I’m going setup two new OLTP servers with CentOS 6 and Percona 5.5 or 5.6 (not yet decided).
This will be Dell servers with PERC H710 controller.
I have ~3500+ DML/sec and ~14000 SELECT/sec on both.
I will use 6 HDD - SAS 15kRPM 600GB for OS and database. Binary logs on master and backups on slave will have separate drives.
Currently I have 4x300Gb 15kRPM arrays for data. Master server have average IO size ~40 sectors (512bytes) and slave server have average IO size ~60 sectors.
Till this day I thought that optimal stripe size for random IO on OLTP DB server should match avgrq-sz
So according to this, I should use 16 or 32kByte stripe size for master and 32kByte stripe size for slave
But here is bit outdated (PERC5-related) guide from Dell “Optimizing RAID Storage Performance” http://www.dell.com/downloads/global/power/ps3q07-20070368-Olivarez-OE.pdf
Just a quote from there:
Large stripe element size mean big stripe size. Every time DB will write few pages to disk, my RAID controller will read whole big stripe, modify only small part of big stripe and write it back to disk… Or not? So I need an advice.
And also I need a good advice about paririon alignement - if there any partitoning tool which I can use with option like ‘–align-to-64k’ or at least some way to verify that CentOS installer choose correct partition boundaries ?
Thank you in advance.