Fixing Two Small DELL Compellent Hardware Hiccups

Here’s two little tips to solve some small hardware issues you might run into with a Compellent SAN. But first, you’re never on your own with CoPilot support. They are just one phone call away so I suggest if you see these to minor issues you give them a call. I speak from experience that CoPilot rocks. They are really good and go the extra mile. Best storage support I have ever experienced.

Notes

  • Always notify CoPilot as they will see the alerts come in and will contact you for sure Smile. Afterwards they’ll almost certainly will do a quick health check for you. But even better during the entire process they keep an eye on things to make sure you SAN is doing just fine. And if you feel you’d like them to tackle this, they will send out an engineer I’m sure.
  • Note that we’re talking about the SC40 controllers & disk bays here. The newer genuine DELL hardware is better than the super micro ones.

The audible alert without any issues what so ever

We kept getting an audible alert after we had long solved any issues on one of the SANs. The system had been checked a couple of times and everything was in perfect working order. Except for that audible alarm that just didn’t want to quit. A low priority issue I know but every time we walk into the data center we were going “oh oh” for a false alert. That’s not the kind of conditioning you want. Alerts are only to be made when needed and than they do need to be acted upon!

Working on this with CoPilot support we got rid of it by reseating the upper I/O module. You can do this on the fly – without pulling SAS-cables out or so, they are redundant, as long as you do it one by one and the cabling is done right (they can verify that remotely for you if needed).

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But we got lucky after the first one. After the “Swap Clear” was requested  every warning condition was cleared and we got rid of the audible alert beep!  Copilot was on the line with us and made sure all paths are up and running so no bad things could happen. That’s what you have a copilot for.

Front panel display dimming out on a Compellent Disk Bay

We have multiple Compellent SANs and on one of those we had a disk bay with a info panel that didn’t light up anymore. A silly issue but an annoying one as this one also show you the disk bay ID.

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Do we really replace the disk bay to solve this one? As that light had come on and of a couple of time it could just be a bad contact so my colleague decided to take a look. First  he removed the protective cover and then, using some short & curved screw drivers, he took of the body part. The red arrow indicates the little latch that holds the small ribbon cable in place.

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That was standing right open. After locking that down the info appeared again on the panel. The covers was screwed on again and voila. Solved.

TechNet Top Support Solutions From Microsoft Support Blog

As this year comes to an end I’d like to draw your attention to Microsoft’s new Top Support Solutions blog on TechNet. It was created this as part of their continuous efforts to keep the various  technical communities informed about the most relevant answers to the top questions or issues experienced with their products. They identify these top issues by analyzing the question in their forums and their other support channels.

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So if you need to find answers for your self or your customers go take a look at the "Top Solutions Content" blog. Changes are you’ll find valuable information about the Microsoft top support solutions for several of their popular products in Server and Tools. It might save you and your clients or manager a lot of time, effort and money. It’s also a great resource to make your colleagues, community, user group or clients aware of.

DELL Server DRAC Card Soft Reset With Racadmin

Sometimes a DRAC goes BOINK

Sometimes a DRAC (Dell Remote Access Card) can give you issues. Sometimes it’s some lingering process or another hiccup that causes this. You can try a reboot but that doesn’t always fix the issue. You can go into the BIOS and cancel any running System Services. A “confused” DRAC card can also be fixed by shutting down the server and cutting power for 5 to 10 minutes. That’s good to know as a last resort but not very feasible a lot of times, bar a maintenance window when you’re on premise.

You can also try to do a local or a remote reset of the DRAC card via OpenManage  (OMSA), racadmin. See RACADM Command Line Interface for DRAC for more information on how and when to use this tool. The racadmin can be used for a lot of remote configuration and administration and one of those is a “soft reset” or basically a powercycle, aka reboot, of the drac card itself. Don’t worry your server stays up Smile.

