CoW with webserver databases: innodb_file_per_table and dedicated tables for blobs?

[Ingvar Bogdahn <ingvar.bogdahn@googlemail.com>]

Hello there,

I'm planing to use btrfs for a medium-sized webserver. It is commonly 
recommended to set nodatacow for database files to avoid performance 
degradation. However, apparently nodatacow disables some of my main 
motivations of using btrfs : checksumming and (probably) incremental 
backups with send/receive (please correct me if I'm wrong on this). 
Also, the databases are among the most important data on my webserver, 
so it is particularly there that I would like those feature working.

My question is, are there strategies to avoid nodatacow of databases 
that are suitable and safe in a production server?
I thought about the following:
- in mysql/mariadb: setting "innodb_file_per_table" should avoid having 
few very big database files.
- in mysql/mariadb: adapting database schema to store blobs into 
dedicated tables.
- btrfs: set autodefrag or some cron job to regularly defrag only 
database fails to avoid performance degradation due to fragmentation
- turn on compression on either btrfs or mariadb

Is this likely to give me ok-ish performance? What other possibilities 
are there?

Thanks for your recommendations.

ingvar