Product Documentation

Storage Multipathing

Nov 20, 2012
Dynamic multipathing support is available for Fibre Channel and iSCSI storage repositories. By default, multipathing uses round robin mode load balancing, so both routes will have active traffic on them during normal operation. You enable and disable storage multipathing in XenCenter via the Multipathing tab on the server's Properties dialog.

Before you enable multipathing:

  • Verify that multiple targets are available on your storage server.
  • The server must be placed in Maintenance Mode; this ensures that any running virtual machines with virtual disks in the affected storage repository are migrated before the changes are made.
  • Multipathing must be configured on each host in the pool. All cabling and, in the case of iSCSI, subnet configurations must match for the corresponding NICs on each host. (For example, all NIC 3s must be configured to use the same subnet. See Configuring IP Addresses for more information.)

For more in-depth multipathing information, see the Configuring iSCSI Multipathing Support for XenServer guide and the XenServer Administrator's Guide.

To enable multipathing

  1. In the Resources pane, select the server and then put it into Maintenance Mode. There is a short delay while XenCenter migrates any active virtual machines and unplugs the existing storage; if the server is a pool master, it will be disconnected and may disappear from the Resources pane temporarily while a new pool master is assigned. When the server reappears in the Resources pane with the icon icon, continue to the next step.
  2. On the General tab, click Properties and then click on the Multipathing tab.
  3. To enable multipathing, select the Enable multipathing on this server check box. To disable multipathing, clear the check box.
  4. Click OK to apply the new setting and close the dialog box. There is a short delay while XenCenter saves the new storage configuration.
  5. Take the server back out of Maintenance Mode: select it in the Resources pane, right-click, and click Exit Maintenance Mode.