RAID level for ESXi 5.x

[virtualdive]

Hi All,

We are building up a ESXi host on a DL380p Gen8 with 2 x 146GB local disks. There is no SAN or any other type of storage available to support at the moment. So we are plannng to add 6 x 300GB additional local disks to the host to run the VMs.

I just wanted to check what RAID is best suggested for these disks?

thank you,

[tigerdeccan]

Really depends on your requirement , for non critical VMs I'd use RAID 5 , for critical VMs I'd use RAID 10 .  AS RAID 10 uses more disk just be aware of the number of disks required . In both the scenarios use on spare disk .

If you have some backup solution, then I recommend use 1 to 1 mirroring on esx install disk and then use RAID 5 with one spare disk for your VMs storage.

Hope this helps

[virtualdive]

Thanks Tiger,

The VMs are not so critical. So you think RAID 1 for ESXi installation disks (2 x 146) and RAID 5 for VM disks (6 x 300gb), is it? How about the space on the RAID 5? Will all the space be available for usage?

thanks again,

[JarryG · Accepted solution]

I'd say 2x146GB/raid1 for esxi is true overkill. First, you loose one half of disk capacity just because of raid1. Moreover, for esxi you need just a few GB. I'd say raid1 with two small CF-cards is just enough, but it is up to you...

Concerning raid5: very simple formula says:

available_disk_capacity = (number_of_disks_in_raid5 - 1)*size_of_the_smallest_disk

So in your case from 6x300GB/raid5 you would get ~1.5TB useful capacity (not including what you loose because of formating and partitioning, etc).

[tigerdeccan]

                       JarryG is right . But Im not sure HP DL380p supports dual SD cards for resiliance . If they do then we can go with this route .

please use this calculator for exact usage . Free RAID Calculator - Caclulate RAID Array Capacity and Fault Tolerance.

Thanks

mumzi

[TomHowarth]

personally I would install your ESXi instance on a flash card and use all available storage capability for VM's this could be set up as RAID 5

you could Mirror your Flash card, but not that many servers are capable of this.

just have another flash installed with the same server details for recovery. that is assuming that you are not using a vCenter server in your environment

[JarryG]

"...you could Mirror your Flash card, but not that many servers are capable of this..."

I had the same problem and solved it by buying two cheap CF-to-SATA adapters (eBay, each 5$). Then I attached 2xCF to raid-controller as "sata-drives", created raid1-array and installed esxi on it...