Erasure code overhead for heterogeneous hardware

cn flag

I need to setup a Ceph cluster on a set of 10 machines having different disk sizes and numbers. The numbers ranges from 16x500GB to 8x4TB, with various intermediate values, the most common being 8x2TB. My idea is to go for a k=6 m=2 erasure code with host failure domain, but I don't know how to get an estimate of the expected available disk space. Most (if not all) of the examples I found about how to calculate erasure code overhead assume a simple setup with identical disks and hosts, so they are of little use in my case.


Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.