Server Consolidation

  • Comments posted to this topic are about the content posted at http://www.sqlservercentral.com/columnists/sjones/serverconsolidation.asp

  • Good article!  I've done some server consolidations in the past.....some planned and others out of necessity but almost always with good results and happy customers. 

  • Good article Steve.  I'm in the process of determining if consolidation and or virtualization would benefit my company right now.  Good to know I'm heading in the right direction so far.

    Thanks.

    To help us help you read this[/url]For better help with performance problems please read this[/url]

  • Thanks Steve. On a related issue, I'm interested in your opinion re splitting your applications from your database server onto a seperate app server. I'm not thinking about web apps, but VB and COBOL apps.

    We're currently running on one server, and are considering splitting to a dedicated dev server and app server, but we will probably only have a non-dedicated 100MB network link between the two servers.


    When in doubt - test, test, test!

    Wayne

  • Much of the consolidation is driven by "accountants" who try to do the whole thing with SAN's and servers. Lots of stats about cpu unused, disks unused, so you get all your arrays as raid 5 carved into logical disks so that there's no "wasted" space.  fill up the disks, fill up the cpu's fill up the servers, one server with lots of instances, or virtual servers sharing resource of having resource shared and restricted.

    I have some sympathies, having had to endure 3rd party apps ( who are probably the worst offenders ) who make statements like " it has to be a dedicated server otherwise we won't support you"  oh and all the users have to be dbo or sysadmin - so you wouldn't want to consolidate anyway!

    It sort of makes some sense with 64bit especially but at the end of the day much of the consolidation is about providing hardware which is often vendor only supported - have you ever tried convincing anyone that a SAN is a performance bottleneck ? - there's lots of good things for them ( the vendors ) but maybe not for the dba.  200 databases still need managing regardless of them being on 5 or 50 servers -

    My experience is that often consolidation actually degrades performance, especially as the DBA's aren't normally consulted anyway and the "consultants" often know nothing about rdbms let alone sql server.

    [font="Comic Sans MS"]The GrumpyOldDBA[/font]
    www.grumpyolddba.co.uk
    http://sqlblogcasts.com/blogs/grumpyolddba/

  • Hi Steve Jones,

    Great article , I really enjoyed reading it. I like your business saving ideas on consolidation of servers

     

     

    thanks

    sri

     

  • It makes sense to consolidate, especially in the light of service hardening, such as clustering or mirroring technology.  It's expensive, but can be better justified by hardening several instances prone to outage.

    Charley Jones
    A+, ITIL, MCAD, MCDBA, MCITP: Sql Server 2005 Adminstration, MCT,
    MCTS: Sql Server 2005, MCP, MCSA, MCSE, MOUS, PMP
    President and Founder S3oLV.Com: Sql Server Society of Las Vegas
    President and Founder LVXUG.Com: Las Vegas XNA Users Group

  • An option that needs to be explored is using VMs such as either MS Virtual Server or VMWare.  This would go a long way towards ameliorating the concerns in the article with regards to patches required for one app conflicting with another.  Other miscellaney software issues that can crop up only affect one VM at a time.  VMWare long ago passed the point where it just runs along smoothly without problems in itself so as long as the host server is of sufficient enterprise quality and isn't pulling other duty.  The host system's downtime is a very rare occurance.  I've used multiple SQL servers on VMs within a well equipped, quality host server and it works quite well as long as the time is taken to properly allocate the resources for the individual VMs via the host VM management.  Overselling the CPUs for example (such as 8 VMs each allowed to use 2 CPUs each in an 8 way) functions well under light loads but leads to performance issues when all are used heavily enough that the VMs fight for time on the real CPUs.  But the same server with only 4 VMs allowed to use 2 CPUs each could run at reasonably high loads.  The same applies to disks, RAM, etc, etc, but you get the idea.

    The problem with this idea is that it eliminates the cost savings in software licensing for the OS and SQL Server as each VM needs its own license.  But in hardware the savings are still considerable.  Also, such licenses as backup software are still able to be consolidated.  You only need one backup license to be run on the host OS.  Its also easier to manage only one host physical server sitting in the rack even though there is still the same level of software management of the individual servers within the VMs.

    Anyway, just my 2 cents on the consolidation issue.  Your mileage may vary.

  • Good article Steve. We've been doing some consioldation on to active/passive clusters. One cluster presently has 20+ applications on it. Yes, there are notification and maintenance headaches associated with this consolidation architecture just as detailed in the article. So now we are exploring a slightly different take. Using almost the same consolodation, but with multiple instances on the cluster - thusd enabling us to separate the applications again. This should afford us the maintenance flexibilty we had when we had many database servers. It also addresses the issue of those rogue applciations that needed 'sa' or 'sysadmin' role - which under the single instance cluster, prevented us from further server consoldation unless we wanted to put others at risk. So far out research only seems to be impacted by the SQL2K limit of 16 named instances per cluster.

    RegardsRudy KomacsarSenior Database Administrator"Ave Caesar! - Morituri te salutamus."

  • Thanks for the comments. As far as separating DB from Web, we've done it here and I tend to recommend it so the OS doesn't have two apps fighting for memory more than anything. CPU as well, but with SQL, it doesn't want to give up memory.

    I'm not sold on consolidation in smaller environments, but as you grow into tens or 100s of servers, I've got two words for you: Power and heat. They might make you rethink consolidation.

  • Hi Steve,

    I am in the process of putting together a plan to consolidate 60+ servers onto a clustered environment...should be interesting!

    I enjoyed your article and am looking forward to hearing about the technical side of consolidating in a future article.

    -John

Viewing 11 posts - 1 through 10 (of 10 total)

You must be logged in to reply to this topic. Login to reply