HP Proliant ML350 G5 server goes unresponsive frequently

[azkerm]

Hi There,

I have got an old ML350 G5 server with us just running with a ESXi 5.0. I have also got a single VM (win 2008 R2) running with it. There are just two disk (2x 73.4 GB, 15k RPM, SAS) connected on a RAID1.

Since two weeks, the server goes unresponsive very frequently leaving red LED's on the server. Thus, I had a quick read over the maintenance guide and found out that it shows the server internet/external health LEDs were flashing red while leaving the server not responsive.

However, later today I had the smartstart booted to do a diagnosis on the server to see if I can crawl any information. 

I have all the information and the only error I have seen is that disk 1 is failed (attached). 

What I wanted to know is, since its on RAID1 we can just replace a disk to rebuilt since it a mirror.. Can we do hotswap on this instance? also, is this the only reason that the server goes responsive frequently (which I cannot really think of since its a mirror).