what is the advantage of separating the ESXI OS from the Data?

[adotan]

Hi,

I would like to purchase a Server for my production.

should I set the server with 2 disks in Mirror for the ESXI OS and 3 disks in RAID 5 for the Data or I can just have all disks in Raid 5 (both the ESXI and the data)?

Thanks!

Dotan.

[Josh26]

Given that ESXi is perfectly capable (and supported) running on an 8GB USB drive or SD card, putting two SAS disks in a mirror just to install the Hypervisor is a very expensive option.

Still, I see many businesses choose to do it - usually just out of a "that's how we did it in Windows" type of fear.

[adotan]

I know...this is what I used to do when installing Windows Server. the question if it gives you a better performance or it's really waste of money....

[a_p_ · Accepted solution]

Definitely put all disks in a single RAID set for better performance. Once loaded, ESXi runs in memory and only writes logs and configuration data. The disk space required for ESXi - including a 4GB scratch partition - is ~5GB. In ESXi versions prior to 5.x it was a good idea to place ESXi on a separate disk in order to be able to reinstall the system, but with v5.x ESXi doesn't reformat the complete installation disk anymore.

Even if you still want to separate the OS from the data, you can still create a RAID set with all disks and - using the RAID controller - create logical volumes on this RAID set (e.g 10GB for ESXi).

André

[adotan]

Thank you for the answer!!