Hosting tasks

Rescale a server

Linode makes it easy to scale/resize a server (number of cores and GiB of RAM).

You must re-deploy the server to re-configure states that depend on total memory (grains.mem_total), like swap, Elasticsearch and PostgreSQL.

Rescale reserved space

When adding a new disk or increasing an existing disk over 100 GB, set reserved space to 1% (from 5%) if it is a root partition, and 0% otherwise. For example, to reduce /dev/md2, as root:

tune2fs -m 1 /dev/md2

If reducing an existing disk below 100 GB, restore reserved space to 5%. For example:

tune2fs -m 5 /dev/md2

Manager cloud services

Azure

Configure Azure portal

  1. Open the Directories + subscriptions settings

  2. Set Default subscription filter to “All subscriptions”

Configure Azure CLI

  1. Install the Azure CLI

  2. Log in to Azure:

    az login

  3. Set the default subscription:

    az account set --subscription 4e98b5b1-1619-44be-a38e-90cdb8e4bc95

  4. Set the default resource group:

    az configure --defaults group=default

See also

Commands

Recover a server

If a server becomes inaccessible, including via SSH, log into the hosting provider and:

  1. Reboot the server. This often restores access, as unsaved changes to firewall rules are reset, system resources are freed, and running processes are restarted.

  2. Use a recovery system to restore access if the server remains inaccessible.

Lish (Linode Shell) provides console access to our Linode instances, similar to connecting via SSH.

  1. Log into Linode

  2. Select the server you want to access

  3. Click the Launch LISH Console link

  4. Login as root, using the password from OCP’s LastPass account

Hetzner Cloud offers two recovery methods.

  1. Log into Hetzner Cloud Console

  2. Click the Default project

  3. Select the server you want to access

  4. Click the Actions button

  5. Click the Console menu item

  1. Log into Hetzner Cloud Console

  2. Click the Default project

  3. Select the server you want to access

  4. Activate the rescue system:

    1. Click the Rescue tab

    2. Click the Enable rescue & power cycle button

    3. Set Choose a Rescue OS to linux64

    4. Select your key for SSH key (if missing, add it via the project’s Security menu item)

    5. Click the Enable rescue button

  5. Connect to the server as the root user using SSH

Hetzner Dedicated offers two recovery methods.

The Hetzner Rescue System boots the server using a temporary recovery image, from which we can mount the server drives to fix issues.

  1. Log into Hetzner Robot

  2. Select the server you want to access

  3. Activate the rescue system:

    1. Click the Rescue tab

    2. Set Operating system to Linux

    3. Set Architecture to 64 bit

    4. Select your key for Public key (if missing, add it in Key management)

    5. Click the Activate rescue system button

  4. Reboot the server:

    1. Click the Reset tab

    2. Set Reset type to Press power button of server or Send CTRL+ALT+DEL to the server

    3. Click the Send button

    It takes some time to process the instruction. If nothing happens after 5 minutes, try again using Execute an automatic hardware reset.

  5. Connect to the server as the root user using SSH

  6. Mount the drive(s):

    mount /dev/md/2 /mnt

  7. Optionally, chroot into the operating system:

    chroot-prepare /mnt
chroot /mnt

Hetzner technicians attach a remote console (KVM Console) to a dedicated server. This option is slow to set up, but might be required if the issue is with the network, firewall or SSH configuration.

  1. Log into Azure

  2. Click the Virtual machines icon

  3. Select the server you want to access

  4. Click the Connect menu item

  5. Expand the More ways to connect detail

  6. Click the Go to serial console button

  7. Login as ocpadmin, using the password from OCP’s LastPass account

See also

Azure Serial Console