication]. Note that in this
case, **primary** node refers to the current **primary** node, and **secondary** node refers to the
former **primary** node.
If you have lost your original **primary** node, follow the
[setup instructions][setup-geo] to set up a new **secondary** node.
## Promote the **secondary** node to **primary** node
When the initial replication is complete and the **primary** node and **secondary** node are
closely in sync, you can do a [planned failover].
## Restore the **secondary** node
If your objective is to have two nodes again, you need to bring your **secondary**
node back online as well by repeating the first step
([configure the former **primary** node to be a **secondary** node](#configure-the-former-primary-node-to-be-a-secondary-node))
for the **secondary** node.
[setup-geo]: ../replication/index.md#setup-instructions
[database-replication]: ../replication/database.md
[disaster-recovery-disable-primary]: index.md#step-2-permanently-disable-the-primary-node
[planned failover]: planned_failover.md
|
