Notes on Linux virtual machines
The following notes apply to virtual machines with Linux guest operating systems:
Windows Hyper-V provides no mechanism for quiescing file system activity on Linux virtual machines.
As a result, NetBackup has no way to guarantee that data in the file system is in a consistent state when the snapshot occurs. If data has not been flushed to disk before the snapshot is created, that data is not included in the snapshot.
To guarantee that Linux files are consistent at the time of backup, turn off the virtual machine before backing it up. When the virtual machine is turned off, data buffers are flushed to disk and the file system is consistent.
For a description of file system quiesce, see the NetBackup Snapshot Client Administrator's Guide.
Unmounted LVM2 volumes must start with /dev
If the path of an unmounted LVM2 volume does not start with /dev, the backup of the virtual machine fails. Note: The path of the volume is set with the dir parameter on the LVM volume configuration file. An example of this configuration file is
/etc/lvm/lvm.conf.For Linux files or directories, NetBackup for Hyper-V has the same path name restriction as NetBackup on a Linux physical host. Files or directories with path names longer than 1023 characters cannot be individually backed up or restored. Such files can be restored when you restore the entire virtual machine from a full virtual machine backup.
For more information on the files that NetBackup does not back up, refer to the topic on excluding files from backups in the NetBackup Administrator's Guide for UNIX and Linux, Vol I.
The NetBackup policy's option is not supported for the disks inside a Linux guest OS that are configured as follows:
The disks are divided into logical volumes by means of the Linux Logical Volume Manager (LVM), and
The LVM volumes were created with thin-provisioning.
More information is available on the restore of Hyper-V virtual machines.