Local: racadmin racreset soft

Remote: racadm -r <ip address> -u <username> -p <password> racreset soft

Real life example

I was doing routine maintenance on 4 Hyper-V clusters and as part of that DUPs (Dell update packages) were being deployed to upgrade some firmware. This can be automated nicely via Cluster Aware Updating and the logging option will help you pin point the issue. See https://blog.workinghardinit.work/2013/01/09/logging-cluster-aware-updating-hotfix-plug-in-installations-to-a-file-share/ for more information on this.

Just like we found that the DRAC upgrade was not succeeding on two nodes.

One it was due to the DUP not being able to access the Virtual USB Device

Software application name: iDRAC6
   Package version: 1.95
   Installed version: 1.92

Executing update…

Device does not impact TPM measurements.

Device: iDRAC6, Application: iDRAC6
  Failed to access Virtual USB Device

==================> Update Result <==================

Update was not applied

================================================

Exit code = 1 (Failure)

and the other was because there was some other lingering DRAC process.

 iDRAC is currently unable to process this request because of another task.
  Please attempt one or more of the following steps to cancel the pending iDRAC task:
  1) Wait 30 minutes and retry your request.
  2) Reboot the system; Press F10; select ‘Exit and Reboot’ from Unified Server Configurator, and retry your request.
  3) Reboot the system; Press Ctrl-E; select ‘System Services’. Then change ‘Cancel System Services’ to YES, which will close the pending task;
      Then press Enter at the warning message. Press ESC twice and select ‘Save Changes and Exit’ and retry your request.

==================> Update Result<==================

Update was not applied

================================================
Exit code = 1 (Failure)

They give some nice suggestions but the racreset is another nice one to have I your toolkit. It’s fast and effective.

Run racadmin racreset soft

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Wait for a couple of minutes and then run the DUP or the items in SUU that failed. With some luck this will succeed now.

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A reality Check On Disaster Recovery & Business Continuity

Introduction

Another blog post in “The Dilbert Life Series®” for those who are not taking everything personal. Every time business types start talking about business continuity, for some reason, call it experience or cynicism, my bull shit & assumption sensors go into high alert mode. They tend to spend a certain (sometimes considerable) amount of money on connectivity, storage, CPUs at a remote site, 2000 pages of documentation and think that covers just about anything they’ll need. They’ll then ask you when the automatic or 5 minute failover to the secondary site will be up and running. That’s when the time has come to subdue all those inflated expectations and reduce the expectation gap between business and IT as much as possible. It should never have come to that in the first place. But in this matter business people & analysts alike, often read (or are fed) some marchitecture docs with a bunch of sales brochures which make it al sound very easy and quickly accomplished. They sometimes think that the good old IT department is saying “no” again just because they are negative people who aren’t team players and lack the necessary “can do attitude” in world where their technology castle is falling down. Well, sorry to bust the bubble, but that’s not it. The world isn’t quite that black and white. You see the techies have to make it work and they’re the ones who have to deal with the real. Combine the above with a weak and rather incompetent IT manager bending over to the business (i.e. promising them heaven on earth) to stay in there good grace and it becomes a certainty they’re going to get a rude awakening. Not that the realities are all that bad. Far from it, but the expectations can be so high and unrealistic that disappointment is unavoidable.

The typical flow of things

The business is under pressure from peers, top management, government & regulators to pay attention to disaster recovery. This, inevitably leads to an interest in business continuity. Why, well we’re in a 24/7 economy and your consumer right to buy a new coffee table on line at 03:00 AM on a Sunday night is worth some effort.  So if we can do it for furniture we should certainly have it for more critical services. The business will hear about possible (technology) solutions and would like to see them implemented. Why wouldn’t they? It all sounds effective and logical. So why aren’t we all running of and doing it? Is it because IT is a bunch of lazy geeks playing FPS games online rather than working for their mythically high salaries? How hard can it be? It’s all over the press that IT is a commodity, easy, fast, dynamic and consumer driven so “we” the consumers want our business continuity now! But hey it costs money, time, a considerable and sustained effort and we have to deal with the less than optimal legacy applications (90% of what you’re running right now).

