Queen: Return of the Champions DVD

(Originally posted 2005-11-14.)

As many people know I’ve been a Queen fan since 1974. And us Queen fans all know how we feel about Freddie Mercury’s death and the subsequent retirement of John Deacon. So it was with a mixture of anticipation and trepidation that I saw Queen + Paul Rodgers live in Hyde Park this summer. That was a great show. As these guys are all about 15 years older than me it’s nice to see that in a notoriously youth-oriented business they could still deliver. The parallel with the IT industry is obvious (not that I have to mention it to be able to blog here).:-)

So on my way through Heathrow I picked up the Queen: Return of the Champions DVD. It was all shot at a concert in Sheffield (with the exception of a very nicely done Imagine which was from Hyde Park).

I have to tell you it recreated the buzz I got when QPR strode onto the stage at Hyde Park. But this time I could see much more.

So, for Queen fans who can cope with the idea of Brian and Roger touring with someone other than Freddie, or for Paul Rodgers fans, this is one nice DVD.

A Movie You Might Like

(Originally posted 2005-11-14.)

At the weekend I went to see Flightplan, starring Jodie Foster and Sean Bean.

I thoroughly enjoyed it, despite the suspense of disbelief element. But it is a bit far-fetched.

To describe the plot – any further than the marketing material does – would be to totally spoil it for anyone who is thinking of seeing the movie. All I can say is that it is an airplane thriller, in the mould of Airforce One, which I also enjoyed.

But as someone who flies a lot I have to remind myself: This is a work of fiction.

Hardware Model Support in z/OS Release 7 RMF

(Originally posted 2005-11-11.)

This probably counts as my contribution to RMF for this decade. 🙂

RMF has long had the Software Model for a processor in SMF 70. Until z900 this was the same as the Hardware Model. With z900 you could have processors that were there but you hadn’t bought yet.

With z990 it got a lot worse as you could have between 1 and 4 books on the processor.

In z990 (and z9-109) studies we would know, for example, that the processor was a z990 Model 324 but wouldn’t be absolutely sure whether it was a 3-book or a 4-book machine. With a 324 there’s nowhere to go without installing a fourth book – if you needed to add processors. And we, frustratingly wouldn’t know that.

Now, with Release 7 RMF we get the hardware model in addition to the software model. So we expect in future engagements to be a little more sensitive to what it would take to upgrade.

Actually here’s what you could do today – on Release 6 or prior…

The Logical Processor Sections in the SMF 70 record do record under the PHYSICAL LPAR the processor numbers. Here’s what I saw for the above-mentioned z990 Model 324:

  • 00,02,05,07,08,0A,0C,0E
  • 20,22,25,27,28,2A,2C,2E
  • 30,32,35,37,38,3A,3C,3E

I wrote those in 2-digit hex format for a reason: The first digit is the book number.

So where’s Book 1, then?

It doesn’t exist. So I conclude this is a C24 (3-book) machine.

If this was your machine you’d probably be saying Well, I know I bought a 3-book machine but, in my consultancy, I think I’d like to know that, too.

One other thing: You can tell what the engine type is from these sections. In this case they’re all General-Purpose CPs (GCPs) and that corresponds to what we happen to know about the client: 2 12-way dedicated LPARs and no ICFs, IFLs or zAAPs.

Now none of that is an “intended interface” but it is fascinating. 🙂 But you are much better off with the 1.7 support for Hardware Model.

DDF and EWLM

(Originally posted 2005-11-11.)

I’ve not really gotten into EWLM and ARM – yet. But I think this APAR will be of interest to those who have. And I expect I will get interested in it when it’s more fully established…

PK11801 DDF FULLY-ENABLED EWLM ARM SUPPORT describes how the DDF support for EWLM / ARM is being made available to the general population of DB2 Version 8 sites. To quote:

DB2 for z/OS’ support for EWLM was initially shipped via APAR PQ91509. The support was installed disabled to control its initial use by customers while studies, etc., were performed to assess the support’s impact on a customer’s system and to evaluate if any further enhancements would be required. That investigation has concluded and additional enhancements have been provided on z/OS to minimize the impact of EWLM monitoring on a z/OS system. With the initial use period being concluded, the support will no longer need a special user modification to activate it.

I’m Back

(Originally posted 2005-11-11.)

One of the cardinal rules for a successful blog has been to write often. Clearly I’ve not done that for some time. Indeed I missed writing about zSeries Expo in San Francisco in September. And all I can say is that you really wouldn’t want to know about the internals of writing a Firefox extension, would you?

Well, maybe you would. 🙂

But it was (and is) a set of such small steps that reading about them here would be like watching paint dry.

So I subjected my IBM internal blog readership to that. 🙂

Seriously, the design work was incremental and required my internal users to be involved every step of the way. Hopefully, as a result, they got what they wanted – and I got the advice I needed.

I made the design decision to only support Firefox 1.5 and later. An informal poll 2 days ago (admittedly of a self-selecting group of IBMers who are committed to blogging and Firefox big-time) suggested that about 60% of Firefox users were already on 1.5 and so could use my extension. In the wild I expect the proportion would be smaller. But still those numbers vindicate my decision. And in 3 months time I expect almost nobody to still be on 1.0.x.

