Every virtual machine uses a virtual disk — an image of the hard drive connected to it. Virtual disks are stored in a local or network storage. This article describes how to create a new storage. For more information please refer to the articles Virtual disk storage, Local storages, Network storages.

We recommend that you create the main virtual disk for operating systems and storage of less important data in a local storage. Keep more important data on the virtual disk in the network storage.

All cluster nodes in VMmanager must have the same sets of storages. When a new storage is added, the control panel adds it to all cluster nodes automatically if the network storage is used, or creates a storage on all cluster nodes if the local storage is utilized. The default storage template type is the "File system" named "File".

Complete the following steps to create a new storage:

  1. Go to Cluster settings → Storage templates → Add.
  2. Enter the storage Name.
  3. Select the storage Type:
    • File system — enter the path to the Directory on the cluster node where VM disk images will be kept and select a Disk format;
    • LVM;
    • Network LVM;
    • iSCSI — in the Network storage field enter the storage IP address or hostname; enter the Public key to access the storage through SSH, enable the option I have root password and enter root user password;
    • RBD — in the Network storage field enter the storage IP address or hostname; enter the Public key to access the storage through SSH, enable the option I have root password, and enter root user password;

    • GlusterFS — in the Network storage field enter the storage IP address or hostname; enter the path to the Directory on the cluster node where VM disk images will be kept and select a Disk format;

      Note.

      GlusterFS can be connected on the VMmanager cluster only on CentOS 7.

    • NFS — in the Network storage field enter the storage IP address or hostname; enter the path to the Directory on the network storage where VM disk images will be kept; enter the path to the Directory on the cluster node to mount the storage to; select a Disk format.
  4. Set the storage size for system needs
    1. Select the Units of measure: percent, MiB or GiB.
    2. Enter the Reserved amount.
  5. Select the A|O mode — asynchronous input-output mode:
    • default — "native";
    • threads — we recommend using it for file storages.
  6. Select the Caching type. It is used for virtual machines which disks are located in the storage. If you select "by default" in the A|O mode field set "none" or "directsync" as the caching type:
    • default — writeback;
    • none — caching is disabled;
    • writethrough — data is written to the cache and the backing store location at the same time;
    • writeback — data is written to the cache and then I/O completion is confirmed. The data is then typically also written to the backing store in the background but the completion confirmation is not blocked on that.;
    • directsync — the child system uses writethrough, the host doesn't use caching. Every write operation performs fsync. Make sure the QEMU version supports this caching type;
    • unsafe — the data is cached by the hypervisor and data synchronization requests from the quest machine are ignored. There is a high probability to lose your data.
  7.  Enter additional information in the Description field. It is displayed in the list of storage templates → the Status column.
  8. Click on Ok.