> Ceph can make it possible but for fast disk I/O, it's tough to beat the local SAS bus.
Personal anecdote - we have everything on-prem using a pretty standard vSphere setup, I've got a couple PostgreSQL databases that aren't even that heavily used (I mean, they top out around 20-40 tx/sec) backed by a hybrid Tegile array. Randomly throughout the day my IOWAIT starts spiking because even over 8Gb fiber channel our storage latency starts spiking because everything else is on the same storage (well over 200 full VM's), or sometimes I need to run a table scan over a 40GB table for a one-off query and the storage bottlenecks the crap out of us because only our small active set is cached on the SSD's.
You can run databases on remote storage, people obviously do it, but there's a reason why even on AWS the best practice is to use your instance disks instead of EBS volumes if you care about performance. Noisy neighbors suck.
Personal anecdote - we have everything on-prem using a pretty standard vSphere setup, I've got a couple PostgreSQL databases that aren't even that heavily used (I mean, they top out around 20-40 tx/sec) backed by a hybrid Tegile array. Randomly throughout the day my IOWAIT starts spiking because even over 8Gb fiber channel our storage latency starts spiking because everything else is on the same storage (well over 200 full VM's), or sometimes I need to run a table scan over a 40GB table for a one-off query and the storage bottlenecks the crap out of us because only our small active set is cached on the SSD's.
You can run databases on remote storage, people obviously do it, but there's a reason why even on AWS the best practice is to use your instance disks instead of EBS volumes if you care about performance. Noisy neighbors suck.