VSA Backup Fails When You Use a Linux Proxy That Has Multiple SCSI Controllers

A backup for the Virtual Server Agent with VMware fails when using HotAdd transport with a VSA proxy that is running on Linux and that has multiple SCSI controllers. This is a known issue identified by VMware.

Symptoms

When you use a Linux VSA proxy that has multiple SCSI controllers to back up VMware VMs, a backup that uses HotAdd transport might fail. The following error appears in the vsbkp.log file:

Dispatch_VixDiskLib_Open() - VixDiskLib_Open failed Err=d You do not have access rights to this file CloseHostDiskhandlesOnFailure() - There are no handles to close. OpenHostDiskHandle() - Failed to open disk handle for [datastore_volume_path] OpenDisk() - Failed to open disk handle for disk [datastore_volume_path] host [hostname] Failed to Open Disk [datastore_volume_path]

The following error appears in the VixDiskLib.log file:

Mounting VM vm_name using transport hotadd failed : HotAdd ManagerLoop caught an exception.

Causes

When the Linux proxy has multiple SCSI controllers, HotAdd transport might not recognize VM disks correctly.

Resolution

To work around this issue, if the number of concurrent backup streams is less than the number of free slots in SCSI controller 0, do not add SCSI controllers to the proxy VM. For a Linux proxy that has multiple SCSI controllers, perform the following steps:

1. Verify that operating system disks are on SCSI controller 0 in numeric sequence.
2. Add SCSI controllers in numeric sequence.
3. Add SATA controller 0.
4. Verify that the proxy VM does not have a CD-ROM device.
5. Verify that there is no device on IDEO/1.
6. Verify that there is no disk or other device on the SATA controller.
7. Reboot the VM.

For more information, see the VMware KB article Best practice for Linux proxy VM configuration in HotAdd transport (67757).