Virtualisation of Servers

[camel]

Thats the beauty of virtualisation, you can build it in stages.

 

There is absolutely no need to do everything all in one go.

 

This is so true. I started out with a single HP DL380 G6 with local storage, setup Hyper-V and virtualised some of my servers. Over time I purchased a second DL380of similar spec and virtualised the rest of the servers. Recently purchased a beast, readynas 4200 with the 10Gb SFP+ option, which will be connecting servers connected to shared storage each with 2x10Gb links in the summer. It will have taken about 2 years with obtaining the funding, planning and staggering the whole process but it has been really enjoyable and a great learning experience.

[dhicks]

It would be possible to do a system on the cheap by running several VM's on a single host's internal storage, but you would loose the ability to migrate them instantly on hardware failure (or maintenance).

 

No, you can simply mirror storage volumes between servers - you avoid having the SAN as a single point of failure, you avoid the cost of buying a SAN in the first place and you have proper hardware reduandancy in case of failure (fire, flood, etc).

[SYNACK]

Why pay for support? its the whole point behind linux. If you need an answer its on the internet!

 

Oh you mean, 'read the man pages noob' or 'just fix it yourself' or we'll look into that bug when we have time of another thousand users report it? I like my support a little more supportive personally.

[garethEds]

So much to think about. So much in the air. SO many conflicting pieces of advice.

 

GJE

[denon101]

I have just completed my virtualisation project. We run a 2 node cluster with a SAN for now with a third machine connected to san for backup. As we run VMWare 5 and VCentre and I found that I could not get my LTO5 picked up on VMWare. So that is physical running Backup Exec and then the virtual agents are installed on each VM. The hardware is 2 Dell T410's with 32GB ram and 2.4 XEON processors and a HP P2000 storageworks SAN with a single controller with 3TB storage ( this is enough for now as we are only a Middle School ) On this we have everything virtualised and we are running 11 VM's and thus far everything is running fine..... Probably put the death curse on it now!!!

[truebluesteve]

We started out getting our SAN a couple of years ago to increase the storage across our user servers which were rapidly filling up, and which were also quite old and needed replacing. We knew that we would virtualise at some point too, so the SAN made sense.

 

We did the virtualisation last year and we have the following setup -

 

1 x EMC CX4 SAN

3 x SAN Hosts (32GB Ram Dual 6-Core Processors)

VMWare ESXi

12 x Virtual Servers

 

Our FRDC and Exchange servers are still physical at the moment as they are fairly new and still under their hardware warranty. Once that runs out, they will be turned into VMs too.

 

Our experience has been really positive and the system is really easy to use. My big concern was for the performance of the SIMs server, but its never been an issue.

 

I cant speak about the other flavours of Virtualisation software, but VMWare has worked perfectly for us.

 

Steve

[m25man]

Been a Hyper-v fan myself as on a school license 3node clustering and SCVMM integration is about as cheap as it gets.

Shared storage makes it easy to move VM's from host to host be it a CSV or a mountable LUN individual servers with local storage for VMs is fine for a bunch of application servers but storage that can be re-assigned on the fly between hosts has clear advantages.

That being the case it doesn't have to be £30k's worth of Equallogic or Lefthand....

 

In our experience of cheap SANs they have all performed well and been highly resilient however as volumes get larger the challenge of backups, snapshots & recovery get more and more complex.

This normally results in what should be a simple Virtualization project into a complex and sometimes costly excersise to provide the 24/7/365 expectations of the SMT to whom once you start evangelising about your new virtual server farm will expect if not demand it!

 

Without total duplication of hardware and storage this type of enterprise uptime target is impossible to guarantee on a tight budget, but Windows Server 8 and Hyper-V 3 look set to change this completely.

 

Hyper-V Replica: New VM replication tool for cost-conscious IT shops

 

If I were starting from scratch I would certainly recommend taking a close look at what Hyper-V 3 is shortly to bring to the Virtual circus, storing and running VMs over SMB shares, live VM replication, NFS support, all features that on paper at least levels the playing field and will eliminate many of the challenges currently encountered when trying to achieve utopia on a budget of £2.50 per user....

[localzuk]

I'm currently waiting on confirmation of a virtualisation project at our campus - but rather than buying a pile of new stuff, this is a 'mid-way' project. We have a DAS array already, which I intend to utilise by replacing the controller card for a newer model to achieve RAID 6, then upgrade 3 relatively new Dell R610s (the old provider put 4GB RAM and 1 CPU in each) to have dual quad core CPUs and 32GB RAM each, stick Windows Storage Server 2008 R2 on one of the older machines to run the DAS (with its deduplication built in), and move things on to that set up using Hyper-V.

 

Total cost is about £4k.

 

Then, in a few years time when the DAS should be replaced, it will be replaced with at least 1, probably 2 SANs.

 

There is no need to do everything at once - doing so is very costly.

[owen1978]

Virtualization is actually very easy.

 

Just install a new Windows 2008 R2 server with the hyper-v role. Start building new servers machines as and when you need them. You can even migrate a current server using a small utility like disk2vhd.

 

The advantages are:

 

- Quick to build new servers

- Less hardware needed

- Ability to backup/image any server in a few minutes

- Easily migrate servers to new hardware or keep copies of servers on redundant hardware

 

People who use Sans or specialist switches are taking virtualization to the extremes. You normally find that type of thing in big hosting companies or large companies. It works fine in schools but its a bit overkill imo. A simple server with a 500gb hard disk is enough for 5 or 6 virtual machines in my experience.

 

Do you think so? I have been thinking the same i was just looking into getting a High Spec HP Server & a reliable NAS (use enterprise sata drives in NAS btw)

 

SERVER

HP ProLiant DL165 G7 Server series Small & Medium Business

 

NAS

RNRX4420

 

We just are small primary i think getting SANs would be overkill, maybe get a extra NAS to replicate

Any thoughts anyone?

 

EDIT:

Eventually we are hopefully going down the RDS route so would a SAN then be necessary?

Edited March 7, 2012 by owen1978

[zag]

SANS are designed for large scale storage in data centers really...

 

Why even bother with centralized storage? We just use the internal disk of the server.

 

Virtulization lets you take images of your servers to your hearts content so there is no need to really worry about downtime of a disk if you have a regular backup strategy.

 

EDIT: I specked up a Dell 1u server with the fastest Xeon chip and 24gb of ram for under a grand the other day. Can't say fairer than that

Edited March 7, 2012 by zag

[gpe5732]

We have virtualized, I believe 55 servers, or 56. I can't remember. By the end of next year we will have nearly 100 virtualized. As others have said, backups are a breeze, failover is simple. We have no downtime on our systems that are virtualized because they failover to another running server with no issue.

 

The biggest selling point for us has been the actual dollars saved by virtualizing our environment. We're nowhere near fully virtualized, but we're getting there. We've used Hyper-V to create our own cloud in our data center. The actual monetary value we save each year makes this investment more than worth it.