I’ve been invited and I’m attending the CIO Executive Summit with DELL’s Executive Leadership Team on Wednesday September 17, 2014 in Brussels. It’s an opportunity to meet and network with my peers and IT leaders. It also provide the opportunities to discuss challenges with Dell executives and where they see DELL help us with those.
I’ll be attending 2 “Strategic Deep Dive Sessions” that address some of critical challenges facing IT C-Level professionals. I’m doing the one on security. This is important as alone eternal vigilance, preparedness & situational awareness can help mitigate disaster. The technology is just a force multiplier.
The other track is on future ready IT solutions. That means a lot different thins to many of us. The new capabilities and ever faster evolving IT places a financial and operational burden on everyone. I’m very interested to discuss how DELL will deal with this beyond the traditional answers. The need for fast, effective & cost effective solutions that deliver great ROI & TCO is definitely there but the move to OPEX versus CAPEX and the potential loss of ownership also introduces risk that can cost us dearly if not managed right. IT, is still more than a financial model of service billing, even if sometimes it looks like that. It’s important to keep the mix in balance & do it smart.
So on Wednesday I’ll be focusing on strategy and not action or tools. Something that get’s missed way too much by way too many way too often. Michael Dell will be there and if I get the opportunity I’ll be happy to give some feedback.
and the great DELL generation 13 PowerEdge Servers mean for the Hyper-V and SQL server environments under my care.
For the Hyper-V clusters I’m in heaven. At least for now as Windows is still licensed per socket at the time of writing. vNext has me worried a bit, thinking about what would happen if that changes to core based licensing to. Especially with SQL Server virtualization. I do hope that if MSFT ever goes for per core licensing for the OS they might consider giving us a break for dedicated SQL Server Hyper-V clusters.
For per core licensing with SQL Server Enterprise we need to run the numbers and be smart in how we approach this. Especially since you need Software Assurance to be able to have mobility & failover / high availability. All this at a time you’re told significant cost cutting has to happen all over the board.
So what does this mean? The demise of SQL Server in the Enterprise like some suggest. Nope. The direct competitors of SQL Server in that arena are even more expensive. The alternatives to SQL are just that, in certain scenarios you don’t need SQL (Server) or you can make due with SQL Server Express. But what about all the cases where you do really need it? You’ll just have to finance the cost of SQL Server. If that’s not possible the business case justifying the tool is no longer there, which is valid. As the saying goes, if you can’t afford it, you don’t need it. A bit harsh yes, I realize, but this is not a life saving medicine we’re talking about but a business tool. There might be another reason your SQL Server licensing has become unaffordable. You might be wasting money due to how SQL Server is deployed and used in your environment. To make sure you don’t overpay you need to evaluate if SQL Server consolidation is what is really needed to save the budget.
Now please realize that consolidation doesn’t mean stupidly under provisioning hardware & servers to make budget work out. That’s just plain silly. For some more information on this, please read Virtualizing Intensive Workloads on Hyper-V, Can It Be Done
So what is smart consolidation (not all specific to SQL Server by the way):
You have to avoid physical SQL Server sprawl with a vengeance.
You need to consolidate SQL Servers aggressively.
Virtualize on a dedicated SQL Server Hyper-V cluster if possible
Favor scale out over scale up in the Hyper-V scenario to keep node costs reasonable and allow for affordable expansion.
Use 2 socket servers and replace the hardware faster to keep the number of needed cores down.
This allows to leverage modern commodity, high performance storage, networking and compute where you can in order to optimize workloads & minimize costs.
It helps save on power consumption & cooling
More nodes with lesser cores (scale out approach) reduces VM density per node but also keep the cost of adding a node (with SQL Server per core licensing, or when it comes to that for the OS as well), which is your scaling block with a fixed cost under control. It’s all about balance and it isn’t as easy as it seems.
Play the same game with storage. This can be a harder sale to make internally. Traditionally people hang on to storage longer due to the high CAPEX. I have said it before, storage vendors have to deliver more & better. Even the challengers & hyper converged systems are still too expensive to really get into a short renewal cycle for most organizations.
Be smart about it. A great DBA can make a difference here and some hard core performance tuning is what can save a serious amount of money. If on top of that you have some good storage & network skills around you can achieve a lot. Next to the fact that you’ll have to spend serious money for serious workloads the ugly truth is that consolidation requires you find your peak loads and scale for those with a vengeance. Look, maxing out one server on which one SQL Server is running isn’t that bad. But what if 3 SQL Servers running a peak performance spread over a 3 node Hyper-V cluster dedicated to SQL Server VMs might kill performance all over!
