Ceph – Create custom CRUSH rules for SSD Not Working


New Member
Jul 20, 2019
I want to build 3 server nodes Proxmox HCI Cluster

Server Nodes :2x Dell Poweredge 730 & 1x Dell Poweredge R430
NIC : 2x 10 Gigabit for ceph and 2x 1gig NIC in each node
Storage : 4x 1TB Read Intensive SSDs in each node (1 for Proxmox OS and 3 for cache)
Recently added New Storage : 3x 8TB SATA HDD for Storagein each node

Now i want to maje seperate pool of SSDs for cache and HDDs for Storage
But commadn $ceph osd tree shows that all disk types are HDD including my SSD disk

This command gives error
ceph osd crush rule create-replicated ssd-only default osd ssd

Error EINVAL: device class ssd does not exist
Bundle of Thanks Alwin , It works ..... Can you please recommend me one more thing i have 4x 8TB HDDs on each of the 3 nodes. Please guide that 3x 1TB SSD on each node will be sufficient for cache in ceph cluster?
It will improve the speed/latency of an OSD. But I can't tell you if it will be sufficient for your use case.


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