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operations are mapped directly onto the array APIs using a LUN per VDI representation. This includes activating
the data path on demand such as when a VM is started or migrated to another host.
Managed NetApp LUNs are accessible using the NetApp SR driver type, and are hosted on a Network Appliance
device running a version of Ontap 7.0 or greater. LUNs are allocated and mapped dynamically to the host using
the XenServer host management framework.
EqualLogic storage is accessible using the EqualLogic SR driver type, and is hosted on an EqualLogic storage array
running a firmware version of 4.0 or greater. LUNs are allocated and mapped dynamically to the host using the
XenServer host management framework.
For further information on StorageLink supported array systems and the various capabilities in each case, please
refer to the StorageLink documentation directly.
Storage Repository Types
The storage repository types supported in XenServer are provided by plugins in the control domain; these
can be examined and plugins supported third parties can be added to the /opt/xensource/sm directory.
Modification of these files is unsupported, but visibility of these files may be valuable to developers and power
users. New storage manager plugins placed in this directory are automatically detected by XenServer. Use the
sm-list command (see the section called “Storage Manager Commands”) to list the available SR types.
New storage repositories are created using the New Storage wizard in XenCenter. The wizard guides you through
the various probing and configuration steps. Alternatively, use the sr-create command. This command creates
a new SR on the storage substrate (potentially destroying any existing data), and creates the SR API object
and a corresponding PBD record, enabling VMs to use the storage. On successful creation of the SR, the PBD
is automatically plugged. If the SR shared=true flag is set, a PBD record is created and plugged for every
XenServer Host in the resource pool.
All XenServer SR types support VDI resize, fast cloning and snapshot. SRs based on the LVM SR type (local, iSCSI,
or HBA) provide thin provisioning for snapshot and hidden parent nodes. The other SR types support full thin
provisioning, including for virtual disks that are active.
Note:
Automatic LVM metadata archiving is disabled by default. This does not prevent metadata
recovery for LVM groups.
Warning:
When VHD VDIs are not attached, for example in the case of a VDI snapshot, they are stored
by default thinly-provisioned. Because of this it is imperative to ensure that there is sufficient
disk-space available for the VDI to become thickly provisioned when attempting to attach it.
VDI clones, however, are thickly-provisioned.
The maximum supported VDI sizes are:
Storage type Maximum VDI size
EXT3 2TB
LVM 2TB
NetApp 2TB
EqualLogic 15TB
ONTAP(NetApp) 12TB

Local LVM

The Local LVM type presents disks within a locally-attached Volume Group.