IRD and zAAPs

(Originally posted 2005-07-11.)

This is perhaps fairly basic for those of you who’ve read the fine print on zAAPs and IRD, but I needed to see it in someone’s data:

IRD Weight Management will feel free to vary the weight for the “Type 1” pool for a z/OS LPAR with zAAPs. But it will keep the weight the same for the “Type 2” pool – for the zAAP/IFA engines.

In other words an LPAR with z/OS and zAAPs could have two weights:

  • A varying weight for the GCPs
  • A static weight for the zAAPs

So in your code (and ours) you have to cope with the possibility of two weights.

I raise this now as I’ve just seen it in some data from one of the Washington Systems Center machines: The LPAR had an initial weight of 300 and the 10 GCPs’ weight dropped to 151. The 2 zAAPs’ weight stayed at precisely 300.

DB2 Instrumentation Changes – Documentation Updated

(Originally posted 2005-07-11.)

APAR PQ96908 accumulates updates to the DB2 for OS/390 and z/OS V7 and V8 IFCID flat files (DSNWMSGS) that occur in the last half of 2004 and the first half of 2005.

DSNWMSGS documents all the fields in each of the DB2 SMF records (and other DB2 instrumentation sources).

Personally I carry around a copy of this on my Thinkpad for reference so I think it’s time I downloaded a new copy.

Actually I also, amongst other things, refer to DSNx10.SDSNMACS and the SQL Reference for instrumentation information.

Paging Subsystem Design

(Originally posted 2005-07-05.)

Periodically on IBM-MAIN I’m caused to revisit something. With the advent of z990/z890 and “supposedly abundant” 🙂 real memory it seems to be time to revisit paging subsystem design.

You might perhaps think that in these days of zero paging you could skimp on paging subsystem design. And you’d be wrong. 😦

I’ve been following an IBM-MAIN discussion on this with interest. The discussion was about not exceeding 25% page data set busy. If you do, the received wisdom is that Auxiliary Storage Manager (ASM)’s Contiguous Slot Allocation algorithm will degrade. In this case utilisation means space rather than device utilisation (in RMF terms).

(There has been a change, which I don’t think materially affects this, round about the 1.2 timeframe, with a line item I’ll call more aggressive slot harvesting. But I don’t think that makes much difference to the argument about utilisation.)

Experiences in the not-too-distant past have caused me to think about page data set design from a different angle. I’ll call this the leave enough room to dump that large DB2/WAS address space argument. Actually, a fortiori, I’d say leave enough space to dump the whole of real storage. So that gives another Rule Of Thumb of leave free page space of about 1.5x the amount of real storage you have.

Note: Both the 25% and the 1.5x ROTs are trying to simplify probabilistic things (as always). So, you know in your shop what happens when you fail the ROT. In the former case paging performance tanks. In the latter it’s a real bad news day when that 6GB DB2 subsystem dumps. (I’ve seen the latter happen and it’s not pretty – when you don’t have the paging space to contain it.)

You don’t really have to choose which of these two considerations to follow. Go for both.

And finally… My friend Alvaro Salla (ex IBM Brazil) used to think the plural of Rule of Thumb was Rule of Thumbs. Makes sense as the plural of ROT must be ROTs. 🙂

GreaseMonkey

(Originally posted 2005-06-29.)

As a relative newcomer to the world of web programming I’ve been learning javascript. The reason I chose this language is (quite apart from already knowing java/swing) there is a very useful javascript tool called GreaseMonkey.

Greasemonkey allows you to modify web pages you’re browsing. Such modifications include

  • Inserting HTML into a page.
  • Deleting parts of a page.
  • Mergins stuff from another website.

At its most basic you can essentially get rid of annoyances in web pages that you consider to be poorly designed.

Greasemonkey scripts are written in javascript.

Note: This only works for Firefox. Personally I almost exclusively use Firefox. (I really like its tabbed browsing feature and the ability to write/obtain extensions that customise your browsing experience.)

GreaseMonkey is available from http://greasemonkey.mozdev.org

Things I could write about

(Originally posted 2005-06-15.)

Yesterday we IBM “pioneer” bloggers had a conference call where we thought about enhancements to this blogging site. One that seemed to get some measure of support was the notion of a place where readers could make unsolicited comments and ask questions.

I’m just writing about things I think are interesting. I’m not sure what my readership want to hear about. So I’m going to take a risk and invite you to suggest some topics. The risk is that I look foolish 🙂 or churlish 😦 by seeming to ignore your question.

You could either do it by sending me an e-mail (martin_packer@uk.ibm.com) or commenting on this entry.

There’s no guarantee that I know the answers 🙂 but it gives you a chance to steer what I blog on a little. If I can sensibly comment on something I will. And, just so my management don’t have a fit, this isn’t a substitute for “proper” Technical Support from IBM.

And, Mum, don’t ask me what I want for my dinner. 🙂