Esxi5 raid query

[-fedexer-]

Hi guys,

I'm about to setup my own home server using Esxi5 as the base, now the problem is I want to run my drives in raid for some redundancy, however I've been doing some reading and I know that you cannot use the motherboard raid as it counts as a software raid which Esxi doesn't support.

I cannot afford to go for a hardware raid option as it is currently too expensive, now I've been doing some reading and apparently it's possible to still use a software raid from inside the vm's, but with little detail as to how this is done other than set up each disk as a datastore and pass them to the vms?

Do i setup the drives as a datastore, pass them to the vms (i assume a datastore can be given to more than one vm?) and then come back out, into the bios and setup the raid there? Or must I use some software in each vm to create the raid, in which case how would I go about making sure the raid was the same for each vm?

As you can tell I'm a bit lost here, and new to virtualization, but want the ability to still have a raid for redundancy between my vms...

Hopefully someone can shed some light here in simplistic terms?

Cheers!

 

[Showboat]

You can combine disks in datastores to get extra space, but it's not raid.

If you set it up via the mobo process to get raid, does the install of esxi fail? Wouldn't have thought so myself.....Just because it's not supported doesn't mean it won't work!

Give it a go and let us know how you get on.

 

[-fedexer-]

I should add that my intention is to have a seperate disk from the raid where the OS etc will be stored.

I will need to test this tomorrow as I'm waiting for a delivery of equipment currently, this is pre-emptive to me trying the install, from what i've read there shouldn't be a problem with the raid being in-place during the install as esxi just sees the raid as seperate disks, but then what, would that still mean in the vms the raid is still solid but not in esxi?

 

[Uhtred]

What do you want to have stored on RAID, personal data, the VM base disks or both? I'm not sure if this is what you want but my solution is below.

VMs stored on a single datastore (single disk, no raid)

One of the VMs is Freenas and has 4 disks presented to it via RDM mappings

these 4 disks form a ZFS RAIDZ array (i can afford to lose one drive and I store backups of photos, documents etc)

Part of this array is shared via NFS. ESXi has this share mounted to it.

I then use ghettoVCB to backup the VM base disks from the original datastore to the NFS share.

This means that my VMs are better protected than if I had just a hardware RAID solution, but I have no speed benefits (not an issue for me as once the server is up there isn't much drive access)

 

[-fedexer-]

Uhtred, I'm assuming because you use DRM to pass them to Freenas that any other vm's on your server cannot access those drives nor that raid?

 

[Uhtred]

Uhtred, I'm assuming because you use DRM to pass them to Freenas that any other vm's on your server cannot access those drives nor that raid?

Correct, you can only present it to one vm but obviously Freenas can present the array via iscsi, windows share or nfs.

 

[Gammawolf]

What do you want to have stored on RAID, personal data, the VM base disks or both? I'm not sure if this is what you want but my solution is below.

VMs stored on a single datastore (single disk, no raid)

One of the VMs is Freenas and has 4 disks presented to it via RDM mappings

these 4 disks form a ZFS RAIDZ array (i can afford to lose one drive and I store backups of photos, documents etc)

Part of this array is shared via NFS. ESXi has this share mounted to it.

I then use ghettoVCB to backup the VM base disks from the original datastore to the NFS share.


This means that my VMs are better protected than if I had just a hardware RAID solution, but I have no speed benefits (not an issue for me as once the server is up there isn't much drive access)

Has this been stable for you? I'm assuming you had to hack the RDMs in if you're passing the individual SATA disks and not the controller via vt-d? Theoretically could you bring up that ZFS raid on a physical box with just freenas? I don't know exactly to what extent the RDMs leave the disks untouched by ESXi.. its a route i want to go down but i'm a bit wary about presenting the SATA disks via RDM if its not officially support for my home box (Yes i know my home box isn't officially supported either )

 

[Deleted member 138126]

Has this been stable for you? I'm assuming you had to hack the RDMs in if you're passing the individual SATA disks and not the controller via vt-d? Theoretically could you bring up that ZFS raid on a physical box with just freenas? I don't know exactly to what extent the RDMs leave the disks untouched by ESXi.. its a route i want to go down but i'm a bit wary about presenting the SATA disks via RDM if its not officially support for my home box (Yes i know my home box isn't officially supported either )

RDM devices are passed through completely untouched. You can take one and plug it physically into another box, and it will be recognised fully, or vice versa, e.g. take an NTFS drive from a physical Windows box, present it as an RDM to a Windows VM, and it will see the NTFS drive, same signatures, same everything.

 

[Gammawolf]

I wasn't sure if that was still the case with passing single SATA drives since ESXi doesn't support it, so you need to either pass the entire controller to a VM or there are various guides about hacking in RDM support for single SATA drives. Just wasn't sure if the RDM bit still fully applied since its been hacked to work

 

[Uhtred]

Has this been stable for you? I'm assuming you had to hack the RDMs in if you're passing the individual SATA disks and not the controller via vt-d? Theoretically could you bring up that ZFS raid on a physical box with just freenas? I don't know exactly to what extent the RDMs leave the disks untouched by ESXi.. its a route i want to go down but i'm a bit wary about presenting the SATA disks via RDM if its not officially support for my home box (Yes i know my home box isn't officially supported either )

No problems so far, i've replaced disks without issue and i've had no data errors and in theory I could plug the discs into a physical server without issue (although i've not tested this)

 

[Deleted member 138126]

I wasn't sure if that was still the case with passing single SATA drives since ESXi doesn't support it, so you need to either pass the entire controller to a VM or there are various guides about hacking in RDM support for single SATA drives. Just wasn't sure if the RDM bit still fully applied since its been hacked to work

It's only "hacked" in the sense that VMware doesn't allow you to do it through the GUI because it's not supported, but the end result technically is exactly the same to what we do on production SAN storage.

To be honest, I've heard enough chatter about issues with SATA and RDM that I wouldn't use it for any valuable data, just in case something did go pop.