memory vs disk cache for large media files

[me at ibotty.net]

hi,

> dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync

unfortunately that does not tell you what delay you have to expect.
varnish will in most cases only have many scattered reads. so you better
test those. be sure to test for a longer time. you might be on the same
computer as a virtual machine that has a disk-intensive workload only
during specific times.

good luck though,
 tobias florek