The 1950 will support Windows Server 2003, 03 x64, 2000, and SBS 2003 R2. The largest validated drives appear to be 4TB NL-SAS 3.5" drives.
EDIT: The spec sheets are what I referenced, and as Flash indicated, support for 2012R2 was added.
The largest validated SATA drive was 2TB. I would not expect 2012 R2 to work, considering that not even 08 or 08 R2 were tested.
Servers 2008, 2008 R2, 2012, AND Server 2012 R2 ARE validated on the PowerEdge 1950 - see link below for drivers. (Public spec sheets are out of date.)
Make sure you update your system firmware (BIOS, RAID, BMC, etc.) before installing 2012 R2.
Drive size depends on the controller!
PERC 6/I (which you do have) does NOT support pass-through (RAID only), and 2TB is the largest drive it will support - SAS or SATA.
SAS 6/iR (which you do not have) supports pass-through (non-RAID) … in RAID, 2TB is the largest drive it will support (SAS or SATA); in non-RAID, larger drives will work but it may be hit/miss if using non-certified/validated drive models.
Thank you all for all your contributions.
Finally I installed W2012 R2 and I have not had any problem.
I have used two 500GB SSDs in RAID1 and the server performance is much higher than the server had with conventional disks.
I would like to install the DELL monitoring software to send me alerts if something goes wrong. What software and in what version should I install it?