There are a couple of options to figure it out @Pittaya Sroilong
1. The first is, if on linux, you can look at the difference between the two following commands.
du -hs /usr/local/WowzaStreamingEngine/mediacache
du -hs --apparent-size /usr/local/WowzaStreamingEngine/mediacache
The first one is the size that mediaCache will see.
2. The second way to check is the actual utilization. When you add an item to mediaCache, you allocate the full file size to mediaCache.
You need to tune the TTL’s (Time to Live) to suit the individual use case.
With mediaCache, there are two TTLs. minTTL is used to flush items when the cache is full. maxTTL is used for normal flushing. Both timers start from when the last player stops playing a file.
We normally suggest that you need to look at the average file size x average unique streams over the TTL period to make sure you have a large enough store and low enough TTLs.
If doing ABR streaming then you need to use the sum of all the ABR rendition file sizes in the calculation because we will reserve cache space for all of the files.