In which case, which is theoretically better (since I don't have a convenient test bed at the moment) for WAL in a write-heavy environment? More disks in a RAID 10 (which should theoretically improve write throughput in general, to a point) or a 2-disk RAID 1? Does it become a price/performance question, or is there virtually no benefit to throwing more disks at RAID 10 for WAL if you turn off journaling on the filesystem?
Over 4 drives, I would gather that RAID 10 wouldn't gain you anything. Possibly over 6 or 8 however, it may be faster because you are writing smaller chunks of data, even if two copies of each.
Sincerely, Joshua D. Drake -- === The PostgreSQL Company: Command Prompt, Inc. === Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240 Providing the most comprehensive PostgreSQL solutions since 1997 http://www.commandprompt.com/