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Looked through numerous answers around the varying RAID configurations and the best approach when dealing with ESXi. I still however have some outstanding questions.

There are 8x 300GB 10K SAS drives. This machine will house 5-7 VM's. As of now those would consist of 1 misc server, 2 db servers, 1 app server, 1 web server.

Based on research it would appear to simply go with 1 logical RAID 10 drive. This seems counterintuitive to the age old mantra of placing all your eggs in one basket and thus has me viewing it as a lackluster solution. I am unable to use a USB drive to host the OS (enterprise mandate); so the internal drives must be used. I really don't want too waste 2 drives on the OS either.

As of now my plan is:

  • 7x drives in a single RAID 10 setup

  • 1x drive as a spare

I'm looking to confirm my decision; in case something I am unaware of exists and would be a better route.

EDIT:

This will exist in a DL380G7 w/HP Smart Array P410i Controller FWIW.

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4 Answers

up vote 7 down vote accepted

I know those DL's and P-series controller very well and use ESXi 4.x myself.

Simply make a 8 disk RAID 10 array, carve off a ~10GB logical disk to boot from and assign the rest as a second logical disk.

That's the best solution from a mixed performance an reliability perspective - there's certainly no point having a hot spare to hand, you're just wasting two disks (R10 needs even numbers of disks), either buy a 9th cold spare or make sure you have a 4hr parts replacement support contract.

I wouldn't worry about the performance of the DB, 8 x 300GB 10krpm SAS disks is pretty quick and if you were really that bothered about DB speed you wouldn't be virtualising it at all right?

Basically don't worry, go for the easiest solution, it'll be fine.

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@ewwhite mentioned the ACU, would you agree with the single RAID 10 coupled with 2 logical drives configured via the ACU, one favor the host another for the VM's? –  Aaron McIver Mar 21 '11 at 18:35
    
That's what I'm saying, an 8 x 300GB R10 comes in less than ESX's 2TB/partition limit so just one array with a small boot/OS logicial drive and the rest for VMs. The benefit of this in the DL380 is that if you need a bit of space you can rip out the CD drive and fit another 8 disk cage then grow the R10 array 'live' and add a second 'extent' to your VMFS datastore, it's very fluid and easy. –  Chopper3 Mar 21 '11 at 18:40
    
Great, sounds good... –  Aaron McIver Mar 21 '11 at 18:42
    
This would be the approach I take. All eggs are in one basket yes, but then again, your Raid controller is always going to be a SPOF. You can always go with SAN, and multipath, etc, but this solution is what is commonly seen in the industry. –  slashdot Mar 22 '11 at 1:53
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See: Four disks - RAID 10 or two mirrored pairs?

But for HP, you also have the option of using all of the disks in one array, and separating the logical drives from the SmartStart Array Configuration utility. Carve a 36GB LUN for esxi and build logical drives for everything else you'll need.

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The ACU; is that accessible via POST? It seems that everything I see references it as a web based tool...for modification after the fact. Accurate? –  Aaron McIver Mar 21 '11 at 18:33
    
ACU is graphical, ORCA is the F9 on boot thing, for ESXi just boot from the SmartStart CD and use its built in ACU GUI ok. –  Chopper3 Mar 21 '11 at 18:38
    
The BIOS utility won't allow you to make these changes. You have to run it from the bootable Smart Start CD included with the server or available for download at: h20000.www2.hp.com/bizsupport/TechSupport/… –  ewwhite Mar 21 '11 at 18:38
    
Install is completed by a separate team...so I only see it as it is racked and ready to go. Thanks for the link! –  Aaron McIver Mar 21 '11 at 18:53
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I believe you need an even number of drives to make RAID 10 work, so either 8x drives in RAID 10 or 6x drives plus RAID1 OS/2x Spare

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Put em all into one big R10 array and be done with it. You'll be much happier with the administration overhead and your peak performance on any VM will be much higher. At least one hot spare is recommended, though. –  Hyppy Mar 21 '11 at 18:34
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Do any of your VM's have a particularly high i/o requirement? If not, you could go with a 7 drive RAID5 + spare.

The other option would be to build two RAID10 sets of four drives each, put one DB VM on each RAID10 volume and spread the misc server, app server, and web server wherever you feel is appropriate.

If i/o is not a real concern, then there's nothing wrong with going with a 6 disk RAID10 and two spares. The real egg to be concerned with is that you're running all of your VMs in a single server. Perhaps you should look at having two ESXi hosts and shared storage.

I would also recommend that you make sure to get the battery backup unit for the P410i. Your write speeds will be dramatically upgraded with the BBU.

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Given the OP has enough space for their VMs to fit into a R10 solution and this question is all about performance why would they go for a R5+HS solution? Also this is one controller with one path/bus, so having two 4 disk R10 arrays wouldn't increase performance but would increase the risk of data loss. And what would a 6 disk R10 + 2 hot spares achieve? I'd also go for the flash-backed cache over the battery-backed unit too, the BBUs are being phased out. –  Chopper3 Mar 21 '11 at 18:27
    
The machine was ordered with HP 512MB Flash Backed Write Cache –  Aaron McIver Mar 21 '11 at 18:38
    
Good call :) <extra characters> –  Chopper3 Mar 21 '11 at 18:42
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