Operating system name and version: CentOS 5.0 (Linux VSIAPP08 2.6.18-194.el5PAE #1 SMP Fri Apr 2 15:37:44 EDT 2010 i686 i686 i386 GNU/Linux)
Version of smsd: 3.1.15
Smsd installed from: sources
Name and model of a modem / phone: wavecom
Interface: USB

I got the following log (/var/log/smsd_test.log) while executing your test scenario (http://smstools3.kekekasvi.com/topic.php?id=548):

2013-07-17 14:10:50.151,5, smsd: Moved file /var/spool/sms_test/outgoing/-113- to /var/spool/sms_test/checked 2013-07-17 14:10:56.043,5, smsd: Moved file /var/spool/sms_test/outgoing/-114- to /var/spool/sms_test/checked 2013-07-17 14:11:00.342,5, smsd: Moved file /var/spool/sms_test/outgoing/-115- to /var/spool/sms_test/checked 2013-07-17 14:11:00.557,5, GSM1: Took 5.9 seconds to get a file /var/spool/sms_test/checked/-104-, lost 0 times, 11 SMS files and 1 LOCK files seen. 2013-07-17 14:11:00.557,5, GSM1: Test run, NO actual sending: from to 10000104 2013-07-17 14:11:06.565,5, GSM1: SMS sent, Message_id: 1, To: 10000104, sending time 6 sec. 2013-07-17 14:11:09.650,5, smsd: Moved file /var/spool/sms_test/outgoing/-116- to /var/spool/sms_test/checked 2013-07-17 14:11:17.053,5, smsd: Moved file /var/spool/sms_test/outgoing/-117- to /var/spool/sms_test/checked 2013-07-17 14:11:18.843,5, GSM1: Test run, NO actual sending: from to 10000105 2013-07-17 14:11:23.851,5, GSM1: SMS sent, Message_id: 1, To: 10000105, sending time 5 sec. 2013-07-17 14:11:24.158,5, smsd: Moved file /var/spool/sms_test/outgoing/-118- to /var/spool/sms_test/checked 2013-07-17 14:11:30.236,5, smsd: Moved file /var/spool/sms_test/outgoing/-119- to /var/spool/sms_test/checked 2013-07-17 14:11:40.540,5, GSM1: Took 11.6 seconds to get a file /var/spool/sms_test/checked/-106-, lost 0 times, 14 SMS files and 1 LOCK files seen. 2013-07-17 14:11:40.540,5, GSM1: Test run, NO actual sending: from to 10000106 2013-07-17 14:11:41.415,5, smsd: Moved file /var/spool/sms_test/outgoing/-12- to /var/spool/sms_test/checked 2013-07-17 14:11:45.422,5, GSM1: SMS sent, Message_id: 1, To: 10000106, sending time 5 sec. 2013-07-17 14:11:46.206,5, smsd: Moved file /var/spool/sms_test/outgoing/-120- to /var/spool/sms_test/checked 2013-07-17 14:12:23.259,5, smsd: Moved file /var/spool/sms_test/outgoing/-121- to /var/spool/sms_test/checked 2013-07-17 14:12:27.239,5, GSM1: Test run, NO actual sending: from to 10000107 2013-07-17 14:12:31.119,5, smsd: Moved file /var/spool/sms_test/outgoing/-122- to /var/spool/sms_test/checked 2013-07-17 14:12:39.130,5, GSM1: SMS sent, Message_id: 1, To: 10000107, sending time 12 sec. 2013-07-17 14:12:41.608,5, smsd: Moved file /var/spool/sms_test/outgoing/-123- to /var/spool/sms_test/checked 2013-07-17 14:12:46.350,5, smsd: Moved file /var/spool/sms_test/outgoing/-124- to /var/spool/sms_test/checked 2013-07-17 14:12:51.597,5, GSM1: Took 5.7 seconds to get a file /var/spool/sms_test/checked/-108-, lost 0 times, 18 SMS files and 1 LOCK files seen. 2013-07-17 14:12:51.598,5, GSM1: Test run, NO actual sending: from to 10000108 2013-07-17 14:12:52.578,5, smsd: Moved file /var/spool/sms_test/outgoing/-125- to /var/spool/sms_test/checked 2013-07-17 14:13:03.535,5, smsd: Moved file /var/spool/sms_test/outgoing/-126- to /var/spool/sms_test/checked 2013-07-17 14:13:04.535,5, GSM1: SMS sent, Message_id: 1, To: 10000108, sending time 13 sec. 2013-07-17 14:13:09.001,5, smsd: Moved file /var/spool/sms_test/outgoing/-127- to /var/spool/sms_test/checked 2013-07-17 14:13:19.669,5, GSM1: Took 9.2 seconds to get a file /var/spool/sms_test/checked/-109-, lost 0 times, 21 SMS files and 1 LOCK files seen. 2013-07-17 14:13:19.669,5, GSM1: Test run, NO actual sending: from to 10000109 2013-07-17 14:13:19.669,5, smsd: Moved file /var/spool/sms_test/outgoing/-128- to /var/spool/sms_test/checked 2013-07-17 14:13:28.296,5, smsd: Moved file /var/spool/sms_test/outgoing/-129- to /var/spool/sms_test/checked

sms-file processing in checked folder took longer than expected. It took more than 5 seconds to process 1 file in checked folder.
In my production environment, even took longer than 30 seconds

Any idea, whats wrong with my server setup?