I’m looking to upgrade one of my site servers. The site currently executes around 20m sql queries a day and this is growing quite fast. Right now IO throughput is a real issue, so my idea is to move various databases onto their own disk pairs. My idea is to do something like this:
Disk 1 & Disk 2 / Raid 5,6 or 10 (SAS or SSD) - database 1
Disk 3 & Disk 4 / Raid 5,6 or 10 (SAS or SSD) - database 2
Disk 5 & Disk 6 / Raid 5,6 or 10 (SAS or SSD) - database 3
Disk 7 (SSD) - Transaction Logs
Disk 8 (SSD) - Transaction Logs
My experience is lacking here, so got a few questions:
1) Firstly, does the above look stupid?
2) Is there anything I should look out for in the RAID controller, eg. Bandwidth throughput when using SSD?
3) Are all SSD disks created equal? I’ve picked up threads saying that certain types are substandard?
4) I’m assuming that for simple two disk mirrors any of those RAID levels will be ok? Bad assumption?
5) Any other tweaks to make this config better?
My site is highly transactional, but the databases aren’t that big, only a couple of gigs currently. So my major scaling requirement is IO, not size.. I’ll be throwing a lot of RAM at the box as well to put more indexes in memory etc..