I'm running my own #Kubernetes cluster on bare metal at #Hetzner. I'm going through different iterations of node configurations, and trying to figure out how to squeeze the most out of a hardware configuration with a 10TB+ HDD drive and two 512GB #NVME drives. #bcache has apparently been discontinued, which leaves me with #dmcache, which is nicely built into #LVM.

One catch though: you need to create NVME cache volumes for each of the data volumes you create. This is all well and good if you're using a single volume for everything, and tools like #Longhorn work well in this kind of setup. Others, like the #OpenEBS LVM provisioner don't. There is a version in the making that just provisions raw disk images as files on whatever filesystem you have, but it's still lacking some features that are vital to me - primarily the ability to offer up StorageClasses that provision on different paths of the node, so I can pick a fast or slow filesystem to store it on.

Tips for other solutions?

Anyone know if there's a max file setting or similar for dm-cache? I'm thinking of using a small optane as a cache disk for an nvme drive for the lower latency, but somewhere there will be a breaking point for larger filers were the nvme's higher sequential speed will beat the optane. So I'd like the optane to only cache files smaller than X.

#Linux #dmcache

Maximizing hardware with SSD caching via Device Mapper: or, how I got my aging setup's startup time from 8 minutes to mere seconds thanks to Linux.

https://bojidar-bg.dev/blog/2025-02-07-dm-cache/

#linux #archlinux #dmcache #initramfs #performance #devicemapper #ssd

Just switched my root-on-SSD home/var-on-HDD setup over to a single-partition dm-cache setup which automatically caches useful blocks... and it all works!
Hopefully, this will speed up Docker and Firefox going forward. 🥲
...I did feel like a wizard when it came to writing my own mkinitcpio hook.. 😅🎩 but- thankfully I had https://wiki.tnonline.net/w/Blog/dm-cache:_Linux_Accelerated_Storage to guide me!

Would anyone be interested in a longer write-up on how I got it all working? 😇
#linux #archlinux #dmcache #initramfs

Linux dm-cache: Boosting Storage Performance with Device Mapper Cache

Introduction to dm-cache, its advantages over other caching options, and basic considerations for safe usage of this tiered storage technology.

Forza's Ramblings