如何永久修改SUSE Linux Enterprise Server 10.4上打开文件的ulimit？

SERVER:/etc # ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
file size               (blocks, -f) unlimited
pending signals                 (-i) 96069
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 96069
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited
SERVER:/etc # 

如何将root用户的限制永久设置为1024？如何全局设置ulimit？更改是否会立即生效？

ps：我已经用它搜索了一下，但是找不到可以永久设置的文件：

SERVER:/etc # grep -RiI ulimit * 2>/dev/null | egrep -v ":#|#ulimit"
init.d/boot.multipath:      ulimit -n $MAX_OPEN_FDS
init.d/multipathd:      ulimit -n $MAX_OPEN_FDS
rc.d/boot.multipath:        ulimit -n $MAX_OPEN_FDS
rc.d/multipathd:        ulimit -n $MAX_OPEN_FDS

和..：

SERVER:/etc # grep -RiI 'MAX_OPEN_FDS' * 2>/dev/null
init.d/boot.multipath:MAX_OPEN_FDS=4096
init.d/boot.multipath:  if [ -n "$MAX_OPEN_FDS" ] ; then
init.d/boot.multipath:      ulimit -n $MAX_OPEN_FDS
init.d/multipathd:MAX_OPEN_FDS=4096
init.d/multipathd:  if [ -n "$MAX_OPEN_FDS" ] ; then
init.d/multipathd:      ulimit -n $MAX_OPEN_FDS
rc.d/boot.multipath:MAX_OPEN_FDS=4096
rc.d/boot.multipath:    if [ -n "$MAX_OPEN_FDS" ] ; then
rc.d/boot.multipath:        ulimit -n $MAX_OPEN_FDS
rc.d/multipathd:MAX_OPEN_FDS=4096
rc.d/multipathd:    if [ -n "$MAX_OPEN_FDS" ] ; then
rc.d/multipathd:        ulimit -n $MAX_OPEN_FDS
SERVER:/etc # 

使用pam_limits（8）模块，将以下两行添加到/etc/security/limits.conf：

root hard nofile 8192
root soft nofile 8192

下次登录时，这会将root的RLIMIT_NOFILE资源限制（软和硬）增加到8192。