Virtualisation and other stories
You've probably seen some of my previous posts on the virtualisation thread. Here's an update on where we are and what we are going in the virtual world. I hope it's of some use to you.
Background to recent changes at the chalk face
The move to Windows 7, Office 2010 and IE9 has been an interesting one, throwing up all manner of issues we would not have even considered possible just a few weeks ago. All seem to be resolved apart from an Impero issue with internet blocking (or not) and multiple tab opening and SIMS not working well with Office 2010 (there's a suprise). System Centre works a lot better with Windows 7 machines. We thought MAK activation might be an issue (we decided to use this in favour of KMS can't remember why) but ended up being easy. Sharepoint 2010, Exchange 2010 Lync 2010 all working nicely. In fact everything seems to be OK. Was this a good move? Yes I think so, no more OS or Office moves for another 7 or 8 years. I'll be long gone by then!
What's all this got to do with virtualisation? Quite a lot as it's the front that drives the rear (if you'll excuse the double entendre). That and the growing and ever changing needs of the staff and students. The school's reliance on school hosted services, therefore, (our decisions as other solutions we unreliable and inflexible) makes the SAN and ESX host decisions critial.
Times are hard and money short even for academies. Two of our ESX's and the primary SAN are up for renewal in April next year after 5 years of perfect service. This time I'm going for simplicity. As the IBM kit we have is so reliable, I am moving to just 3 ESXs each with 48Gb memory, consolidating to a single SAN (rather than 2/3) and removing the SAN switch. I will, however, be using one of out older SAN switches to add our backup solution, Veeam, but the ESXs will access the SAN directly. Why are we reducing to 3 ESXs? We already run 40+ virtual servers and I cannot envisage us expanding much more over the next 5 years other that file, mail and intranet services which rely on storage capacity rather than ESX memory. I defy anyone to show me a school in the UK that needs more than this!
The choice of server is a no brainer... IBM x3650 M3. Good reliable service - worth every penny. We will be buying with 5 years warranty which, to be honest, we have only ever used once on a faulty CD drive 6 months after purchase. You can probably get faster but I'll go for the reliability every time. We expect to pay about £7,500 per unit (£1,400 pa)
The choice of SAN, though, is a little more difficult. I have been interested in the new technologies around at the moment, in particular Tintri (a demonstration of which we are going to next month) offering a 4U box with 12Tb made up of SSDs and SATA. The claimed IOPs are impressive, I only hope the price and reliability are equally impressive. Our storage requirements, unfortunately, are large and a single Tintri unit would only just be big enough for what we have now so we would have to consider buying 2 units. This, I think, will put the solution beyond our means. The replacement for our IBM DS3400 will probably be the IBM DS3512 wich has more capacity (supports 96 drives) and more cache. We will probably buy the unit with 4 expansion trays (populating only 3 of these fully with 600Gb 15K SAS drives in the first place) and turbo performance. I did look at remote mirroring but to implement that would cost in the region of £13,000 (including the hardware) not cost effective given our SLA. I expect to pay no more than £35,000 for the SAN. Which works out at around £7,000 per year, interestingly that is 4 x less than we pay per annum for our internet connection (yet another story soon to be resolved)! It's a hell of a lot more reliable and delivers a damn site more services!
The total cost of maintaining the SAN + 3 ESXs is therefore £11,400 pa. Not a huge amount in the scheme of things.
Whatever direction we take in the storage arena our rack space rather than decreasing, is actually increasing as we consolidate more of the physical kit.