Disable transparent huge pages

[btd]

According to Redis Administration Guide they recommend to disable this feature.

[DavidWittman]

Good idea @btd. We'll need to find a way to make this persist across a reboot. Perhaps it should be added to the init script. It would be nice to also have this feature be toggle able. Appreciate any thoughts you have on that.

[btd]

I copied this snippet from ansible-oracle, they also add this line to grub. I am not sure how portable it is.
For my use case i usually never reboot server, just spawn new VM with fresh redis, do migration and terminate old.

[btd]

By idea grub.conf should be regenerated when new kernel installed.

[cjamison]

I did some research into this and there seems to be a lot of problems with grub solutions and there are so many cases depending on the platform and even the hosting provider.

What seems to be the easiest thing is to add the check and setting to the init scripts. That worked for me.

[DavidWittman]

@cjamison mind sharing your init script changes? Thanks!

[cjamison]

I just added this before the case statement:

if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
   echo never > /sys/kernel/mm/transparent_hugepage/enabled
fi

[awr]

Here's an approach that seems to work across reboots affinity@f626839 based on https://docs.mongodb.com/manual/tutorial/transparent-huge-pages/

[DavidWittman]

I'm going to close this in favor of #153