NetApp Engineer

For obvious legal reasons, probably “The Valiant Young Toaster”

Image via Wikipedia

I’ve always quite enjoyed simple comic strips, Calvin & Hobbes, Dilbert, Farside and online ones like Penny Arcade. I have always toyed with the idea of creating one myself, but always lacked inspiration and artistic talent. I asked my good lady (who is very talented in the artistic department) to mock up a quick character for me, and I wanted to see what people think? I have a few ideas for plot lines and stories, but whether people are interested or not, it’s nice to have a creative moment aside from a technical day job!

But thought I’d post it here to get peoples feedback and maybe give me some encouragement to develop this idea a little more!

or Valiant Young Toaster

This is meant as a very quick guide to installing ONTAP onto disks that do not have an operating system already, or destroying an existing set of disks and re-installing ONTAP from scratch. Remember that this process is very destructive, any data on any disks attached to the system will be completely wiped and re-initialised. If you have disks that you want to attach to this system, but they also have data you want to keep on them, please make sure you leave them detached from the system until you have finished the disk initialisation process!

You will need a console connection to the sytem for most of the process, I’d recommend for all of it to be honest. You will have a filer head, and a shelf of disks. If this is going to be a cluster and you have software ownership enabled, then I’d first get the systems connected to their own disks and get ONTAP installed before you complete the full cluster cabling or any HA cabling.

If you just need to upgrade the installation of ONTAP, checkout ONTAP Upgrades.

If the system does not have a base installation on the Compact Flash card already, then you will need to first NetBoot the system.

When the system boots, you will be prompted to break the boot sequence (either CTRL+C or any key), shortly after this and the system POST checks, it’ll start loading the ONTAP version that is on the Compact Flash card. At this point you will be prompted to press CTRL+C to get special boot options made available. You’ll want to be watching as you want to catch this prompt, so hit CTRL+C. When the system has finished it’s POST checks, you’ll be warned about the partner if this is / was configured as a cluster, agree to this so long as you are sure you are ready!  Read more... (470 words, estimated 1:53 mins reading time)

This is one of those annoying situations that can cause things to come crashing down when you least expect it.

Locked snapshots can happen for several reasons, the obvious ones are that they are the basis of a SnapMirror or SnapVault update (despite both relying on the snapshots, they will only actually lock a snapshot during an active transfer, you can happily delete the snapshots otherwise and this will destroy the replication relationship, more or less). They can also be because of a vol copy, or for a very brief period a snap restore.

2 of the less obvious, but more common reasons are that of a LUN Clone and a FlexClone. Both in principle are fairly similar, but in practice act very different.

Simply a clone will base itself on a snapshot and then create a sparse clone based on this snapshot, and as such the original blocks of data, hence using no data. The clone can then be split, but 99/100 it will be used for some sort of verification or reporting and then removed.

A LUN Clone is the one that causes us most problems. As said, it creates a clone based on a snapshot, but the clone is created within the volume, and only of a particular LUN. This is infact a very similar concept to that of the new Single File FlexClone available in 7.3. Based on a given snapshot, you will have a new LUN created within the same volume as the parent LUN. This will use no storage, and is great for running verifications, or possibly testing or even reporting.  Read more... (635 words, estimated 2:32 mins reading time)

Following some feedback (thanks @CXI), I’ve rejigged the permalinks. Sorry if this causes any issues, but please give me a shout if anything appears broken now.

Now just need to get round to finishing up some of the draft posts I’ve had for a couple of weeks. Busy times at the moment!

I’m looking for some input and discussion around Cloud Computing and what people (real people) think it means and how they think it will affect them. I work in a heavy Sales environment and everyone is constantly talking about it as it has such a buzz at the moment. I’m looking for some feedback and honest opinions from people, whatever it may be.

Follow up with some input over at the NetApp Communities – http://communities.netapp.com/message/10087

Cheers!

This comes up quite a lot. There are a lot of stats available on the NetApp / N-Series systems. You can get them very easily through PerfStat, statit, stats, Operations Manager, and even the API. But what isn’t always clearly defined was what does each of these counters mean, and in the case of the histograms, what does each field represent?

You can get some information from “stats explain” (have a loot at Performance “stats” without PerfStat or Ops Mgr for more info), but this doesn’t include everything, and certainly doesn’t include much helpful information on some of the diagnostic stats.

I have spent a lot of time examining AutoSupports, and one little trump I found was that at the top of the “cm_stats” file was an XML listing of all the stats and their full description. Very useful! You don’t need to be a techie to turn XML into an Excel spreadsheet (in fact Excel does it for you), but as a good source for reference, please find attached a full listing of all the statistics and their descriptions for the NetApp systems.

cm_stats.xls

PerfStat is a great way to get some quite detailed performance information out of the filer when you have a performance or other issue that you can’t quite put your finger on. You need to have access to the PerfStat Viewer, or get someone to process this output for you, and then you need to trawl through it.

