Actually, it is a satellite for this question: ESXi: unable to mark SSD drive as SSD, but I just thought I would raise a separate question, since this question is not related to the error I bumped into, but rather related to the proper ESXi configuration at the first place.
So I have a DELL PowerEdge R630 server with the following disks:
- HDD RAID 5 built from three HDD disks 1 TB each (in total, it provides 1.9 TB)
- A separate SSD disk (900 GB)
There going to be lots of machines on this server, and for some of them, I would like to provide the highest performance. With this goal in mind:
- Does it make sense to install ESXi on a SSD disk, or I'd better install it on HDD RAID 5?
- Does it make sense to place on SSD those virtual machines from which I have the highest performance?
For p.2, I think it makes sense, but I am not that sure about p.1. Or, maybe I wrong for p.2, as well?
Best Answer
To the best of my knowledge ESXi loads itself completely into RAM at boot time. It might use the storage it booted from for logging and crash dumps (there are advanced settings to control this) but shouldn't need high storage performance to run. So: No, I wouldn't waste my precious SSDs for ESXi.
This depends on the needs of the VM. SSDs should give you more IOps / lower latencies but if your workload doesn't benefit from this- where's the point? Databases generally should benefit from SSDs, bitcoin mining (as an example) shouldn't.