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No wonder. SSD gives you raw storage. You're losing some (at worst could be even 50%) for redundancy just to start. SAN Flash controllers are hideously expensi
by ilyt 3y ago
No wonder. SSD gives you raw storage. You're losing some (at worst could be even 50%) for redundancy just to start.
SAN Flash controllers are hideously expensive because they need to push tens/hundreds worth of SSDs to tens of servers.
If you can solve redundancy other way (say via pair of replicated databases), a pair of servers with local storage will be far more $ effective
- pgwhalen 3y agoTrue, but it's not as though the 10X expense is for nothing. A SAN enables a lot more than local storage. I didn't mean to suggest that there wasn't a way to achieve lower costs on storage hardware directly, just that in practice, for a variety of reasons, that quoted cost is not representative.
- ilyt 3y agoAnd in case of database it doesn't give you much. You still need 2 nodes for redundancy, if you don't need a rack's worth of storage for that database, using SAN for that is waste of money. I know the corporate idea of "everything on SAN, nothing outside of SAN" very well, it's just plainly solving political problems, not techncial ones.
- pgwhalen 3y agoYour understanding of SAN usage is narrow, and incorrect in the case of my organization. One major benefit that SAN-backed database storage provides us is, when combined with VMs, enables us to spin up another database instance against already existing data in the SAN (i.e. a staging DB that looks at prod data).