よくある質問
よくある質問: Tsukaeru Cloud
Difference between containers (CT) and virtual machines (VM)
投稿者: Wiktor Klonowski on 13 July 2016 05:09 PM

With Tsukaeru Cloud, you can choose between two types of servers: containers (CT) and virtual machines (VM). Below, there are listed pros and cons of each system.

 

*With Linux, if used simply for web or mail server, we recommend container type.

*In case of Windows, only virtual machine type is available.

 

■ Container (CT)

Pros:

  ・Lower resource overhead (= higher performance)

  ・CPU, memory and disk size can be changed online

  ・When creating, new system can be installed from preset templates
   Because standard applications are just linked to the machine,
   both memory as well as available disc space can be utilized more efficiently

Cons:

  ・No access to the kernel (cannot change any kernel parameters, etc.)

  ・Cannot load modules not included in the running kernel

 

■ Virtual Machine (Hypervisor, VM)

Pros:

  ・Access to the kernel level (changing setting, customization, etc.)

Cons:

  ・Because of running behind virtual machine emulator,
   there is higher overhead on resources, when compared to CT

  ・Because all relevant OS and application data is kept in private space of each machine,
   the amount of both disc space and RAM available for user is lower compared to CT

  ・Because of virtualization software updates, it may be necssary to stop VMs for a short period of time

※ Auto scale feature is not available for VMs

Example VM's use cases:

  kernel mode load balancer (LVS)

  using modules not loaded to the kernel be default (special iptables, etc.)