TOPIC ---------------------------------------------
I am trying determine the life span of a tape cartridge. The article says
"5,000 passes". Can you give me the suggested usage limits for a tape
cartridge? How many backups is that? How many times does the tape pass
through the drive during a backup?
DISCUSSION ---------------------------------------------
The tape cartridge life span can be greatly influenced by the environment
you store and use them in, and by whether you back up the tapes by Volume
or by File.
If you are backing up tapes by volume, your cartridge can last for a few
thousand backups. This estimate is not based on any controlled study, but
on the assumption that during a Volume backup, after the initial tensioning
of the tape, the drive generally records information on the tape from the
beginning to wherever it stops once it has completed transferring all of
the data. This is usually in one or two continuous passes. Incidentally,
the noise the drive makes when performing a Volume backup, changes in
pitch, and variance of the volume is not from the drive stopping the tape,
rewinding it, and proceeding forward--it is the drive switching tracks.
Backing up onto the tapes by File is much more stressful on the tape. The
drive may have to reverse direction of the tape many times to put the files
down sequentially on the tape, especially when the files are fractured on
the drive. We are unable to predict the longevity of a tape used for file
backups because of the great variance in the quantity of files backed up at
any time, the differences in sizes, and the degree to which they are
fractured. However, prudence should dictate practice when archiving data.
The operating environment also influences the tape life. Prior to using
the cartridge, let it acclimate to your operating environment for
eight hours or for the amount of time it has been exposed to dissimilar
conditions--whichever is less. Recommended operating environment:
Temperature 41 to 113 degrees F (5 to 45 degrees C)
Relative Humidity 20 to 80% noncondensing
Maximum Wet Bulb Temperature 79 degrees F (26 degrees C)
Tapes should be stored out of direct sunlight and not be exposed to
high temperatures.