what's the optimal partition setup for a linux db server? My host wants to know how I want to partition my server before installing CentOS. I need to be able to do use xtrabackup to create quick backups from 20-50GB databases. I know I need to use a LVM, but I'm not sure how I would forward that to my host?

I currently have 1TB of usable space in RAID-10, how should I partition the array? this is only going to be a db server, only mysql and OS will be on this server.
Most of the partitioning of data in SQL Server is done for performance, recover-ability (separating log/data files to different physical disk arrays), and then management of data.  For example, if you have different logical drive letter names, you could look at the IO metrics for them separately through your monitoring solution.

It looks like you only have 1 large RAID 10 with 1TB of total usable storage.  Correct?  If so, at the end of the day, it's not going to matter too much from an architecture point of view since your hands are tied to having everything on the same spindle.

Now as to how to setup the drives on the LinuxOS, it depends on the scope and scale of the servers lifetime.  I'll let your guys decide on that how that should look outside of the vanilla:


1- swap (RAM X2 or whatever you guys decide) 
2- /boot (Usually small primary partition - ext3)  
3- / (big data drive)
4- / (log drive)
5- / (Backup Drive)


I would advise on separating the data and log drives for more granular performance metric collection, and separating the backup drive so they don't balloon up to a point where your data files have no room to grow.  Make sure to pre-grow your files when installing.

Again this is highly subjective and many opinions might differ.  Implement what makes most sense to you.