Choosing the right HDDs drives for a RHEL Host

Hello,

I am going to set up a VM host with a Refurfished 2x Intel Xeon E5345 and 16GB of RAM. As the server does not come with any drives, I need to buy a new ones.

I have four choices, getting 2x drives of 1TB or getting one drive of 2TB (also Seagate or WD), ¿What do you think is the most reliable? I have read tons of reviews and I could not determine what's the best option for this envoronment. All the content of the server is going to be backed-up daily in a RAID 1 NAS of 1TB (obviously only less than 1TB can be backed-up), so 2x 1TB RAID 1 is not needed in the server. I do not need nor want RAID 0 in the VM Host because a single disk failure ruins everything.

¿Is better a bigger drive or two smaller drives? I do not need a very high performance environment, because only 2-4 low-load VMs are going to be run on the server. I think two drives of 1TB let me allocate some VMs on one disk, and the RHEL O.S. and other VMs in the other drive, so better performance is expected.

The HDD drives will run 24x7 because one of the VM is an Active Directory.

The drives in detail:

1) 2x Seagate Barracuda 7200.14 ST1000DM003 1TB 64MB Caché 7200rpm SATA 3
2) 2x Western Digital Caviar Black 1TB 7200rpm 64MB caché SATA 3
3) 1x Seagate Barracuda 7200.14 ST2000DM001 2TB 64mb Caché 7200rpm SATA 3
4) 1x Western Digital Caviar Black 2TB 7200rpm 64MB caché SATA 3

As English is not my native language, please excuse typing errors.

Thanks in advance,

Jorge Garcia