Installation and Initial Configuration 1-47
OnLine Disk Space Allocation
The logs contain critical information and should be located in mirrored
dbspaces, despite the fact that their high level of activity makes it costly (in
terms of performance) to do so.
Compare the total amount of dbspace disk space (exclude blobspaces) that
you intend to allocate to OnLine with the amount of space dedicated to
OnLinelogging (physical log size plus total space allocated for the logical log
files). Ideally, logging space should be about 20 percent of total dbspace.
Adjust your worksheet values, if necessary.
(Youshould have values entered for all parameters on the worksheet except
forROOTOFFSET and MIRROROFFSET. Guidelines for these parameters are
described as part of the next topic.)
How to Allocate Disk Space
This section provides instructions for allocating raw disk space or cooked
files.

Cooked File Space

Toallocate cooked file space, concatenate null to a pathname that represents
one chunk of cooked file space. The cooked disk space file should have
permissionsset to 660 (rw-rw----). Group and owner must be set to informix.
# become root
su root
password:
# create file for the cooked device
cat /dev/null > chunk_pathname
# establish correct ownership
chown informix chunk_pathname
chgrp informix chunk_pathname
chmod 660 chunk_pathname
exit
Ifyou are planning to locate your root dbspace in a cooked file, verify that the
pathnamefor the cooked file is the value of ROOTPATHon your configuration
worksheet.