Can you use the HP Proliant ML115 G5 onboard RAID functionality with VMware ESXi 3.5 is a question that I have seen being asked for a while now. I thought I’d put this post together to answer this question for those of you that own an HP Proliant ML115 G5 and were considering buying that second hard disk to give it a try.
As you may be aware the HP ML115 G5 has four internal SATA disk connections (see below). All of which can be used in a RAID configuration (0,1,5) using the servers onboard RAID controller (MCP55).
To enable the RAID on your ML115 you’ll need to venture into the BIOS. After enabling the RAID you then choose which of the four SATA ports you want to include in the RAID set (and of course have hard disks attached to).
The four SATA ports are:
- Serial-ATA 0 Primary Channel
- Serial-ATA 0 Secondary Channel
- Serial-ATA 1 Primary Channel
- Serial-ATA 1 Secondary Channel
Before I start I should point out I am using ESXi 3.5 U4 which I am booting off a USB pen drive connected to the internal USB port.
Enabling and connecting up SATA disks to the Serial-ATA 0 and Serial-ATA 1 Primary Channels and then creating a mirror RAID set in the ’ROM-based setup utility’ presents two separate disks within ESXi (despite a mirror set out of the two disks being created).
Below: Both disks are presented to ESXi
When connecting the SATA disks to ports Serial-ATA 0 Primary and Secondary Channel and then creating a mirror set within ESXi only a single disk device is presented.
At this stage you may think that all is well with the world and that you now have a pair of mirrored SATA disks to create your VMFS volume on. Sorry to be the bearer of bad news but this is not the case.. I will demonstrate.
After creating a data store and copying a few test files up to it I then power down the server…
I remove the SATA cable to the Serial-ATA 0 Secondary port and start the ESXi server up again. Upon starting up the server complains that the RAID set is in a degraded state though, as expected, ESXi continues to boot off the USB pen drive.
Once ESXi has loaded and I connect to the host via the VMware Infrastructure Client (VIC) the data store containing the files I uploaded is still presented and fully accessible.
“This is looking good” I hear you say… though unfortunately when we power down the ESXi host, reconnect the SATA cable to the Serial-ATA 0 Secondary port, disconnect the Serial-ATA 0 Primary port and start the host again we get presented with the following message within the VIC:
As you can see from the message presented by ESXi it cannot see any persistent storage though it has detected some storage where a data store can be created (ie: the SATA disk connected to the secondary port). Although a mirrored RAID set was created using the onboard RAID controller this doesn’t translate to what is detected by ESXi.
So if you’re looking for a method of be able to use RAID in your ML115 G5 you may want to consider a RAID controller such as the HP Smart Array E200. I use one in a ML115’ for my home ESX(i) lab and run it using 4 x 250GB SATA disks in a RAID 1+0 configuration. I find performance more than acceptable running half a dozen VMs over it. They will cost almost the same as the server itself though you can pick one up for a little cheaper occasionally from EBay and the like.
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April 29th, 2009
Simon Seagrave
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My name is Simon Seagrave and I am a London (UK) based Senior Technology Consultant and vSpecialist working for EMC. 



Hi Si
Do you have benchmark on the HP e200 maybe hdtach result from a VM itself?
I have looked long and hard for a compatible RAID and have opted for an adaptec card on ebay.
Thanks
Erwin
Does the E200 support RAID over SATA HDs? I thought it was only for SAS HDs.
Is performance ok with SATA Hds?
Hi Victor,
Apologies for the delay in replying to your original query regarding the E200 controller. Just to confirm that the HP E200 does also support SATA disks though you do need to make sure you get the correct SATA cable for it. It will run SAS disks at 3Gb/s and SATA disks at 1.5Gb/s. I have a E200 controller in my HP ML110 G5 and have 4 x 250GB SATA disks connected to it in a RAID 1+0 configuration and find the performance just fine. That said it is only used in my ESX lab though I do have between 5-12 VMs (eg: DC, Exchange, SQL) running off of it at a time.
