IBM 000-8697 User Manual

IBM Informix OnLine Database Server Administrator’s Guide

The host machine where the tape device is attached must permit user
informix

 to run a

UNIX

 shell from your machine without requiring a

password. If your machine does not appear in the hosts.equiv file of the
other host machine, then it must appear in the .rhosts file in the home
directory of 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 as

LTAPESIZE

. If you need to change these values, you can do so

at the same time that you change the value of

LTAPEDEV

.

Specify

LTAPEBLK

 as the largest block size permitted by your tape device.

Specify

LTAPESIZE

as the maximum amount of data that should be written to

this tape.

If you are changing the value of

LTAPEDEV

 from a pathname to /dev/null,

take OnLine offline before you execute this change. If you make the change
while OnLine 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
interrupt processing because OnLine stops if it finds that the next logical log
file (in sequence) is not free.

As soon 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 within

DB-M

onitor, select the Logical-Logs menu, Tape-Param-

eters option to change the value of

LTAPEDEV

.

DB-M

onitor displays

the current value.

Enter the new full pathname value for the logical log tape device in
the

Log Tape Device

 field.

Enter new values in the device

Block Size

and

Tape Size

fields, if

appropriate.