3-20 IBM Informix OnLine Database Server Administrator’s Guide
Change Pathname of Logical Log Tape Device
The host machine where the tape device is attached must permit user
informix to run aUNIX shell from your machine without requiring a
password. If your machine does not appear in thehosts.equiv file of the
other host machine, then it must appear in the.rhosts file in the home
directoryof the informix login. If you are backing up logical log files as root,
the machine name must appear in the.rhosts file for root on the other host
machine.
Verify that the block size and the tape size are correct for the new device.
Block size for the logical log tape device is specified as LTAPEBLK. Tape size
is specified asLTAPESIZE. If you need to change these values, you can do so
at the same time that you change the value ofLTAPEDEV.
Specify LTAPEBLK as the largest block size permitted by your tape device.
SpecifyLTAPESIZE as the maximum amount of data that should be written to
this tape.
If you are changing the value ofLTAPEDEV from a pathname to /dev/null,
take OnLine offline before you execute this change. If you make the change
whileOnLine is in either quiescent or online mode, you can create a situation
in which one or more log files are backed up, but never freed. This can
interruptprocessing because OnLine stops if it finds that the next logical log
file (in sequence) is not free.
Assoon as you make the change, you are only able to restore your system up
to the point of your most recent archive and any previously backed-up
logical logs. You cannot restore work done since then.
From DB-Monitor
1. Fromwithin DB-Monitor, select the Logical-Logs menu, Tape-Param-
eters option to change the value of LTAPEDEV.DB-Monitor displays
the current value.
2. Enter the new full pathname value for the logical log tape device in
the Log Tape Device field.
3. Enternew values in the device Block Size and Tape Size fields, if
appropriate.