User Guide Part 2

26 7signal solution 139
7signal Solutions, Inc., 526 S. Main Street, Akron, Ohio 44311, USA, 855-763-9526, [e-mail], www.7signal.com
7signal Sapphire Carat User Guide Release 5.0
There is no need for purging in case of circular logging. The default logging method in 7signal
Sapphire is 'circular logging'.
Infinite archive logging
There is one secure way of purging the log files in the infinite archive directory. Offline backup
has to be done and this comes with price of the 7signal Sapphire halt. Offline backup provides
one single and unique point-in-time to be restored later. Once the offline backup exists, the
log files in the infinite archive directory become obsolete and may be removed.
The other option comes with no warranty whatsoever. The option is to keep 7signal Sapphire
running and to delete log files in the infinite archive directory. To understand what files are
likely to be unused, the active log files has to be followed to see the time to fill up a single log
file and then deduce what infinite archive files might be available for deleting . If one chooses
this option, setting the safety margins reasonably high is advisable.
In case there is both a system crash and a log file has been deleted too early, the
recovery shall never be able to finish. In this case, the only consistent system
stage is available at offline backup time.
The automated reporting lessens the impact of possible data loss if used in detail
and frequently. However, possibility to measurement drill-in analysis is lost as
well as any change in the network topology and other management information.
The infinite archival logging is provided in order to support online backups (see below) but it
should also be seen as a method to make system run longer automatically without user
interruption. However, the system has to be maintained and administered. It is outside of the
scope of this document to fit 7signal Sapphire to IT processes of all organizations but offline
backups with planned system halts are highly recommended.
26.2.3 Backup method options
Default state (not recommemded)
Essentially the 7signal Sapphire system default state is not a backup system at all but it is
based on the underlying database management system's robustness, fault tolerance and basic
level recovery options. In case of a permanent disk failure the data is lost. By installing the
databases on RAID disks lessens the risk further.
On default state the 7signal Sapphire relies on the database management system (IBM DB2)
logging. The assumptions are that the management information (Eye, access point and target
network) changes are not continuous but rather sporadic. The measurements are continuous
but losing few of the most recent samples is a risk that can be tolerated. Typical starting point
for analysis is one week of measurements and in case of sudden system down one would lose
the data until the system is fixed. And in case of system down it is expected that all the efforts
shall be there to bring 7signal Sapphire and other systems online again. There shall be no
special snapshots where to start operations again. It is possible to resume a state before the
interrupt, possibly the system is operational with no special effort at all.