Realities & 24/7 standby personnel

The acronyms & buzz words the business comes up with after attending some tech briefing by Vendors Y & Z (those are a bit like infomercials but without the limited value those might have Sarcastic smile) can be quite entertaining. You could say these people at least pay attention to the consumerized business types. Well actually they don’t, but they do smell money and lots of it. Technically they are not lying. In a perfect world things might work like that … sort of, some times and maybe even when you need it. But it will really work well and reliable. Sure that’s not the vendors fault. He can’t help  that the cool “jump of a cliff” boots he sold you got you killed. Yes they are designed to jump of a cliff but anything above 1 meter without other precautions and technologies might cause bodily harm or even death. But gravity and its effects in combination with the complexity of your businesses are beyond the scope of their product solutions and are entirely your responsibility. Will you be able to cover all those aspects?

Also don’t forget the people factor. Do you have the right people & skill sets at your disposal 24/7 for that time when disaster strikes? Remember that could be on a hot summer night in a weekend when they are enjoying a few glasses of wine at a BBQ party and not at 10:15 AM on a Tuesday morning.

So what terminology flies around?

They hear about asynchronous or even synchronous replication of storage of applications. Sure it can work within a data center, depending on how well it is designed and setup. It can even work between data centers, especially for applications like Exchange 2010. But let’s face it, the technical limitations and the lack of support for this in many of the legacy applications will hinder this considerably.

They hear of things like stretched clusters and synchronous storage replication. Sure they’ll sell you all kinds of licensed features to make this works at the storage level with a lot of small print. Sometimes even at the cost of losing functionality that makes the storage interesting in the first place. At the network level anything below layer 3 probably suffers from too much optimism. Sure stretched subnets seem nice but … how reliable are these solutions in real live?

Consider the latency and less reliable connectivity.You can and will lose the link once in a while. With active-active or active-passive data centers that depend on each other both become single points of failure. And then there are all the scenarios where only one part of the entire technology stack that makes everything work fails. What if the application clustering survives but not the network, the storage or the database? You’re toast any way. Even worse, what if you get into a split brain scenario and have two sides writing data. Recover from that one my friend, there’s no merge process for that, only data recovery. What about live migration or live motion (state, storage, shared nothing) across data centers to avoid an impending disaster? That’s a pipe dream at the moment people. How long can you afford for this to take even if your link is 99.999% reliable? Chances are that in a crisis things need to happen vast to avoid disaster and guess what even in the same data center, during normal routine operations, we’re leveraging <1ms latency 10Gbps pipes for this. Are we going to get solutions that are affordable and robust? Yes, and I think the hypervisor vendors will help push the entire industry forward when I see what is happening in that space but we’re not in Walhalla yet.

Our client server application has high availability capabilities

There are those “robust and highly available application architectures” (ahum) that only hold true if nothing ever goes wrong or happens to the rest of the universe. “Disasters” such as the server hosting the license dongle that is rebooted for patching. Or, heaven forbid, your TCP/IP connection dropped some packages due to high volume traffic. No we can’t do QoS on the individual application level and even if we could it wouldn’t help. If your line of business software can’t handle a WAN link without serious performance impact or errors due to a dropped packet, it was probably written and tested on  <1ms latency networks against a database with only one active connection. It wasn’t designed, it was merely written. It’s not because software runs on an OS that can be made highly available and uses a database that can be clustered that this application has any high availability, let alone business continuity capabilities. Why would that application be happy switching over to another link. A link that is possibly further away and running on less resources and quite possibly against less capable storage? For your apps to works acceptably in such scenarios you would already have to redesign them.

You must also realize that a lot of acquired and home written software has IP addresses in configuration files instead of DNS names. Some even have IP addresses in code.  Some abuse local host files to deal with hard coded DNS names … There are tons of very bad practices out there running in production. And you want business continuity for that? Not just disaster recovery  to be clear but business continuity, preferably without dropping one beat. Done any real software and infrastructure engineering in your life time have you? Keeping a business running often looks like a a MacGyver series. Lots creativity, ingenuity, super glue, wire, duct tape and Swiss army knife or multi tool. This is still true today, it doesn’t sound cool to admit to it, but it needs to be said.

