Please disable transparent hugepage

[JOduMonT]

would be nice to disable the THP

error from nextcloud

Jun 24 11:56:39 14:M 24 Jun 04:56:39.893 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.

more info about why it should be considered

• https://stackoverflow.com/questions/42591511/when-to-turn-off-transparent-huge-pages-for-redis
• https://redis.io/topics/latency

[nebulon]

In this case we have to do this for the whole server. Not sure yet if that is a good idea or not, since there are various different payloads. However from what I've read so far, especially databases, not just redis, could profit. As also mentioned for mongodb at https://docs.mongodb.com/manual/tutorial/transparent-huge-pages/

That being said in the servers I have checked now, the default actually seems to be madvise for THP, which according to https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/performance_tuning_guide/sect-red_hat_enterprise_linux-performance_tuning_guide-configuring_transparent_huge_pages is a much better option as the process can control the behavior on its own.

I might be wrong but it seems the recommendation for option never is a bit outdated by now?

[JOduMonT]

@nebulon said in Please disable transparent hugepage:

I might be wrong but it seems the recommendation for option never is a bit outdated by now?

hopefully,

thank for your research, I forget to look before.

I'll forward these to nextcloud, maybe they have to update their warning

the first time I eared about it in a talk from Brendan Gregg (Netflix) and I was full of hope by using RIP CoreOS

[nebulon]

Thanks, if you forward that information publicly and have a link, it would be great if you can put it here so we can also follow such a thread.

[girish]

This warning is coming from redis and not from nextcloud (so I don't this the nextcloud devs can help)

[JOduMonT]

@nebulon said in Please disable transparent hugepage:

if you forward that information publicly and have a link

I know I do play renagate here
https://github.com/redis/redis-rcp/issues/22

[girish]

Thanks for reporting upstream Let's wait for their response.

[JOduMonT]

FYI, whonix also recommend to disable HugePage as it is possible to tamper the data on transit
https://www.whonix.org/wiki/KVM#HugePages