I have to run clamav on large files. I was wondering which command was the fastest between clamscan and clamdscan. But it seems that clamdscan is not working properly: it scans file larger than 1 GB. Could you guys help me find why the heck clamdscan isn't working ? Between clamscan and clamdscan which one is less resource consuming ? I run ClamAV 0.97.8/18037 on Ubuntu 12.04.3 LTS. Please find below the execution result of both commands: clamscan myfile.zip ----------- SCAN SUMMARY ----------- Known viruses: 2864504 Engine version: 0.97.8 Scanned directories: 0 Scanned files: 1 Infected files: 0 Data scanned: 0.00 MB Data read: 1024.16 MB (ratio 0.00:1) Time: 9.145 sec (0 m 9 s) clamdscan myfile.zip /home/ubuntu/workspace/benchmark/myfile.zip: OK ----------- SCAN SUMMARY ----------- Infected files: 0 Time: 0.000 sec (0 m 0 s) And here are the clamav log file: Wed Oct 30 10:26:32 2013 -> Received POLLIN|POLLHUP on fd 4 Wed Oct 30 10:26:32 2013 -> Got new connection, FD 9 Wed Oct 30 10:26:32 2013 -> Received POLLIN|POLLHUP on fd 5 Wed Oct 30 10:26:32 2013 -> fds_poll_recv: timeout after 5 seconds Wed Oct 30 10:26:32 2013 -> Received POLLIN|POLLHUP on fd 9 Wed Oct 30 10:26:32 2013 -> got command CONTSCAN /home/ubuntu/workspace/benchmark/myfile.zip (51, 7), argument: /home/ubuntu/workspace/benchmark/myfile.zip Wed Oct 30 10:26:32 2013 -> mode -> MODE_WAITREPLY Wed Oct 30 10:26:32 2013 -> Breaking command loop, mode is no longer MODE_COMMAND Wed Oct 30 10:26:32 2013 -> Consumed entire command Wed Oct 30 10:26:32 2013 -> Number of file descriptors polled: 1 fds Wed Oct 30 10:26:32 2013 -> fds_poll_recv: timeout after 3600 seconds Wed Oct 30 10:26:32 2013 -> THRMGR: queue (single) crossed low threshold -> signaling Wed Oct 30 10:26:32 2013 -> THRMGR: queue (bulk) crossed low threshold -> signaling Wed Oct 30 10:26:32 2013 -> /home/ubuntu/workspace/benchmark/myfile.zip: OK Wed Oct 30 10:26:32 2013 -> Finished scanthread Wed Oct 30 10:26:32 2013 -> Scanthread: connection shut down (FD 9) Wed Oct 30 10:26:32 2013 -> THRMGR: queue (single) crossed low threshold -> signaling Wed Oct 30 10:26:32 2013 -> THRMGR: queue (bulk) crossed low threshold -> signaling