Making stripe_cache_size permanent

Add a udev rule, e.g. to /etc/udev/rules.d/60-md-stripe-cache.rules:

SUBSYSTEM=="block", KERNEL=="md*", ACTION=="change", TEST=="md/stripe_cache_size", ATTR{md/stripe_cache_size}="8192"

I haven't actually tried this so it might not be 100% right (may be some typos), but it should be close. Check man udev to understand more.

You may also want to run the following commands afterwards to immediately apply the new rule:

udevadm trigger
udevadm control --reload-rules