When using RAID10 + BBWC why is it better to separate PostgreSQL data files from OS and transaction logs than to keep them all on the same array?
- by Vlad
I've seen the advice everywhere (including here and here): keep your OS partition, DB data files and DB transaction logs on separate discs/arrays. The general recommendation is to use RAID1 for OS, RAID10 for data (or RAID5 if load is very read-biased) and RAID1 for transaction logs.
However, considering that you will need at least 6 or 8 drives to build this setup, wouldn't a RAID10 over 6-8 drives with BBWC perform better? What if the drives are SSDs?
I'm talking here about internal server drives, not SAN.