/var RAMDISK size (running Squid) and i386 system memory considerations
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Running 2.2-RELEASE i386 with Squid (on bare metal). 2.0GB of RAM
Being slightly concerned about memory, I started out by doubling the defaults for both /tmp and /var so I was using 80MB for /tmp and 120MB for /var. I quickly found out that I was not using nearly the 80MB I had set for /tmp so I dropped it down to 64MB and it has been fine for several months. Under heavy loads the /tmp RAMDISK gets up to 8-12% usage but usually stays down around 4-6% so that's that.
However /var is a different story and I am having a tough time sizing it properly. I understand that running Squid does and will make that very difficult having not relocated Squid cache. I had started by doubling the default 60MB up to 120MB but was hitting high 90's% straight away so I doubled that and moved it up to 256MB. That hit 98% the very first day… so I doubled that up to 512MB. The /var RAMDISK dashboard daemon usually sits around 8-12% and at times will rise to upwards of 80% but I have never seen it go higher than that.
Is this the type of thing that I can either move the Squid cache directory or just play around with it until I find a good size given my needs? At what point do I need to start worrying that I am taking away too much RAM from the system by raising the size of the /var RAMDISK? I say that the /tmp and /var RAMDISK sizes fluctuate because about once a month I have a planned reboot (has been more frequent in recent months) so they reset on reboot.
I have many spares of the hardware that I am running i386 pfsense on so I am reluctant to upgrade to an x64 OS. Also the OS disk is running on a (very old) 80GB 10k RPM HDD so disk writes are not really a concern.
Looking to learn at what point should I just relocate the squid cache directory because the size of my /var RAMDISK is going to impact overall system performance... and is there a decent rule of thumb for the /var RAMDISK size or will my mileage vary depending on bandwidth and use?
Regards,