Thursday, October 27, 2011

Beginners Guide to Copenhagen Train System

I attended VMworld Europe last week, in Copenhagen, Denmark and had a great time.  Part of this was using the excellent system of trains to get around.  In the process I learned a few key insights that I wanted to share for others that might be using the trains in Copenhagen for the first time.  If others reading this are more knowledgeable please add comments (or if you find errors let me know about that too).

There are actually three different types of trains that operate in Copenhagen.  If you get a city pass, you can ride any of them while remaining in the Copenhagen area.  The three train types are the Metro, S-Train, and Regional Trains.  The Metro is run by a different company than the S-Train and regional trains, and hence they have separate websites.

The Metro currently has two lines - M1 and M2 - which both share Vanlose as the end of the line to the west, but diverge at the Christianshaven stop to end at Vestamager for M1 and Lufthavnen for M2.

The S-Train (or S-Tog in Danish) is the other commuter train system in Copenhagen.  It has what appears to be at least seven different lines, that are color coded.  There is a big "S" sign that marks which platforms are for the S-Train.

The regional trains go to areas beyond Copenhagen and is what you take to go over into Sweden or up to Helsingor for example.  This is also what I rode from the Airport to the Kobenhaven H station, and later from Kobenhaven H to Malmo C station in Sweden.

This map is the best one I found. It shows all three trains and stations.  It's from a travel blog site.  I think that it is the best because the Metro is run by a different company than the S-Tog and regional trains.  So it took an independent 3rd party to put everything together.

You can transfer between the different train types, you just need to make sure you have the proper ticket.  They do check people for tickets and they do hand out fines to people that do not have a ticket - I saw this happen twice in the week I was in Copenhagen.

There were always very helpful people in the ticket offices and on the platforms, at the big stations, that were happy to help me understand which platform and which train to take.  It was also very nice that they all spoke English.  If you aren't sure what you are doing - just ask somebody.


Wednesday, October 19, 2011

Taking a Different Look at Performance for vSphere Storage Appliance

I've been working with and doing performance testing with the new vSphere Storage Appliance (VSA) for most of this year.  The white paper was published last week and I encourage you to read it if you are interested in getting a deeper understanding of VSA.

I've also done a lot of performance work with Oracle RAC, SAP, and SQL Server this year, and there is a big difference between that and VSA testing.

When testing with big databases and the applications that go along with them, the storage requirements to achieve the needed performance levels are usually pretty high.  I've used big EMC, NetApp, HP Lefthand, and Dell Equallogic storage to support thousands of IOPs while maintaining low latency.  In these tests we are analyzing the storage usage in each test to ensure that we get the performance that we need. These big storage systems are necessary to meet the requirements of the applications being tested.

VSA is designed to be a simple to install, simple to use, and simple to manage storage solution for small environments.  It can be the first "SAN" for environments where it was not possible to have a SAN before.  It is not designed to support or be used with the types of workloads at the stress levels that I normally test with.  So approaching a performance study of VSA required something different.

Instead of trying to push as many IOPS as possible or getting as many users as possible, I focused on providing some insights into the key factors of VSA performance.  This includes a couple of test scenarios designed to show two different things.

The first used the VMmark2 workload to show that enterprise apps can run with good performance on VSA.  Specifically, it showed that Exchange, a webstore front and backend, and a Java based interactive website could all run very well, at the same time, while supporting the workload equivalent of over 1000 users.

The second test used IOBlazer (a cool and easy to use IO generator tool) to show how the VSA's Network RAID (or replication) traffic impacts the performance across the cluster as load is spread across the VSA cluster. This test illustrates how as you put load one datastore the network RAID that is ensuring the data is always available causes some load to also occur on a secondary node in the VSA cluster.  The graphs are cool in this section.

I think that most customers will probably not need the additional performance information that I have included with these scenarios because of how easy VSA is to use and manage, but it will help those that are interested in getting a more advanced understanding or want to get into a more detailed level of performance monitoring.  Most will not have need for this additional detail, but many geeks like me will be interested anyway.

So this approach is a bit different from the usual type of performance work that you see.  This isn't the million IOPS test or an Oracle RAC performance study.  It's meant for a different environment.  One that is getting it's first taste of shared storage and cool things like vMotion, DRS, and HA.


Tuesday, October 11, 2011

VMware Was Everywhere and Nowhere At Oracle Open World 2011

There was a running joke with everybody that came by the VMware booth at Oracle Open World this year.

"Wow, Oracle really doesn't like you guys!""What did you do to get back here?"  "Are they trying to hide you?" "You guys have been literally put in the corner!"

The VMware booth was literally in the back corner of the expo floor at OOW 2011.  Some of this was our fault for deciding to go with a smaller booth this year, but I think some of it may have to do with something else.

There were still lots of customers that came by and we had tons of discussion around running Oracle products on vSphere.  This year it seemed like there were more customers who were already running some or all of their Oracle databases on vSphere which was great.  I also spent some time explaining the concepts of virtualization and specifics about vSphere to customers who were new to the ideas which was also great.

From what I heard, talking to various speakers at OOW that I know, Oracle requested that all references to VMware be removed from their presentations and replaced with generic references.  But the speakers would go ahead and say "VMware" during the talk.

The final VMware highlight for me came during Larry Ellison's keynote on Wednesday afternoon.  He announced the new Oracle Cloud and gave a lengthy demo.  While announcing the Oracle Cloud he spent a fair amount of time describing why it was good.  You could take most of the statements that he made about the Oracle Cloud and put them directly into a keynote from VMware's Paul Maritz.  The Oracle vision for cloud and the VMware vision for cloud were similar in many ways.  Larry even used Paul's line about the Hotel California for proprietary clouds - VMs can check in, but they can never leave.  Larry, of course, never directly referenced VMware in his keynote, but the similar hybrid cloud strategy was definite.

So while Oracle preferred that VMware not be mentioned or seen at OOW, in reality VMware was everywhere.