If you are using Iguana on Unix, Linux or Mac OS X, and you are running a large number of channels, you must ensure that your system allows enough simultaneous open files. If the open file limit is set too low, you may start to notice unusual behavior, such as SQL I/O errors.

To check the limit imposed by your system on the number of open files, run the ulimit -a command:

$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) 6144
file size               (blocks, -f) unlimited
max locked memory       (kbytes, -l) unlimited
max memory size         (kbytes, -m) unlimited
open files                      (-n) 256
pipe size            (512 bytes, -p) 1
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 266
virtual memory          (kbytes, -v) unlimited

In the output from this command, the open files line indicates the upper limit on the number of files that can be open at one time. If you use ulimit -n to increase this limit, the errors should stop occurring. Setting a value of 1024 is best:

ulimit -n 1024