The good news is I have solid ideas,visions, plans and options to optimize both the on premise & cloud of part of networking, storage & compute. Remember that there is no one size fits all. Execution follows strategy. The potential for very performant, cost effective & capable solutions are right there. I cannot give you a custom solution for your needs in a blog post. One danger with fast release cycles is that it requires yearly OPEX end if they cannot guarantee it the shift in design to solutions with less longevity could become problematic if they can’t come up with the money. Cutting some of the “fat” means you will not be able to handle longer periods of budget drought very well. There is no free lunch.
So measure twice & cut once or things can go wrong very fast and become even more expensive.
You might think this sounds a bit pessimistic. No this is an opportunity, especially for a Hyper-V MVP who happens to be a MCDBA . The IT skills shortage is only growing bigger all over the planet, so not too much worries there, I won’t have to collect empty bottles for a living yet. The only so called “draw back” here could be that the environments I take care of have been virtualized and optimized to a high extend already. The reward for being good is sometimes not being able to improve things in orders of magnitude. Bad organizations living in a dream world, the ones without a solid grasp of the realities of functional IT in practice, might find that disappointing. Yes the “perception is reality” crowd. Fortunately the good ones will be happy to be in the best possible shape and they’ll invest money to keep it that way. Interesting times ahead.
When you get your Force10 switches up and running and are about to configure them you might notice that, when looking at the logs, the default timestamp is the time passed since the switch booted. During configuration looking at the logs can very handy in seeing what’s going on as a result of your changes. When you’re purposely testing it’s not too hard to see what events you need to look at. When you’re working on stuff or trouble shooting after the fact things get tedious to match up. So one thing I like to do is set the time stamp to reflect the date and time.
This is done by setting timestamps for the logs to datetime in configuration mode. By default it uses uptime. This logs the events in time passed since the switch started in weeks, days and hours.
it’s just that the line is to long and your prompt is scrolling .
This gives me the detailed information I want to see. Opting to display the time zone and helps me correlate the events to other events and times on different equipment that might not have the time zone set (you don’t always control this and perhaps it can’t be configured on some devices).
As you can see the logging is now very detailed (purple). The logs on this switch were last cleared before I added these timestamps instead op the uptime to the logs. This is evident form the entry for last logging buffer cleared: 3w6d12h (green).
Voila, that’s how we get to see the times in your logs which is a bit handier if you need to correlate them to other events.
I was deploying a bunch of PowerConnect 2808 switches that needed to provide connectivity to multiple VLANs (Training, Guest, …) in classrooms. I should have figured it out before I got there with my “assumption” based quick configuration loaded on the switches if I had just refreshed my insights in how the PowerConnect family of switches work. Setting Up A Uplink (Trunk/General) With A Dell PowerConnect 2808 or 28XX series switch differs a bit from the higher-end PowerConnect.
Setting Up A Uplink (Trunk/General) With A Dell PowerConnect 2808 or 28XX
PowerConnect port mode refresher
So before we go on, here are the basics on switch port (or LAG) modes in the PowerConnect family. Please realize that switch behavior (especially for trunk mode in this context) has changed over time with more recent switches/firmware. But the current state of affairs is as follows (depending on what model & firmware you have behavior differs a bit).You can put your port or LAG in the following 3 (main) modes:
Access
The port belongs to a single untagged VLAN. When a port is in Access mode, the packet types which are accepted on the port cannot be designated. Ingress filtering cannot be enabled/disabled on an access port. So only untagged received traffic is allowed and all transmitted traffic is untagged. The setting of the port determines the VLAN of traffic. Tagged received traffic is dropped. Basically, this is what you set your ports for client devices to (printer, PC, laptop, NAS).
Trunk
In older versions this means that ALL transmitted traffic is tagged. That’s easy. Tagged received traffic is dropped if doesn’t belong to one of the defined VLAN on the trunk. In more recent switches/firmware untagged received traffic is dropped but for one VLAN, that can be untagged and still be received. Which is nice for the default VLAN and makes for a better compatibility with other switches.
General
You determine what the rules are. You can configure it to transmit tagged or untagged traffic per VLAN. Untagged received traffic is accepted and the PVID determines the VLAN it is tagged with. Tagged received traffic is dropped if doesn’t belong to one of the defined VLANs.
Setting Up A Uplink (Trunk/General) With A Dell PowerConnect 2808 or 28XX
These are good switches for their price point & use cases. Just make sure you buy them for the right use case. There is only one thing I find unforgiving in this day and age: the lack of SSH/HTTPS support for management.