We can make this work with the right methodologies and strict processes

Next time you think that, go to the top floor and jump of, adhering to the flight methodologies and strict processes that rule aerodynamics. After the loud thud due to you hitting the deck, you’ll be nothing more than a pool of human waste. You cannot fly. On top of unrealistic scenarios things change so fast that documentation and procedures are very often out of date as soon as they are written.

Next time some “consultants” drop in selling you products & processes with fancy acronyms proclaiming rigorous adherence to these will safe the day consider the following. They make a bold assumption given the fact they don’t know even 10% of the apps and processes in your company. Even bolder because they ignore the fact that what they discover in interviews often barely scratches the surface. People can only tell you what they actually know or dare tell you. On top of that any discovery they do with tools is rather incomplete. If the job consist of merely pushing processes and methodologies around without reality checks you could be in for a big surprise. You need the holistic approach here, otherwise it’s make believe. It’s a bit like paratrooper training for night drops over enemy strong holds, to attack those and bring ‘m down. Only the training is done in a heated class room during meetings and on a computer. They do not ever put on all their gear, let alone jump out of an aircraft in the dead of night, regroup, hump all that gear to the rally points and engage the enemy in a training exercise. Well people, you’ll never be able to pull of business continuity in real life either if you don’t design and test properly and keep doing that. It’s fantasy land. Even in the best of circumstances no plan survives it first contact with the enemy and basically you would be doing the equivalent of a trooper firing his rifle for the very first time at night during a real engagement. That’s assuming you didn’t break your neck during the drop, got lost and managed to load the darn thing in the first place.

You’re a pain in the proverbial ass to work with

Am I being to negative? No, I’m being realistic. I know reality is a very unwelcome guest in fantasy land as it tends to disturb the feel good factor. Those pesky details are not just silly technological “manual labor” issues people. They’ll kill your shiny plans, waste tremendous amounts of money and time.

We can have mission critical applications protected and provide both disaster recovery and business continuity. For that the entire solution stack need to be designed for this. While possible, this makes things expensive and often only a dream for custom written and a lot of the shelf software. If you need business continuity, the applications need to be designed and written for it. If not, all the money and creativity in the world cannot guarantee you anything. In fact they are even at best ugly and very expensive hacks to cheap and not highly available software that poses as “mission critical”.

Conclusion

Seriously people, business continuity can be a very costly and complex subject. You’ll need to think this through. When making assumptions realize that you cannot go forward without confirming them. We operate by the mantra “assumptions are the mother of al fuckups” which is nothing more than the age old “Trust but verify” in action. There are many things you can do for disaster recovery and business continuity. Do them with insight, know what you are getting into and maybe forget about doing it without one second of interruption for your entire business.

Let’s say disaster strikes and the primary data center is destroyed. If you can restart and get running again with only a limited amount of work and productivity lost, you’re doing very well. Being down for only a couple of hours or days or even a week, will make you one of the top performers. Really! Try to get there first before thinking about continuous availability via disaster avoidance and automatic autonomous failovers.

One approach to achieve this is what I call “Pandora’s Box”. If a company wants to have business continuity for its entire stack of operations you’ll have to leave that box closed and replicate it entirely to another site. When you’re hit with a major long lasting disaster you eat the down time and loss of a certain delta, fire up the entire box in another location. That way you can avoid trying to micro manage it’s content. You’ll fail at that anyway. For short term disasters you have to eat the downtime. Deciding when to fail over is a hard decision. Also don’t forget about the process in reverse order. That’s another part of the ball game.

It’s sad to see that more money is spend consulting & advisers daydreaming than on realistic planning and mitigation. If you want to know why this is allowed to happen there’s always my series on The do’s and don’ts when engaging consultants Part I and Part II. FYI, the last guru I saw brought into a shop was “convinced” he could open Pandora’s Box and remain in control. He has left the building by now and it wasn’t a pretty sight, but that’s another story.