Red Hat NETSCAPE MANAGEMENT SYSTEM 4.5 User Manual download pdf (Page 142)

Running VMware ESX Server

142

www.vmware.com

machines in the event of a full system loss or data loss due to failure of unprotected

disks.

However, these full-image backups do not permit you to restore individual files. You

must restore the entire disk image and any associated logs, then power on a virtual

machine with these drives connected to retrieve specific data.

The next section describes how to ensure data integrity when backing up virtual

machines from the physical computer or the console operating system.

Providing Optimum Data Integrity In Virtual Machine Backups Without

Downtime

You can use the Perl API included with ESX Server 1.5 in conjunction with backup

products to provide snapshots, or stable disk or redo log images. The appropriate

functions can be called from within many backup products in order to establish a safe

basis for backing up images or logs. You may use this approach with any disk mode —

persistent, undoable, nonpersistent or append.

To add a new redo log to a disk image while a virtual machine is running, a Perl

program would use a call of the format:

$vm->add_redo( $disk )

Once this call completes, new writes go into the new log file, making the underlying

disk image or redo log a stable, read-only file that you can copy to another location on

disk, directly to tape, or to another network location.

When you finish copying the files, you can commit the changes in the new log to the

original disk or redo log:

$vm->commit( $disk, $level, $freeze, $wait )

For incremental disk-level backups, add a redo log on top of the current log, back up

the underlying log and commit the new log. You can apply the most recent day’s

saved redo log to the full backup’s complete disk image.

For additional information on the Perl API, see the VMware Perl API documentation at

www.vmware.com/support/developer/perl-API/doc/.

Using Hardware or Software Disk Snapshots

You may choose to use the snapshot capabilities offered by your disk subsystem, file

system or volume manager to provide stable copies of disk images. As with physical

servers, consider using some level of application integration so you can be sure your

backups have the desired level of data integrity.

1 2 ... 137 138 139 140 141 142 143 144 145 146 147 ... 285 286

No comments

Red Hat NETSCAPE MANAGEMENT SYSTEM 4.5 User Manual Page 142