aix下oracle用户下执行sqlplus / as sysdba相当慢

有套11.2.0.4 rac+aix 6.1 环境（两节点），在oracle用户下执行sqlplus后需要等待很长时间才会有结果，而在grid用户下返回就很快。附件是truss跟踪日志。日志看有很多sleep，初步怀疑是加固导致的。

大概查到问题原因了，应该是配了DNS解析，刚好这个解析有问题，需要等待15秒超时，检查下相关配置吧。

7733360: 60031055: 0.2531:        kopen("/etc/resolv.conf", O_RDONLY) = 8
7733360: 60031055: 0.2533:        kioctl(8, 22528, 0x0000000000000000, 0x0000000000000000) Err#25 ENOTTY
7733360: 60031055: 0.2535:        kioctl(8, 22528, 0x0000000000000000, 0x0000000000000000) Err#25 ENOTTY
7733360: 60031055: 0.2598:        kopen("/etc/hosts", O_RDONLY) = 8
7733360: 60031055: 0.2609:        kopen("/etc/hosts", O_RDONLY) = 8
7733360: 60031055: 0.2611:        kioctl(8, 22528, 0x0000000000000000, 0x0000000000000000) Err#25 ENOTTY
7733360: 60031055: 0.2612:        kfcntl(8, F_SETFD, 0x0000000000000001) = 0
7733360: 60031055: 0.2614:        kioctl(8, 22528, 0x0000000000000000, 0x0000000000000000) Err#25 ENOTTY
7733360: 60031055: kread(8, " #   I B M _ P R O L O G".., 4096) = 2315
7733360: 60031055: kread(8, " #   I B M _ P R O L O G".., 4096) = 0
7733360: 60031055: 0.2619:        socket(2, 2, 0)= 9
7733360: 60031055: 0.2621:        getsockopt(9, 65535, 4104, 0x0FFFFFFFFFFF7484, 0x0FFFFFFFFFFF7480) = 0
7733360: 60031055: 0.2622:        connext(9, 0x09001000A0021E18, 16) = 0
7733360: 60031055: 0.2624:        _esend(9, 0x0FFFFFFFFFFF83B0, 23, 0, 0x0000000000000000) = 23
7733360: 60031055: 2.2627:        _poll(0x0FFFFFFFFFFF7550, 1, 5000) (sleeping...)
7733360: 60031055: 2.2627:        _poll(0x0FFFFFFFFFFF7550, 1, 5000) = 0
7733360: 60031055: 5.2628:        close(9)= 0
7733360: 60031055: 5.2630:        socket(2, 2, 0)= 9
7733360: 60031055: 5.2632:        getsockopt(9, 65535, 4104, 0x0FFFFFFFFFFF7484, 0x0FFFFFFFFFFF7480) = 0
7733360: 60031055: 5.2633:        connext(9, 0x09001000A0021E18, 16) = 0
7733360: 60031055: 5.2635:        _esend(9, 0x0FFFFFFFFFFF83B0, 23, 0, 0x0000000000000000) = 23
7733360: 60031055: 7.2638:        _poll(0x0FFFFFFFFFFF7550, 1, 10000) (sleeping...)
7733360: 60031055: 7.2638:        _poll(0x0FFFFFFFFFFF7550, 1, 10000) = 0
7733360: 60031055: 15.2639:        close(9)= 0
7733360: 60031055: 15.2641:        socket(2, 2, 0)= 9
7733360: 60031055: 15.2642:        getsockopt(9, 65535, 4104, 0x0FFFFFFFFFFF7484, 0x0FFFFFFFFFFF7480) = 0
7733360: 60031055: 15.2644:        connext(9, 0x09001000A0021E18, 16) = 0
7733360: 60031055: 15.2646:        _esend(9, 0x0FFFFFFFFFFF83B0, 23, 0, 0x0000000000000000) = 23
7733360: 60031055: 17.2649:        _poll(0x0FFFFFFFFFFF7550, 1, 20000) (sleeping...)
7733360: 60031055: 17.2649:        _poll(0x0FFFFFFFFFFF7550, 1, 20000) = 1
7733360: 60031055: 26.0927:        _enrecvfrom(9, 0x0FFFFFFFFFFF9700, 1024, 0, 0x0FFFFFFFFFFF7D10, 0x0FFFFFFFFFFF7538, 0x0000000000000000) = 23
7733360: 60031055: 26.0929:        close(9)= 0
7733360: 60031055: 26.0931:        close(8)= 0

如/etc/resolv.conf文件内容如下

nameserver 192.168.50.2

search localdomain

将nameserver注释掉就好了。