$ISA is an environment variable that allows 32- and 64-bit libraries to run together.
On Solaris 32-bit machines, $ISA is replaced by an empty string, while on 64-bit machines, it is replaced by the string “sparcv9”.
To use both 32- and 64-bit servers, place the 32-bit PAM module in a directory, and place the 64-bit version in a subdirectory of this directory.
The entry in pam.conf should look similar to:
$ ls /usr/lib/security/pam_sec.so.1 pam_sec.so.1 -> /SYBASE/pam_whatever_32bits.so.1 $ ls /usr/lib/security/sparcv9/pam_sec.so.1 pam_sec.so.1 -> /SYBASE/pam_sec_64bits.so.1 ase auth required /usr/lib/security/$ISA/pam_sec.so.1
$ISA is the only variable allowed in pam.conf.