I have /var on a 10Gb EXT4 partition separate from /. I want to stick /var/cache in RAM using tmpfs. The /etc/fstab entry would be quite simple:tmpgs /var/cache tmpfs size=500M,rw,nodev,nosuid,noexec,noatime 0,0However, I notice that without this entry du -sh shows the size-on-disk as:# du -sh /var/cache215M    /var/cacheYet if I apply the above fstab entry, reboot, and run du -sh again I get:# du -sh /var/cache160K    /var/cacheWithout the tmpfs entry the folders ldconfig, yum, fontconfig and man are present. When using the tmpfs fstab entry only the latter two are present.I'm curious about this because:I don't understand when to use the bind mount flag.I have /run in a tmpfs mount and now I'm not so sure about the contents of that mount being the same as what would be present if I didn't.Why is this?
Tmpfs mount for directories on another partition
mount;fstab;tmpfs