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| <section id="hypervisor-support-for-primarystorage"> |
| <title>Hypervisor Support for Primary Storage</title> |
| <para>The following table shows storage options and parameters for different hypervisors.</para> |
| <informaltable> |
| <tgroup cols="5"> |
| <colspec colname="c1" colnum="1" colwidth="34%"/> |
| <colspec colname="c2" colnum="2" colwidth="16%"/> |
| <colspec colname="c3" colnum="3" colwidth="16%"/> |
| <colspec colname="c4" colnum="4" colwidth="17%"/> |
| <colspec colname="c5" colnum="5" colwidth="17%"/> |
| <thead> |
| <row> |
| <entry/> |
| <entry><para>VMware vSphere</para></entry> |
| <entry><para>Citrix XenServer</para></entry> |
| <entry><para>KVM</para></entry> |
| <entry><para>Hyper-V</para></entry> |
| </row> |
| </thead> |
| <tbody> |
| <row> |
| <entry><para><emphasis role="bold"><emphasis role="bold">Format for Disks, Templates, and |
| Snapshots</emphasis></emphasis></para></entry> |
| <entry><para>VMDK</para></entry> |
| <entry><para>VHD</para></entry> |
| <entry><para>QCOW2</para></entry> |
| <entry><para>VHD</para> |
| <para>Snapshots are not supported.</para></entry> |
| </row> |
| <row> |
| <entry><para><emphasis role="bold">iSCSI support</emphasis></para></entry> |
| <entry><para>VMFS</para></entry> |
| <entry><para>Clustered LVM</para></entry> |
| <entry><para>Yes, via Shared Mountpoint</para></entry> |
| <entry><para>No</para></entry> |
| </row> |
| <row> |
| <entry><para><emphasis role="bold">Fiber Channel support</emphasis></para></entry> |
| <entry><para>VMFS</para></entry> |
| <entry><para>Yes, via Existing SR</para></entry> |
| <entry><para>Yes, via Shared Mountpoint</para></entry> |
| <entry><para>No</para></entry> |
| </row> |
| <row> |
| <entry><para><emphasis role="bold">NFS support</emphasis></para></entry> |
| <entry><para>Y</para></entry> |
| <entry><para>Y</para></entry> |
| <entry><para>Y</para></entry> |
| <entry><para>No</para></entry> |
| </row> |
| <row> |
| <entry><para><emphasis role="bold">Local storage support</emphasis></para></entry> |
| <entry><para>Y</para></entry> |
| <entry><para>Y</para></entry> |
| <entry><para>Y</para></entry> |
| <entry><para>Y</para></entry> |
| </row> |
| <row> |
| <entry><para><emphasis role="bold">Storage over-provisioning</emphasis></para></entry> |
| <entry><para>NFS and iSCSI</para></entry> |
| <entry><para>NFS</para></entry> |
| <entry><para>NFS</para></entry> |
| <entry><para>No</para></entry> |
| </row> |
| <row> |
| <entry><para><emphasis role="bold">SMB/CIFS</emphasis></para></entry> |
| <entry><para>No</para></entry> |
| <entry><para>No</para></entry> |
| <entry><para>No</para></entry> |
| <entry><para>Yes</para></entry> |
| </row> |
| </tbody> |
| </tgroup> |
| </informaltable> |
| <para>XenServer uses a clustered LVM system to store VM images on iSCSI and Fiber Channel volumes |
| and does not support over-provisioning in the hypervisor. The storage server itself, however, |
| can support thin-provisioning. As a result the &PRODUCT; can still support storage |
| over-provisioning by running on thin-provisioned storage volumes.</para> |
| <para>KVM supports "Shared Mountpoint" storage. A shared mountpoint is a file system path local to |
| each server in a given cluster. The path must be the same across all Hosts in the cluster, for |
| example /mnt/primary1. This shared mountpoint is assumed to be a clustered filesystem such as |
| OCFS2. In this case the &PRODUCT; does not attempt to mount or unmount the storage as is done |
| with NFS. The &PRODUCT; requires that the administrator insure that the storage is |
| available</para> |
| <!-- <para>Oracle VM supports both iSCSI and NFS storage. When iSCSI is used with OVM, the &PRODUCT; administrator is responsible for setting up iSCSI on the host, including re-mounting the storage after the host recovers from a failure such as a network outage. With other hypervisors, &PRODUCT; takes care of mounting the iSCSI target on the host whenever it discovers a connection with an iSCSI server and unmounting the target when it discovers the connection is down.</para> --> |
| <para>With NFS storage, &PRODUCT; manages the overprovisioning. In this case the global |
| configuration parameter storage.overprovisioning.factor controls the degree of overprovisioning. |
| This is independent of hypervisor type.</para> |
| <para>Local storage is an option for primary storage for vSphere, XenServer, and KVM. When the |
| local disk option is enabled, a local disk storage pool is automatically created on each host. |
| To use local storage for the System Virtual Machines (such as the Virtual Router), set |
| system.vm.use.local.storage to true in global configuration.</para> |
| <para>&PRODUCT; supports multiple primary storage pools in a Cluster. For example, you could |
| provision 2 NFS servers in primary storage. Or you could provision 1 iSCSI LUN initially and |
| then add a second iSCSI LUN when the first approaches capacity.</para> |
| </section> |
