@cmb:
USB flash has the same write limits as CF.
Agreed, however if the USB flash drive exceeds the max. number of writes that it can handle, it will crash and burn without crashing the entire firewall in the process. At worst it would stop showing up as a drive, and pfSense could fall back to using the flash RAM to store the files. In theory, that is. :-)
@cmb:
The only option would be to add an external hard drive for such storage, which is difficult and not supported for a variety of reasons, primarily because the partitions can't easily be split up in the fashion that would be required.
Hmm.. I'm interested in the background on why external drives aren't supported, but I have a feeling that goes outside the scope of this post. If you're so inclined, PM me with the details. If not, I certainly understand.
For the sake of argument, let's forget about external storage entirely. What about network-based storage? For instance, what if I could hypothetically mount a NFS or SMB share from pfSense to a NAS device, like FreeNAS? In that scenario the amount of storage would be virtually limitless since squidguard/squid log files are not large in the grand scheme of file storage.
As you can see, the gears in my head are turning. These devices are incredibly useful. pfSense is incredibly useful. If there's any way to overcome the finer points of using the appliance instead of a PC, I'm all about it.
Thanks (as always) in advance!