Question: Does anyone know if I can install normal 2.5" SATA drives inside an HP DL360 G5 server? Right now it has 6 72GB SAS drives. I am looking for raw storage for my files SAS performance in not required.

Answer: 
I've never had any compatibility issues using SATA disks in HP hardware or with Smart Array controllers. 

A better solution may be to use midline SAS drives if you have the budget. They'll still run at 7200 RPM, but still have a SAS interface (and queuing, etc.). 

I'd recommend the [2.5" Seagate Constellation drives](http://www.seagate.com/www/en-us/products/enterprise-ssd-hdd/constellation/) in either 500GB or 1TB capacities, with a SAS-2 interface. They should be around $200 per disk. The SATA interface versions of the same drives will be about $50 less per disk.

The [HP ProLiant DL360 G5 server](http://h18000.www1.hp.com/products/quickspecs/12476_div/12476_div.html) uses a Smart Array P400i RAID controller in most setups. Performance is helped tremendously if you have a battery-backed write cache unit on the controller. See: [Incredibly low disk performance on HP ProLiant DL385 G7](https://serverfault.com/questions/221541/incredble-low-disk-performance-on-hp-dl385-g7/221553#221553)

Make sure you update the firmware on your internal Smart Array (P400) RAID controller before doing this. See the [HP firmware update page for your model and OS](http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?lang=en&cc=us&prodNameId=3288144&taskId=135&prodTypeId=15351&prodSeriesId=1121486&lang=en&cc=us).
You can use SATA drives, but make sure they are "raid edition" drives intended for use in servers, and not drives intended for use in desktops. "Raid Edition" is Western Digital's name for it: other vendors each have their own name, but this is important; it's not just snake oil and you can run into problems if you get cheaper disks.

Expect to spend about $100 for a 1TB disk of this type:  

[http://www.amazon.com/Western-Digital-Cache-Enterprise-Drive/dp/B001IEXU68](http://rads.stackoverflow.com/amzn/click/B001IEXU68)  

or $120 for a more recent version with a larger cache:  

[http://www.amazon.com/Western-Digital-Cache-Enterprise-WD1003FBYX/dp/B003SANWI6](http://rads.stackoverflow.com/amzn/click/B003SANWI6)