still need cache & wal disk for ceph storage with all SSD ？

[gzbenson]

I want to build 3 servers for lab and run SMB applications ( small company , just 20 users ) : DEV-test environments ( 10 VMs , gitlab , jerkin , Sonar , nextcloud ...)

system disk ：2 x 480G sata ssd mirror per server

RAM: 32GB x 4 ECC per server

CPU: 1 x D1581 per server

storage disk for ceph : 3 x 1.92T sata enterprise ssd per server

network : 2 x 1GE port and 1 x 10GE port per server

do i still need to add one or more nvme disk per server for cache & wal disk for ceph storage with all SSD ？

 

[Drzga]

No,

depending on your SSD choice (go for lowest latency) you should be totally fine. Make sure to use 10G network for Ceph.
You're a bit low on RAM imo.
If you run Ceph replica 3/2 you can simply add WAL & DB one by one later on (destroy & create OSDs or hit the Ceph config).
Hoping this is not too late =)

Kind Regards

 

[LnxBil]

storage disk for ceph : 3 x 1.92T sata enterprise ssd per server

Depends if you want to spend more money. The difference is not that big as the difference is between spinning rust and SSDs. Those are SATA SSDs, so of course there is something faster: Optane PCIe NVMe. Mine are roughly 4-5 times faster in latency as my enterprise SSDs. The question is if you need this.

Make sure to use 10G network for Ceph.

or even more: 25G is the new 10G, optimize the network.