ML115 & Hyper-V Disk Setup

[dandcg]

Need some advice regarding best way to setup the disks on a home server setup.

I’m planning on getting a ML115 Quad Core Opteron G5 and 8Gb ram to go in it, then to run Windows Server 2008 as the host with Hyper-V and file server roles enabled. The guest VM’s can then access the shares made available by the host.

My original plan was to buy 4 1Tb drives and run them on a RAID 5 array, partition a small section of for the host OS and then put the VHD’s on the other partition along with the data shares.

My problem is I have read the may be issues with disk bottleneck if I do it this way. Can anybody give me any pointers?

 

[TheLad]

I base my assumptions on my experience using VMWare Server, but I always want to have my host OS on a separate logical volume/disk set to the guests for exactly the point you make.

I found that when I used VMWare Server on a Windows 2003 Server host, I was getting disk bottlenecks on the host OS as well as the guests. When I put the guests on a separate logical volume, these issues disappeared.

I have never used Windows 2008 with Hyper-V but I would assume the same may apply?

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[PaulGillespie]

Have a few sites running Hyper-V, all have seperate disks for the Host OS and i run a SAS RAID 5 with 3 or 4 disks for the guests. These guests do not have disk intensive apps so it all works very well. If i was in your situation i'd configure my disks in a RAID 10. This will make the best of what you have but would not be great for a production environment. Since it's for a home build you can accept some performance drag.

 

[blister911]

dandcg,
SATA drives have the highest rate of failure. Best practices, and HP's recommendation, is to run them in a RAID ADG (RAID 6). However that will kill performance on any disk intensive applications. RAID 1+0 with a hot spare will give you better performance, but lower available space. (SATA drives are designed as "cheap" storage.)

Seeing that the ML115 only has 4 available non-hot plug drive slots and only supports RAID 0/1/5, your options are somewhat limited, unless you buy another controller.

 

[dandcg]

Right have decided to go down this route after some research... any views on this...

Raid 1 Set - 160Gb for the Host OS
Raid 1 Set - 250Gb for the Guest VHD's
Raid 5 Set (external controller) 3Tb for data.

Does anybody know whether the onboard controller in the ML115 can support two sets of raid 1?

Also am going to setup a fileserver vm with passthrough to the raid 5, so the host OS is minimum.

Dan

 

[PaulGillespie]

looks ok. Give it a go and see what it's like. You can always reconfigure the disks afterwards by exporting the VMs to a USB disk or something and the putting them back.

I've used ML 310s with the on board RAID and it has allowed me to set up 2 RAID 1s.

Judging disk setup is always harder with VMs as you just don't always know how much disk usage they require. assigning CPU and RAM is easy.