SNAX/XF LU Network Services Manual

Creating New Configuration Tables
Using LUNS
097841 Tandem Computers Incorporated 2–3
Creating New
Configuration Tables
Within a command file, the SNAXUTL SELECTFILE command names the table source
file for a new SET or ESS table. Table source file names should be of the following
form:
$ vvvvvvv.sssssss.fffffff
fffffff can consist of from one through seven characters. SNAXUTL gives the
corresponding table object file the same name, but appends the letter O:
$ vvvvvvv.sssssss.fffffff O
Thus, if the SNAXUTL SELECTFILE command were to name a table source file
$SYSTEM.SNAX.ESSTAB1, the table object file would automatically be named
$SYSTEM.SNAX.ESSTAB1O.
Because SNAXUTL creates this file immediately upon creating the table source file,
you must make sure that SNAXUTL will not attempt to give it the name of a file that
already exists. Otherwise, an allocation failure occurs. To guard against this, Tandem
recommends that all LUNS files be placed in a separate subvolume.
Immediately after the SELECTFILE command, you must include a SNAXUTL
ALLOCATE command. When SNAXUTL is run, space is allocated for both source and
object files. The space reserved for each of these files is equal.
The ALLOCATE command allows you to specify an extent size, in pages, for any file
you allocate. The command syntax is:
ALLOCATE extent-size
extent-size specifies the number of pages that an individual extent contains. The
file system can automatically provide you with as many as 16 extents for any file you
allocate. Thus, were you to specify extent-size as 20 pages, your file could contain
a maximum of 320 pages (16 * 20 pages). Tandem recommends that you specify 10
pages. If you wish to calculate the extent size yourself, see “ALLOCATE Command”
in Appendix A.
When you create an ESS table, you must add a record for it to the SET table with the
SNAXUTL ADD SETESS command. See “Specifying the SET Table” in this section.