This might be obvious, but when attempting to estimate the number of servers you can load on a Z10 - keep in mind that a z10 EC is aprroximately 40% faster than a z10 BC.
On Mon, Dec 6, 2010 at 9:42 PM, Tom Duerbusch <[email protected]>wrote: > I will shot gun some of them... > > 1. Disaster recover is much easier on the mainframe. In effect, no matter > what hardware is replaced with what hardware, it is all the same. With PC > type servers, the hardware, hence the software drivers are constantly > changing. This may force you to reinstall the software instead of just > restoring. > > 2. Our I/O subsystem. Mainframes with ficon/FCP, can drive (per IBM > documentation) drive hundreds of thousands of I/Os per second. If you only > need a few hundred I/Os per second, well, that is within PC ranges. > > 3. Licensing is a two edge sword. Putting 5 copies of Oracle on an > IFL...you only pay for one copy. However, if you have many, one copy > products, you end up needing more engines on the IFL, which (if you get > charged by the engine), causes those product charges to increase. > > 4. Disk is disk. It costs the same whether your DS8100/DS6800 is > configured for CKD or SCSI disk. > > 5. Mainframe memory is more expensive, but it is more effectively used. > When an application states that it needs 4 GB to run, I start around 500 MB > and increase it when needed. > > 6. When a server application needs more resources, many times you have to > go out and buy a newer, bigger server. When a mainframe server needs more > resources, you may have options to rob other servers. Also for larger > shops, Capacity on Demand. > > 7. Green. There is an application on z10s and above, that will show you > your footprint and the incremental footprint for additional loads. I seem > to recall something about you can plug in data from servers you are > migrating from, to show the incremental decrease in the footprint of the > datacenter. There hasn't been much chatter about this on the listservs so I > don't know how well this has been received. > > 8. Internal network speed. If a function requires the use of several > servers and they are network attached, things are slowed up by the network. > No such problem with Hypersockets or Guest Lans/VSWITCH (under VM) and can > have large packets also. > > 9. We don't, but we should have performance tools. You buy one for the > LPAR and you know what is going on. Rather than buy one per server. You > still might need specialized performance tools on some servers. Oracle OEM > to measure internal Oracle performance, for example. > > 10. The serious problem with PC servers is context switching. There a > dog. Mainframes are great at this, as CICS transactions really drive this. > If your load tends towards transactional instead of batch (data mining), PC > type servers were not designed for this. I assume that RS6000 and Sun type > servers are pretty good at context switching, but I have no direct knowledge > of this. > > > Back when Linux started hitting mainframes and IFLs were announced, there > was discussions of 100 images per engine. A lot of the servers at that > time were routers, DNS, Samba, NFS and some web. Now I seem to here 10-20 > real workloads per engine. > > BTW, there was/is an MES upgrade from one box to another. In the case of > the MES upgrade from a z/890 (our box) to a z10 (hopefully/maybe ours), the > license for the IFLs transfers. Which means that we would not have to pay > for the Linux side again. And the new IFLs are faster per engine than the > older IFLs. That is no longer a cost on the mainframe that you still have > on the other server platforms. > > Know that I think of it, I may be thinking of the MES upgrade that pulled > cards (and you license and CPUID) from one box and installed it on the newer > box. I'm now thinking that the IFL engine transfer will happen with any > upgrade to a new box. I've been looking at the MES upgrade option for so > long, that I have MES on the mind <G>. > > Tom Duerbusch > THD Consulting > > > > >>> John Cousins <[email protected]> 12/6/2010 11:07 AM >>> > Here we go again! > Without success, we've been trying to get the IT department here to adopt > z/Linux since 2003! > > Our zVM licence has been recently cancelled, and I have just had a request > from our Enterprise Architects for some costing for z/Linux as they need to > compare server virtualisation costs with VMware! > > One problem of trying to get a cost per virtual server was always trying to > estimate how many servers an IFL will support. We had a 13 SuSe servers > defined in a z800 IFL but as they were hardly used we couldn't measure a > thing! > > So are there any rules of thumb out there on how many production virtual > servers would run on a Z10 IFL? Obviously it will depend on server > utilisation, guess that will need to be estimated as well? > > Another question is where do the bulk of the savings come from? From my > investigations over the years other success stories suggest most savings > come from software licensing, e.g Oracle, Tivoli etc. but also from > networking infra-structure by the use of virtual switches. Are there any > other areas that provide benefits? > > Any ideas or constructive suggestions would be gratefully received! > > Best regards > > John > > > > John Cousins > Senior IT Officer > Central Support Services ICT Division > Bristol City Council > Romney House > Romney Avenue > PO Box 1380 > Bristol BS7 9TB > > Tel : 0117 922 4705 > Fax: 0117 922 3983 > e-mail: [email protected] > > ______________________________________________________________________ > 'Do it online' with our growing range of online services - > http://www.bristol.gov.uk/services > > Sign-up for our email bulletin giving news, have-your-say and event > information at: http://www.bristol.gov.uk/newsdirect > > View webcasts of Council meetings at http://www.bristol.gov.uk/webcast > > Bristol is the UK's first Cycling City. Visit www.betterbybike.info to > join thousands of others getting around by bike. > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > > -- Mike Shorkend [email protected] www.shorkend.com Tel: +972524208743 Fax: +97239772196 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
