User`s guide

Routine maintenance 18-7
Backing up the system
Standard 1.0 System Administration Guide January 1998
Backing up the system
Introduction
If a disk drive fails, the system can be restored to a working
state by copying the data back from tape onto a replacement
disk. Backup copies of the system data are fundamental to
restoring the system with as little disruption and data loss as
possible.
Backups to tape
All Meridian Mail systems have a tape drive capable of reading
and writing industry-standard quarter-inch data cartridges
(QIC). Backups to tape can be either full or partial. You can
also selectively back up users or services to tape, or both.
Backups to disk
If the Disk-to-Disk Backup feature is installed, you can copy
data from one disk to another. This allows you to recover data if
a disk fails.
Backups to disk can be done frequently, with relatively little
effort, and reduce the need for frequent and time-consuming
backups to tape. However, disk-to-disk backups do not
completely eliminate the need for tape backups.
Storage impact
Disk-to-disk backup reduces the voice message storage
somewhat and sets aside some of the disk space for backup
copies.
Scheduling a backup
Schedule backups for a time when your system is relatively
quiet or outside the regular business hours for your
organization. Do not back up the system if it is operating above
50% of the rated capacity or between the hours of
1:00 a.m. and 5:00 a.m., since important system audits take
place during these hours. These audits are activated
automatically at the same time every day and ensure the
continued operation of your system. Do not schedule a backup
if more than one tape is required for it unless you are going to
be available to switch tapes when you are prompted to do so.