About Proxied Volumes

Proxied Volumes, an optional licensed feature, enables many of the SANsymphony software advanced services to operate on top of pre-formatted volumes already in use before SANsymphony software was introduced into the configuration, without modifying the structure of existing data and with minimal disruption to current operations. Proxied Volumes are most often used as a temporary measure to migrate data from existing storage to a new architecture or to accelerate a deployment to more quickly receive the benefits of SANsymphony features. Proxied volumes require a file system of some kind and support all kinds of disk formats, such as Windows, Unix, AIX, and so on.

Some important functions allowed by the Proxied Volumes feature include performance enhancement through caching, replication over IP to any LUN (including non-SANsymphony LUNs), risk free deployment without requiring a backup/restore operation, and pass-through access to current disk contents while data is mirrored. A Proxied Volume can be brought into the SAN, mapped through the storage server, gaining all the capabilities of mirroring, replication, snapshot, etc. without requiring a backup/restore operation.

SANsymphony software treats Proxied Volumes differently from non-proxied virtual volumes:

  • SANsymphony software assumes that the volume is an existing disk that was previously formatted and partitioned by a host.

  • SANsymphony software assumes that the volume includes that host’s file system and live data exists on the volume.

The DataCore Disk Manager tool is the interface you will use to configure volumes as Proxied Volumes.  The DataCore Disk Manager tool allows you to place the storage server in Proxy Mode in order to configure individual volumes as Proxied Volumes.  While all logical volumes (non-proxy volumes) managed by SANsymphony software are automatically assigned a SANsymphony volume label, Proxied Volumes are not automatically tagged with this label.  Thus, a storage server running in Proxy Mode can discover these volumes and serve them to an application server without altering the live data on the volumes.

 

WARNING: It is crucial to enable Proxy Mode on the storage server before attaching the original host volumes to the storage server.  If the storage server is not in Proxy Mode, it will discover the original host volumes and write data to the disk, possibly corrupting the file system and/or data. If data is written to the disk, the original partition table would be damaged, rendering the disk unreadable by the host. Thus, when you configure a volume as a Proxied Volume, SANsymphony software sees the disk simply as a sequence of disk blocks and does not try to impose its own format on the device.  

 

While SANsymphony software supports standard SCSI disk commands (open, read, write, etc.), it does not process proprietary extended SCSI commands for Proxied Volumes.

Proxy mode is not supported for dual path volumes, as these volumes are visible from more than one source.

 

Related Topics:

Preparing Disks to be Proxied Volumes

Enabling/Disabling Proxy Mode

Identifying/Creating Proxied Volumes

Deleting Proxied Volumes

About Proxied Volumes