Restore notes and restrictions on Linux
This topic relates to the restore of files from a NetBackup backup of a VMware virtual machine that runs Linux.
Before you begin the restore, note the following:
Cross-platform restore of individual files is not supported. You can restore Linux files to supported Linux guest operating systems but not to Windows.
To migrate an ext2 or ext3 file system to ext4, note: Make sure to follow the instructions under "Converting an ext3 file system to ext4" on the following page of the Ext4 wiki:
https://ext4.wiki.kernel.org/index.php/UpgradeToExt4
If you do not follow these instructions, data in a newly created ext4 file is not promptly flushed from memory to disk. As a result, NetBackup cannot back up the data of recently created files in the ext4 file system. (The NetBackup snapshot captures the file as zero length.)
As a workaround for the file systems that were not correctly migrated, do one of the following:
Run the Linux sync command on the ext4 file system before starting each backup.
Make sure that snapshot quiesce is enabled in the Linux guest OS. Contact your operating system vendor and VMware for additional information.
For Linux virtual machines, NetBackup cannot restore individual files from software RAID volumes. The files are restored when you restore the entire virtual machine.
The Linux ext4 file system includes a persistent pre-allocation feature, to guarantee disk space for files without padding the allocated space with zeros. When NetBackup restores a pre-allocated file (to any supported ext file system), the file loses its preallocation and is restored as a sparse file. The restored sparse file is only as large as the last byte that was written to the original file. Note also that subsequent writes to the sparse file may be non-contiguous.
NetBackup supports backup and restore of Linux LVM2 volumes, including individual file restore from an LVM2 volume. Note however that NetBackup does not support individual file restore from a snapshot that was created by means of the snapshot feature in LVM2. If an LVM2 snapshot exists at the time of the backup, the data in the snapshot is captured in the backup. The data can be restored along with the rest of the virtual machine data when you recover the entire virtual machine.
NetBackup supports backup of Linux FIFO files and socket files. NetBackup does not support restoring FIFO files and socket files individually. FIFO files and socket files can be restored along with the rest of the virtual machine data when you recover the entire virtual machine.
For Linux virtual machines, the ext2, ext3, and ext4 file systems are supported for individual file restore. If a partition uses some other file system, the backup succeeds but files in that partition cannot be individually restored. To allow NetBackup to present mount points for restore in the Backup, Archive, and Restore interface, note: The "/" (root) partition must be formatted with ext2, ext3, or ext4.
See Mount points not available when restoring files from a Linux virtual machine.
When you restore Linux files individually to an NFS-shared device on a Linux virtual machine, NetBackup can only restore the file data and attributes. The extended attributes cannot be restored to NFS-shared devices.
For a virtual machine that is running a Linux guest operating system: When you restore a virtual machine, the ESX server may assign the virtual machine a new (virtual) MAC address. After you restart the virtual machine, you may have to configure its MAC address. For instance, the original MAC address of the virtual machine may be in a configuration file that has to be updated.
Refer to your VMware documentation for more details.
For Linux, additional notes apply.