What is the difference between a Linux virtual machine and a SmartMachine?

The main difference between the two is operating system. SmartMachines run SmartOS, which is a major fork of OpenSolaris. Linux virtual machines run one of four popular Linux distributions: CentOS, Debian, Fedora, or Ubuntu.

What is my host name?

To find your host name, run the hostname command from the terminal.

Are Linux virtual machines pre-configured?

Linux virtual machines come preconfigured with a very small number of tools, such as Perl, Python, bash, vim, diff, and so on. To install additional software, use the package tool for your Linux distribution:

• Debian and Ubuntu: use apt
• CentOS: use yum

What is my IP address?

The following one-line script displays the IP address of your virtual machine:

Why do I have two drives?

Your Linux virtual machine includes two mounted disks:

• The OS disk /dev/vda
• Your data disk /dev/vdb

All OS disks are the same size and not intended for data storage. The disk you use for storing data is /dev/vdb and varies in capacity based on the size of your virtual machine.

If you run out of space on /dev/vda you will need to do one of the following:

• Move the directory from /dev/vdb and create a symbolic link on /dev/vda:
• Configure servers to store data on /dev/vdb.

For example, use /data/mysql as the directory to store MySQL logs and databases.

What is the best kernel to use with Linux virtual machines?

The default kernel that runs on all Joyent Linux VMs is a Linux 3.1 kernel that has been optimized for performance and stability.

Joyent highly recommends that you use the Joyent provided Linux kernels.

How do I add another Linux virtual machine?

To add another Linux machine, go to https://my.joyentcloud.com.

How do I login to my Linux virtual machine?

Prior to provisioning a Linux VM, ensure that you have uploaded a valid [SSH key|sharedEol:Generating an SSH Key] to your Cloud Management portal . Once provisioned, you can login as the root user using ssh. You will need to specify the public IP of the machine.

Once you log in, you may want to do the following:

• Change the root user password.
• Create an admin user account
• Disable SSH root access

Why is my memory usage high in top when I am not running many processes?

Linux will consume physical RAM and only release it when necessary.

If you run the command:

You will notice that most of the RAM that is cached is usable. You can alos check on available memory with:

The value listed for inact is RAM that is currently available. Here is a good article that explains this in greater detail:

http://chrisjohnston.org/ubuntu/why-on-linux-am-i-seeing-so-much-ram-usage

What Linux distribution am I running?

The /proc/version file contains information about the Linux distribution. If you use the command cat /proc/version, you will see one of the following:

Why are my SSH keys out of date on my virtual machine?

When a virtual machine is provisioned we take a snapshot of your SSH public keys and write this to a metadata api key which is used to populate your virtual machines /root/.ssh/authorized_keys file. If you delete this file it will repopulate this file on reboot with this cached metadata. It's best to manually maintain this file or use a software configuration management tool such as puppet or chef to do this for you.