Air Cleaner User Manual

Unlike all other backup types, this type of backup contains no Logical Volume
Manager (LVM) information. Therefore, it is not possible to use this backup,
regardless of its contents, for recreating volume groups, logical volumes, and
filesystems. Using this backup option for backing up all files on the system (from
the / directory) cannot provide a backup that can be used to reinstall the system.
Some files and directories on the system, such as certain contents of the root (/)
and /usr filesystems, should never be restored from a backup, as this would
adversely affect the active system configuration and can cause either system errors
or a complete system failure. Use this command only to back up files and
directories that contain non-system-related information, such as user data,
application programs, and so on.
Using the -m option, you can also specify to back up only files that have been
modified within a certain number of days. This is useful for performing daily
backups. Be aware, however, that a day is considered exactly 24 hours. Therefore,
always back up at least every 24 hours when specifying the -m1 option. If, for
instance, your backups were performed 1/2 hour later today than yesterday,
neither today’s nor yesterday’s backup will contain any files changed within that
1/2 hour. It is a good idea to use -m2 each day to ensure that no files will be
skipped regardless of the time the backup is performed.
Always perform a backup of all files, regardless of date, before performing partial
backups using the -m option. If you later need to restore files or directories, restore
them from a full backup, and then restore each partial backup created after the full
backup.
The backup can also be performed as a “pull” backup to enable central
management of backups. The machine that “pulls” the backup is called the
“initiator,” while the machine that is backed up is called the “backup system.” The
machine that receives the backup data is called the “destination system.”
The initiator is the machine where the mkdirback command is issued. The backup
system is referenced in the command syntax by the -U “host” flag. The data
destination system is referenced by the -h “host flag”.
When only the -U “host” flag is specified, the -f “device” flag refers to a device on
the initiator system. In this case, the backup destination and the initiator are the
same system. This is known as a “two-way pull backup.”
When the -U “host” and -h “host” flags are specified, the -f “device” flag refers to
a device on the host specified by the -h “host” flag. In this case, the backup
destination and the initiator are different systems. This is known as a “three-way
pull backup.”
Remote Services must be configured, using the cfgremsvs command, on all of the
machines involved in the backup operation, the initiator, the backup system, and
the data destination machines. The backup destination machine must have the
Server Options of Remote Services configured to allow the backup system machine
to send its data to devices on the backup destination machine. You can do this
with the Add or Change Client Host Access to this Server option or the
cfgremaccess command.
A-30 IBM Tivoli Storage Manager for System Backup and Recovery: Installation and User’s Guide