Possible to choose longhorn storage type?

[andinger]

Hi, firstly thx for this amazing project!
I have a question regarding longhorn volumes. Is it possible to decide at the moment of the concrete volume declaration, if longhorn creates the volume on the node or block storage?

Background: i want to use longhorn volumes for database persistence (should be internal ssd on the node) and a block storage volume for a big amount of files.

Thx and regards, Andi

[ifeulner]

Yes, this is possible. You need to define the storage locations and dedicated StorageClasses that use then this storage location(e.g. "nvme", "ssd"). This is done by a specific label and annotation on the nodes.

[mysticaltech]

Also, @andinger, please look at this explanation, indeed, using both kinds is possible... #369 (comment)

[andinger]

wow thx for you fast replies ... just to check, if i got your points correctly ...

• i set the longhorn_volume_size on the database nodes to create node volumes and label these nodes e.g. as db-nodes
• for the file (block storage) volumes, i need to set longhorn_volume_size=0 on the other volumes and label e.g. as storage-nodes
• i create two StorageClasses e.g. as shown in https://longhorn.io/kb/tip-only-use-storage-on-a-set-of-nodes/
• when i create the concrete volumes, i select the correct StorageClass

[mysticaltech]

@gefloh Just create a cluster with enable_longhorn and the volume size you need. Then when the cluster is up, you can create, apply new yamls related to longhorn. And if you need to fetch one from the cluster you can too. Really depends what you want to do.

[gefloh]

Ok I misunderstood this sentence under "Initial configuration". The yaml is probably not for labeling nodes, it's most probably just the default settings. What confuses me still is that according to the Longhorn docs, the value is named create-default-disk-labeled-nodes.
@mysticaltech What I want to do is use the local node storage of all worker nodes but still have one or two additional Hetzner volumes attached to one or two nodes for stuff where performance doesn't matter. Will continue experimenting.

[gefloh]

Ah ok, sorry for the confusion, now I found it, these are the values for the Longhorn Helm chart to be set in the kube.tf.

[gefloh]

Works like a charm, thanks a lot @ifeulner and @mysticaltech !

[garry-t]

@gefloh could you please explain how you achieved this? I couldn't figure out. I also want to allow use by default local storage of node and only for some node longhorn..

[andinger]

Hey guys, thanks for your support – i have been on the road quite a bit in the last two weeks so i didn't have time to check your tips. regardless ... is there a way i can sponsor this project? would love to give something back to the dev community ...

[mysticaltech]

@andinger Thanks for this kind proposal, I will add a sponsors option ASAP and let you know! 🙏 💙

[andinger]

Hey guys, i finally got it working.

• create local storage node pool with longhorn_volume_size=0
• create node pool with a specific longhorn volume size to be created as hetzner block volumes
• set annotations to the concrete nodes of the pools, e.g. node.longhorn.io/default-node-tags: ["local"] (btw. would be great if i could set the default node annotations directly in the node pool definition)
• create two longhorn based storage classes with the corresponding node selector in the parameters (https://longhorn.io/kb/tip-only-use-storage-on-a-set-of-nodes/#create-a-storageclass-that-select-a-specific-set-of-nodes)

Thx for your support!

[ifeulner]

Great - there is also more configuration possibilities via annotations: This might help here (WIP): https://gist.github.com/ifeulner/d311b2868f6c00e649f33a72166c2e5b