Go ahead fire up a 2808 and take a look at the web interface and see what you can configure. In contrast with the PC54XX/55XX etc. Series you cannot set the port mode it seems. So how can this switch accommodate trunks/general/access modes at all. Well it’s implied in the configuration of ports that seem to be set in general mode by default and you cannot change that. The good news is that with the right setting a port in general mode behaves like a port in access or trunk mode. How? Well we follow the rules above.
So we assume here that a port is in general mode (can’t be changed). But we want trunk mode, so how do we get the same behavior? Let’s look at some examples in speudo CLI. (It’s web GUI only device).
Example 1: Classic Trunk = only defined tagged traffic is accepted. All untagged traffic is dropped
So we can have the same behavior is general mode using
switchport mode general switchport general allowed vlan add 9, 20 tagged switchport general pvid 4095
The PVID of 4095 is the industry standard discard VLAN, it assign this VLAN to all untagged traffic which is dropped. Ergo this is the same as the trunk config above!
Example 2: Modern Trunk = only defined tagged traffic and one untagged VLAN is accepted
So we can have the same behavior is general mode using
switchport mode general switchport general allowed vlan add 9, 20 tagged switchport general pvid 1
This example is what we needed in the classroom. And is basically what you set with the GUI. So far so good. But we ran into an issue with connectivity to the access ports in VLAN 9 and VLAN 20. Let’s look at that in the next Example
Example 3: Access port mode = only one untagged VLAN is accepted
switchport mode access switchport access vlan 9
Switchport mode general switchport general allowed vlan add 9 untagged switchport general pvid 9
If you’re accustomed to the higher end PC switches you define the port in access mode and add the VLAN of you choice untagged. That’s it. Here the mode is general and can’t be changed meaning we need to set the PVID to 9 so all untagged traffic is indeed tagged with VLAN 9 on the port.
Setting Up an uplink between a PowerConnect 5548 and a 2808
Here’s the normal deal with higher range series of PowerConnect switches: you normally use the port mode to define the behavior and in our case we could go with a trunk or general mode. We use trunk, leave the native VLAN for the one untagged VLAN and add 9 and 20 as tagged VLANs.
The “trunk” port of LAG is left on the default PVID
So an “access” port for VLAN 9 is is achieved by setting the PVID to 9
And an “access” port for VLAN 20 is achieved by setting the PVID to 20
While the VLAN membership settings are what you’d expect them to be like on the higher end PowerConnect models:
First, VLAN 1 (native),
then LAN 9 (Corp),
and finally, VLAN 20 (Guest)
Conclusion
If it’s the first time configuring a PC2808 you might totally ignore the fact that needed to do some extra work to make traffic flow. There is no selection of access/general/trunk on a PowerConnect 2808. The port or LAG is “implicitly” set to general. The extra settings of the PVID and adding tagged/untagged VLANs will make it behave as general, trunk or access.
Set any other VLAN than the default 1 to tagged on the port or LAG you’ll use as uplink. So far things are quite “standard PowerConnect”.
You set the VLAN membership of your “access” ports to untagged to the VLAN you want them to belong to.
After that in on the “access” ports you set the PVID to the VLAN you want the port to belong to. If you do not do this the port still behaves as if it’s a VLAN 1 port. It will not get a DHCP address for that VLAN but for for the the one on VLAN 1 if there is one, or, if you use a static IP address for the subnet of a VLAN on that port you won’t have connectivity as it’s not set to the right VLAN.
The reason we used the PowerConnect 2808 series here is that they needed silent ones (passive cooling) in the training rooms. Multiple ones to avoid too many cables running around the place. That was the outcome of 2 minutes at the desk of the project manager’s quick fix to a changed requirement. The real solution of cause would have been to get 24+ outlets to the room in the correct places and add 24+ ports to the normal switch count in the hardware analysis for the building solution. But after the facts, you have to roll with the flow.
. The IT skills shortage is only growing bigger all over the planet, so not too much worries there, I won’t have to collect empty bottles for a living yet. The only so called “draw back” here could be that the environments I take care of have been virtualized and optimized to a high extend already. The reward for being good is sometimes not being able to improve things in orders of magnitude. Bad organizations living in a dream world, the ones without a solid grasp of the realities of functional IT in practice, might find that disappointing. Yes the “perception is reality” crowd. Fortunately the good ones will be happy to be in the best possible shape and they’ll invest money to keep it that way. Interesting times ahead.
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