Operations Manager, and more specifically Performance Advisor is brilliant and 99% of the time gives you the counters you need to diagnose the problem. Once you’ve found your way round it, it is completely indispensible!

But what if you don’t have Operations Manager, or you just want to quickly pull out information on one area of the system?

First things you want to look at sysstat. Everyone’s best friend and great way of seeing “Is my system busy?”. Whenever you run sysstat, make sure to through it the “-s” modifier so that you get a summary at the end of the output. If you don’t define a number of iterations (-c <num>), then ctrl+c to break the output. “-x” is great for giving all areas of output, but it can be a little wide sometimes. “-u” is my favourite as it gives you utilisation readings and these the usually the most useful when troubleshooting.

Most of the columns are fairly self explanatory. CPU is % busy, NFS, CIFS, HTTP, FCP and iSCSI are all protocol operations counters. Net kB/s in and out are obvious (for reference a single gigabit interface will happily sustain around 80MB/s, but can stretch to 110/120MB/s). Disk and Tape in&out. Watch the cache age when it gets really low, but there’s better counters for that. Cache hit is a counter you want as close to 100% as possible. The more data is getting read from cache the better! CP Type is Consistency Points, I won’t go into detail as to what these are, there is a very good KB article on this already (https://now.netapp.com/Knowledgebase/solutionarea.asp?id=kb23471). And finally Disk Utilisation which seems to cause some confusion. This is the reading from the single busiest disk in the system, and not an average. This reading can interestingly go about 100% (much like CPU can too), and this simply means the disks are doing more than they should!  Read more... (1670 words, estimated 6:41 mins reading time)

I am a sucker, and I make a lot of choices without thinking, but just based on emotion. Which is why I own an Alfa Romeo! It was the car with the passion and soul (yes, I will continue to use this cliché) that I desired, and something that brought out the same in me. It was the car that fitted me personally, but is not to everyone else’s taste or choice.

However I’ve long been the believer that the ultimate modern car would be a hybrid. Not a gimmicky half electric thing, but a joint collaboration between several different manufacturers. To get the perfect car you need some of the following (sorry to any Americans, I love classic Detroit muscle, but I can’t place it in my perfect modern car!)

·         Italian design and passion

·         German mechanical engineering

·         Japanese electronics and computers

·         English flair and eccentricity

This car clearly doesn’t exist, and even if it did, it wouldn’t be a budget model! With cars you unfortunately can not use solutions architects to build the perfect automobile (as much as I am a total petrol head and would love the challenge!). But if this car did exist, it would be the perfect solution, and it would be built specifically for you. No two cars would be the same.

So how do we get this from a storage architecture? You’ve got the German mechanical excellence from people like HDS, the Japanese technology from people like NetApp, the English eccentricity from people like Pillar (to name but a few). I can’t think of any vendor that would fall into the Italian category, I don’t know of anyone who has ever bought a storage array for it’s passion and soul!  Read more... (613 words, estimated 2:27 mins reading time)

I created an Excel spreadsheet as I was tasked with creating a SnapMirror replication schedule for a customer that only had an 8meg line. The problem was that the replication would fail if more than 1 transferred happened at the same time. So I needed a way of calculating the rate of change, and designing the replication based on this.

The spreadsheet will calculate the snapmirror.conf schedule, but will also give you the commands to create, restrict and initialize the volumes.

 Read more... (491 words, estimated 1:58 mins reading time)

I have had a bit of a rock’n’roll past, I spent several years driving round with a motley bunch of pirates/musicians (The Klopeks) in my much loved LDV minibus playing in bars and basements up and down the UK. One thing that I’ve noticed with music is that people are easily led, if there is one person in the crowd that openly cheers and gets involved, everyone wants a part of it. Everyone knows that music has a scene, but I think that storage does too.

I find storage vendors and storage technology is very much like live gigs and like a music scene. If they already see someone else using something, they’ll be more likely to jump on that band wagon. If someone is already having a good time with it, surely I will too? Even if it doesn’t actually fit! There is definitely a ‘scene’ to the storage industry.

This can work absolutely fantastically, and this is one reason above most that I try to work above and beyond for my existing customers. If they have an issue, question or problem, doesn’t matter if it’s not my problem, I need to help them out. All too often I hear from other companies “that support expired 2 days ago I’m afraid”, or “technically that would be vendor x and not us I’m afraid”, and so the customer goes unloved. When we built our support infrastructure I said to our call centre “One rule above all others, never decline to take a support call”. Take the bull by the horns and get to the bottom of the issue and resolve them for the customer or they will not purchase again!  Read more... (1020 words, 2 images, estimated 4:05 mins reading time)