Virtualising SQL Server

[robknowles]

Hello,

Currently I have virtualised several servers onto 3 VMWare ESX Servers - Exchange, KS3 Test Stuff, ALAN Software, Printers and all sorts. The only servers not virtualised are my 2 DC's, 2 x File Servers, Backup Server, ISA Server and SQL Server.

My question is that has anyone virtualised their SQL Server (MS-SQL in my case) and if so is perfomance still acceptable? Currently the SQL server uses lots of RAM (well over 10GB) but not much processing power - the only time it normal peaks is when I run an SIMS upgrade. Since the physical server is a Quad Core with 32GB Ram I could install ESX on this and the virtualise the SQL Environment and then have plenty of space for other apps as well. What do people think?

Also does anyone run virtual DC's, or an entirely virtual server infrastructure?

Thanks,

Rob

[dhicks]

Also does anyone run virtual DC's, or an entirely virtual server infrastructure?

I'm aiming for a completely virtual infrastructure, yes - I have a virtual DC, although admittedly it won't be put under any use until the pupils turn up again. We've discussed virtaulising DCs here before - it's advised against by Microsoft at the moment, but I think that's only because doing a snapshot restore of a DC in a multiple-DC environment would confuse things, as far as I could figure out my single-DC setup should be just fine.

I think we've discussed virtualising SQL server before, too. I think we talked about how it would probably be a good idea to give SQL server its own harddisk (or, more likely, RAID array) to use, as (as you've observed) SQL server's performance doesn't have much to do with processor speed but will probably depend more on disk performance.


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David Hicks

[ranj]

as far as I could figure out my single-DC setup should be just fine
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David Hicks

Gosh thats a bit of a Risk, A single DC setup! What happens if it fails!

[Theblacksheep]

Various VM docs and tech blogs say virtulising the SQL server is fine. As dhicks says tho the database should go on its own specific Lun or array with fast SAS disks.

[Ric_]

An update... I virtualised my SIMS server (MS SQL) onto XenServer at Christmas. Since then the performance has been more than acceptable - it's quicker than the old piece of rubbish it was on!

I suppose the first big test will be the next upgrade. I haven't given it masses of resources yet though - and plenty of room for expansion.

Since my summer migration, my two virtualised DCs have worked fine. I've even live migrated between hosts without issue... AFAIK you just shouldn't snapshot them.

[dhicks]

Gosh thats a bit of a Risk, A single DC setup! What happens if it fails!

Then its DRBD mirror would take over.

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David Hicks

[DrPerceptron]

We virtualised nearly our whole system into a Dell M1000e Blade Centre... bar DC's (they didn't like the P2V converter for some reason)

Dell recommended that we use a dedicated blade in the centre purely for a DC, so, we have one to complement the two that should be virtual - it might come that we rebuild those two from scratch, who knows... (the newest is the master)

We've got two entirely different SQL boxes virtualised, one for Eclipse (Librarian wouldn't shut up complaining it was even slower when shared with sims) and one for Sims, both run a lot happier in the virtual environment than they did physically (Sims's used to SAS drives before and still does)

If you're going to virtualise a lot, you could look at VMotion, it's quite active over our 3 ESX servers...

so on ours, we've got FMS, Sims, Eclipse, WDS, CCTV, EPO, Ubuntu, Exchange 2003 and R2 Print

[robknowles]

Hello,

In the end I did virtualise the SQL Server last October Half-Term. I've never noticed any performance loss and nobody has ever mentioned to me about slowness, nor have I had any issues with SIMS Upgrades or anything else for that matter.

Thanks,

Rob

[Michael]

SQL Server 2008 Virtualisation which may interest you

[fiza]

i know this is an old thread but;

RobKnowles - I want to do the same and virtualise my SQL Server which is used purely for SIMs. Did you have to do anything special? Or did you just run the Convertor on the live system?

Any advice would be appreciated.

[Theblacksheep]

We've VM'd SIMS&FMS, exchange, the vcenter (SQL)... all file servers (still running CC3 along with starting new network), fog, service desk and VM DCs.


Sims only has 4GB of ram and 2vCPUs, it runs fine (1700 children, 150+ teachers)...

Exchange runs much, much better.

vCenter hardly does any SQLing so use is minimal.




@Fiza: Shutdown SQL database first. Don't run that live, but the system can be on it can be done with converter and not the cold-converter.

[wagnerk]

If you're running Windows 2008 with Hyper-V, try out the SCVMM program. We've using it and find it to be a very good piece of kit, the P2V convertor is excellent (one of the features that is excellent is letting you re-size the HDD's) and we've virtualised quite a few servers already with it, including a live Sims server.

-Ken

[robknowles]

Hello,

@fiza; I shutdown down the host and then booted from the VMware Convertor CD (version 3 when I used it, but it's now on Version 4 - which I haven't tried) for a 'cold' migration. Doing the migration this way ensured that the database and everything was fine, which it was.

Thanks,

Rob

[AdrianSpencer]

We have now reached the capacity for rack space, UPS and Airco and are investigating virtualisation of as many systems as we can. We have taken advice and the consultant has been running monitoring on all servers. The results of this suggests that it is not a good idea to virtualise our SQL cluster. We do also run Sharepoint MOSS2007 databases on this cluster along with SIMS and a number other management and MIS databases. So, we will be building a new physical SQL 2008 Cluster to host these.

SIMS:
However, I am very interested in the comments about SIMS on Hyper-V posted here. With the high level of maintenance it requires, the fact that it has to have part of its application tier on the SQL box itself, and its requirements for file locations (more in a bit). I am looking at moving this to its own virtual server.

I have found that SIMS is not particularly happy living on a cluster (not cluster aware). When upgrading I have to do registry updates to the second cluster node. I have never known failover to just work for SIMS without some intervention. My other databases failover fine. In an ideal world it is good to separate logs from datafiles. Not in SIMS. Their DBAttach utility and System Manager application (more application installations on my database server) seem to require that the log files are in the same location as the data files.

So, now we move SIMS to Hyper-V. Not such a simple process as SIMS is our main MIS system and feeds data into nearly all of the others (Sharepoint, finance, transport and more) as well as into AD. Digging this lot out and re-establishing all the connection strings etc it going to be fun.

SHAREPOINT
It may be of interest to those using MOSS2007 that the results of our monitoring suggest that we should virtualise the two Front-end Web servers, but not the index server as disk IO is high.


OTHER ROLES
Out of 46 physical servers we reckon that virtualisation will have no negative (and possibly positive)
impact on performance for 20 of these. NB these are not 20 server roles as we have a fair bit of clustering.

Adrian

"One hundred idiots make idiotic plans and carry them out. All but one justly fail. The hundredth idiot, whose plan succeeded through pure luck, is immediately convinced he's a genius." Iain M Banks