vm_proxy_fs

The vm_proxy_fs process creates and services the “read only” file system known as /export.

The /export file system (pronounced slash export) contains configured hypervisors and their export enabled virtual machines. Also when vmPRO folders are used to organize virtual machines, those folders will be visible in this file system.

This following screen shot of /export shows a hypervisor (tsvcenter2), a vmPRO folder (test), three VMs assigned to the test folder and the files for one of the VMs named ubuntu9:

Screenshot of /export

All files in /export filesystem directly corresponds to files in /vmfs/volumes except for the cfg and pancbt.vmdk files. These two files are added to the /export filesystem by vm_proxy_fs and provide additional functions. A cfg file is added to each VM’s directory in /export and provides configuration information about the VM. This information is used by the appliance when recovering the VM.

When CBT (Changed Block Tracking) is enabled for the VM by a user of the appliance, a pancbt file is added to a VM’s directory for each disk. This file represents the differential changes that occur to a VM’s disk.

The flat.vmdk file is the data file (disk) for a VM. A flat file exists for each virtual disk assigned to the VM in vSphere. The <vmname>.vmdk (ubuntu9.vmdk in the screen shot) is the ascii descriptor file for the flat file. And the vmx file is the configuration file for the VM. To properly protect this VM all of these files will need to be backed up for the initial backup and subsequent backup can be differential (pancbt) backup.

Typically, an open (read) operation of the data file (flat.vmdk) or the pancbt file will cause vm_proxy_fs to take a snapshot of the VM if this vmPRO appliance has not already created a snapshot for the VM and then open the same file in /vmfs/volumes filesystem managed by datastore_fs for reading. If the opened file is the pancbt file vm_proxy_fs will also perform a CBT query to the ESX server to gather extents of the disk that have changed since last full backup.

vm_proxy_fs also interacts with the controller to gather configuration information about VMs. In return it posts disk read statistics to the controller via http posts.

The /export filesystem is available to SmartMotion and integrated backup clients for direct access and exported for access to every backup application that supports network backup via CIFS and NFS.

Please note that only virtual machine images and configuration files are available in /export.

Troubleshooting

Setting the registry key appliance.debug.level to a small positive integer will enable general debug output, which increases in verbosity with a higher value. Setting the registry key appliance.cbt.debug to a positive integer enables debug output that is specific to the CBT feature. Note that setting these keys can result in significant log output.

vm_proxy_fs log entries are written to /var/log/vm_proxy_fs

Process Communication Flow:

Controller <==================>

Datastore_fs <===========> vm_proxy_fs =============> NFS/CIFS

================================================================

/vmfs/volumes ------------- /export -------------- NFS/CIFS\

What's Next?

files_fs >