# Management Plane Upgrade Fails with "Connection timed out" Error.

## Problem:

* Management Upgrade failed with below mentioned error in the `airctl-logs/pf9deploy-prepare-restore.log` file.

{% tabs %}
{% tab title="Error" %}

```javascript
2023-06-13T05:36:25.811Z info INFO:pf9deploy.server.util.shell:| fatal: [airctl-1.pf9.localnet]: UNREACHABLE! => {"changed": false, "msg": "Connection timed out.", "unreachable": true}
 2023-06-13T05:36:25.811Z info INFO:pf9deploy.server.util.shell:| to retry, use: --limit @/ansible-stack/mysql-configure-only.retry
 2023-06-13T05:36:25.811Z info INFO:pf9deploy.server.util.shell:| 
 2023-06-13T05:36:25.811Z info INFO:pf9deploy.server.util.shell:| PLAY RECAP *********************************************************************
 2023-06-13T05:36:25.811Z info INFO:pf9deploy.server.util.shell:| airctl-1.pf9.localnet      : ok=0    changed=0    unreachable=1    failed=0
```

{% endtab %}
{% endtabs %}

## Environment:

* Platform9 Edge Cloud - v5.3 and Higher
* Airctl

## Troubleshooting:

* Try to ssh to the deployment host using FQDN and confirm if it fails with `Operation not permitted` error.

{% tabs %}
{% tab title="SSH error" %}

```javascript
$ ssh airctl-1.pf9.localnet
Warning: Permanently added 'airctl-1.pf9.localnet,10.10.13.133' (ECDSA) to the list of known hosts.
-bash: ulimit: open files: cannot modify limit: Operation not permitted
```

{% endtab %}
{% endtabs %}

## Resolution:

* Please perform below mentioned changes on the Deployment Host.
* Add below mentioned entries in file `/etc/security/limits.conf`

{% tabs %}
{% tab title="Javascript" %}

```javascript
* soft     nproc          1048576
* hard     nproc          1048576
* soft     nofile         1048576
* hard     nofile         1048576
root soft     nproc          1048576
root hard     nproc          1048576
root soft     nofile         1048576
root hard     nofile         1048576
```

{% endtab %}
{% endtabs %}

* Add below mentioned line in `/etc/pam.d/sshd` file.

{% tabs %}
{% tab title="Javascript" %}

```javascript
session    required   pam_limits.so
```

{% endtab %}
{% endtabs %}


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