jmay
Enthusiast
Enthusiast

RAID internal drives in Xserve possible when using ESXi 5.1?

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Does anyone know if there's any way to RAID the internal drives on an Xserve 3,1 when running it as an ESXi 5.1 host?

I'm looking to do a mirrored raid for redundancy.  Ideally, software RAID would be great, but I'm willing to use a hardware RAID card too, if that's what it takes.  Sounds like the Apple RAID card for the Xserve is not supported.

Thanks for any suggestions!

- John

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mcowger
Immortal
Immortal

Then yeah, with no ability to do a supported card, and no ability to do software RAID (ESXi doesn't do that), then you are mostly outof options unless you do some hackery like giving the drives directly to a VM (not technically supported with SATA drives, but possible), using software RAID in the VM and then loopback mounting that from ESXi.

--Matt VCDX #52 blog.cowger.us

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a_p_
Leadership
Leadership

ESXi does not support software RAID, but requires a supported hardware RAID controller (see VMware Compatibility Guide). If this is a production host, make sure the RAID controller has battery or flash backed write cache (BBU/BBWC/FBWC) to allow for write-back operation. This greatly improves disk performance.

André

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jmay
Enthusiast
Enthusiast

I don't think it's possible to use a 3rd party RAID card in the Xserve, as the drives connect directly to the backplane and there are no SATA cables.

That said, since the Apple RAID card isn't supported (not listed on the HCL and I've done a real-world test), is there truly no way to RAID the internal drives?

- John

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mcowger
Immortal
Immortal

Then yeah, with no ability to do a supported card, and no ability to do software RAID (ESXi doesn't do that), then you are mostly outof options unless you do some hackery like giving the drives directly to a VM (not technically supported with SATA drives, but possible), using software RAID in the VM and then loopback mounting that from ESXi.

--Matt VCDX #52 blog.cowger.us

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frederikvdr
Contributor
Contributor

What about external storage through FireWire, thunderbolt, ... which is then a raid DAS Anyone tried this?

Another method is an iSCSI LUN from an external storage box to the second ethernet card. (Or add more ethernet cards through a third party ethernet card)

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JayceFFTir
Contributor
Contributor

jmay a écrit:

I don't think it's possible to use a 3rd party RAID card in the Xserve, as the drives connect directly to the backplane and there are no SATA cables.

That said, since the Apple RAID card isn't supported (not listed on the HCL and I've done a real-world test), is there truly no way to RAID the internal drives?

- John

Do i understand well that you still can use the drives of the XServe without removing the RAID card IF you don't RAID them ?

I thought you couldn't even access them if you keep the RAID card.

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jmay
Enthusiast
Enthusiast

I believe you are correct that drives connected to the RAID card won't work at all.  We replaced all RAID cards with the stock backplanes in our ESXi boxes.

- John

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JayceFFTir
Contributor
Contributor

I am in the process of migrating 3 XServe to ESXi, 2 of them are one, the 3rd one has a RAID card and i didn't started to look at it yet. That's why i was confused. I'm pretty sure this didn't change with ESXi 6 Smiley Sad...

Well, i guess i will have to order a backplane too Smiley Happy

Thanks

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ryandesign
Contributor
Contributor

Can you please elaborate on this "hackery"? How do I "give the drives directly to a VM"? I have looked in /dev/disks and they are (unsurprisingly) not there; only the SSD is there. I would love to be able to attach the Xserve RAID card and its attached drives to a single OS X guest VM, but I don't know how to do that.

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ibgb
Contributor
Contributor

If the xserve motherboard chips support pci passthrough, you can just pass the raid card through to the mac os. I know the xserve uses a few intel chips on their motherboard, but I don't know if the chipset does support pci passthrough.

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ryandesign
Contributor
Contributor

I am not familiar with "PCI passthrough" but I presume it refers to PCI cards. The Apple RAID "card" in the Xserve is not a PCI card; it is a replacement drive interconnect backplane. Under OS X, in System Profiler, it does not show up in the PCI section; it shows up in the Hardware RAID section, with no further information given about the manner in which it communicates with the computer. If the Apple RAID card does happen to communicate using the PCI interface, and if the Xserve does support PCI passthrough, how would I "just pass the raid card through to the mac os" as you suggest? What would I click, what commands would I enter?

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ibgb
Contributor
Contributor

Some boards support virtualization features. Pci passthru enables esxi to pass interrupts etc. from devices on the pci buss directly to a VM, so the VM sees the hardware as if it was running natively--not some virtualized device.

The raid is probably on the pci bus, but the board may not support the virtualization features.

You would google vmware pci passthru, and the windows exe client can set pci passthru up.

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ryandesign
Contributor
Contributor

You were right, in vSphere Client > host > Configuration > Advanced Settings > Edit, the RAID controller did appear, and I could enable passthrough on it, reboot the host, and then assign it to a guest, and the guest does see it and the drives attached to it. This is with ESXi 5.5.0U2. I followed primarily these instructions‌‌. Now that I know this works, I can afford to buy the larger 2TB drives and a new RAID cache battery. Thank you very much for your help.

Screen Shot 2016-01-15 at 8.27.10 AM.pngScreen Shot 2016-01-15 at 8.29.47 AM.pngScreen Shot 2016-01-15 at 8.55.46 AM.png

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ibgb
Contributor
Contributor

You may want to test it ! I am sure it may not be on the approved list of hardware, but if they are intel chips on the pci bus it may be ok. Especially with errors or heavy loads.

You may want to change the correct answer for future google searches too.

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ryandesign
Contributor
Contributor

Looks like the first problem with this configuration is that it only works the first time the guest is booted. If the guest is restarted, the RAID card disappears. The only way I found to make it reappear was to restart the host. So that's not ideal.

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