Hope this helps,
Si
I notice that ESXi 3.5 didn’t pick up the local SATA disk during install so the USB pen drive method had to be used but that this was fixed by ESX4i. Does the issue you document above with RAID sets created on the ML115 not working for ESXi 3.5 also still apply to ESX4i or has this been resolved too ?
Hi Jenkinso,
TBH – I haven’t tried it with ESX4i as yet. I still will check it out and will let you know.
Cheers, Si
Any chance to do that test? I’m considering setting up raid with the onboard controller myself and would like to see the above test done again with ESXi 4. thanks.
Hi,
Unfortuantely my ML115 G5 has been at my work for the past couple of week so I haven’t been able to test the RAID and ESX 4. I should have it back in the next couple of days and will test then.
Cheers, Si
Hi
I’ve just ordered my ML115 from Serversplus (thanks for the tip!) and am trying to work out the best setup. I’m interested in running ESXi but haven’t purchased a separate raid card mainly due to cost. There is a script http://www.virtualvcp.com/content/view/27/26/that allows the use of the onboard controller.
However i am worried that even though this appears to work, it doesn’t as per your post above. Have you had any experience using this or any other patch?
Thanks
Bob
Hi,
I picked up a couple of 1TB SATA drives today and tested RAID 0 and 1 configurations using both Serial-ATA 1 Primary and Secondary Channel and Serial-ATA 0 and Serial-ATA 1 Secondary Channels. Every combination ended up with a pair of disks being presented to ESX4i. It seems it’s still not possible to use the ML115 onboard RAID with this latest version of ESXi
I’d be interested for others to run the same tests as I’m new to the whole ESXi thing so may have missed a trick ?
Regards
Steven
Which cable did you use?
- HP 430479-B21
- Adaptec ACK-I-SASx4-4SATAx1 (2247600-R)
- Adaptec ACK-INT-SATA-FANOUT-1M (2167000-R)
- an other one?
Hi Egbert,
The answer is:
D) An other one: For the HP e200 array controller I use the HP 430762-001 SATA Cable. It has 4 x SATA connectors.
Hope this helps,
Si
Hi Steven, I’m having the same problem trying to create a raid 0 with esx 4i, all disks are seen as individual disks, have anyone got any furhter with this?
cheers
Paul.
Hi Paul,
I gave up and used a non-RAID config instead! Sorry.
Cheers.
Steven
Hi!
I want to make a note regarding this controller. If you experience very low write rate, it is happening because the default settings of SmartArray E200 disables drive’s write cache. This setting may be re-enabled with HP SmartArray management tools.
Correct, ESXi does not support any software RAID implementations.
The write performance will be horrid without hardware write caching enabled. ESX(i) must guarantee to the VM OS that a write is committed physically when the OS thinks it is, so performs no write caching itself.
Because of this a write of a single sector to a RAID-5 volume has a horrid penalty – read stripe, update block and parity, write stipe. Seems to end up at about 5MB/s tops.
The E200 needs the battery-backup unit installed to enable the write cache, enabling it without that is dangerous. Any interuption to power WILL corrupt the volume.
There is also a bug in early patch levels of ESXi 4 whereby even a clean shutdown doesn’t properly flush the controllers cache (PERC 5 is affected amoungst others), resulting in certain volume corruption even with a clean shutdwon of ESX!
Hope that helps.
this has been a great article… but there is more players in the market- Leno t2200 ( around £299 ) and it’ big brother IBM td200.
any chance you can put the m1015 serveraid card in the above machines to it’s paces and let us know if it’s worth keeping or we still need to invest in a different raid.
if you have a server, you got to have a raid.
thanks.
Hi Arif,
I would like to give a M1015 raid card a go – though unfortunately I don’t own one. Though if someone would like to load/donate one I’d be more than happy to write a peformance review around it.
Cheers,
Simon