A colleague has been working to set up a MS NLB cluster for a set of .NET machines. As is our standard practice, these are created as ESX VMs, and for convenience, we create them based on our standard template. Then the VMware guest customization process runs, and we have a VM we can turn over to the application team.
The problem in this case (the reason I'm involved in a Windows issue) is that NLB wasn't starting. There were various false-starts with configuration items randomly disappearing (why is only one of the NICs in the selection box on this system?).
Somehow, it was suggested that maybe the reason NLB wouldn't start was because the SID of the two VMs was the same. Of course, no, since we run the guest customization which does a NewSID(1m). That'd be impossible.
But it turns out that the SIDs were the same, popping the machines out of the domain and newsid'ing them resolved the issue. Whod'a thunk?
On further reflection, the system's SID is probably the best option for a locally-unique identifier to use to map the loadbalancing traffic via NLB. There has to be some way for all the cluster members to agree on who cares about which packets, so why not use the SID as part of the hash function? Makes perfect sense, since SIDs are, of course, unique.
--Joe
2010/07/09
2010/03/29
Is today the last $weekday of the month?
Classic problem in sysadmin: How to run a script on the last Sunday (or whatever day) of the month. This snippet is correct for all days, even in leap years between 1904 and 2096, inclusive. It messes up on February 22 each century, except when the year is divisible by 400 (works in 1600, 2000, 2400, etc. but breaks in 2100, 2200, 2300) But I'll be retired by then...
My answer, in Korn Shell:
My answer, in Korn Shell:
# Day of the week to run on:
DOW=Sunday
OLDLC_TIME=$LC_TIME
export LC_TIME=C
# Requires /usr/bin/ksh to run correctly.
# I couldn't be bothered to get the expr quoting and backquoting working in /bin/sh
case `date +%b` in
Jan|Mar|May|Jul|Aug|Oct|Dec) D=31;;
Apr|Jun|Sep|Nov) D=30;;
Feb) D=$(( 28 + ( $(date +%Y) %4 == 0 ));;
# FIXME: Y2.1K bug here.
esac
if [[ `date +%A` == "$DOW" ]] && [[ $(( $(date +%e) + 7 -gt $D ]]
# then next Sunday is after the end of this month, so today's the last Sunday of this month
then
....
fi
LC_TIME=$OLDLC_TIME
2009/11/09
IT Reporting
A recent "Ask Slashdot" asked what information a sysadmin should take to an executive. Here's what I think. I've picked this up from a variety of sources, including a very-skilled manager.
--------------------------
There are three key things that executives want to hear:
1) What has the department done in the past? The core of this point is to get to the question "Does the past justify continued investment?" and its correlary "We've sunk so much money into IT, what have we gotten from it?" This is where usage statistics (website hits, business transaction data, dollars-per-downtime and Nines, return on cost-saving measures, etc) are presented. This should be in high-level terms with drill-down slides available, but only presented on request. Focus on the trends of service delivery vs. IT budget and/or headcount.
2) What is the department doing now? Here we focus on what is happening with their current business. This is where a primary element of capacity planning comes in: The Headroom Metric. How much additional user load can we support on our current systems and network, before the service is degraded? In concrete terms, ignoring everything except CPU, if you're delivering 100 pages per second, and using 40% of the server's CPU, you have a headroom of 150 additional pp/s. By extrapolating this to the business need - say the marketing department has launched 5 campaigns this year, the current systems may be able to support 10, but should not be expected to support 20 without additional investment. Note that this headroom metric must look at the end-to-end utilization, like disk, memory, network, and most importantly administration effort in order to be accurate.
3) What will the department do in the future? What are the business-focused projects that the department is working on? How will the investment in these projects result in money coming into or staying in the business? What is the Return on Capital, Return on Investment?
As far as timing, there should be at least an annual "full report" on the state of IT. Depending on the dynamics of the business, quarterly updates should be sufficient, unless something changes significantly. And depending on the team and scope of the projects. You don't want to face this with a "we haven't done anything since the last report" status. But it's also important to reconnect with the executives regularly so that they don't forget about what you're doing, and also so that you can react and change to meet their changing business plans.
The most important thing we in IT can do is to be aligned to the business. This means focusing on the things that matter: delivering the product or service in exchange for money. Everything else is overhead. And the better your IT department is at aligning itself, the better you look when an outsourcer tries to talk your executives into cutting everything except the "core competancies".
--Joe
--------------------------
There are three key things that executives want to hear:
1) What has the department done in the past? The core of this point is to get to the question "Does the past justify continued investment?" and its correlary "We've sunk so much money into IT, what have we gotten from it?" This is where usage statistics (website hits, business transaction data, dollars-per-downtime and Nines, return on cost-saving measures, etc) are presented. This should be in high-level terms with drill-down slides available, but only presented on request. Focus on the trends of service delivery vs. IT budget and/or headcount.
2) What is the department doing now? Here we focus on what is happening with their current business. This is where a primary element of capacity planning comes in: The Headroom Metric. How much additional user load can we support on our current systems and network, before the service is degraded? In concrete terms, ignoring everything except CPU, if you're delivering 100 pages per second, and using 40% of the server's CPU, you have a headroom of 150 additional pp/s. By extrapolating this to the business need - say the marketing department has launched 5 campaigns this year, the current systems may be able to support 10, but should not be expected to support 20 without additional investment. Note that this headroom metric must look at the end-to-end utilization, like disk, memory, network, and most importantly administration effort in order to be accurate.
3) What will the department do in the future? What are the business-focused projects that the department is working on? How will the investment in these projects result in money coming into or staying in the business? What is the Return on Capital, Return on Investment?
As far as timing, there should be at least an annual "full report" on the state of IT. Depending on the dynamics of the business, quarterly updates should be sufficient, unless something changes significantly. And depending on the team and scope of the projects. You don't want to face this with a "we haven't done anything since the last report" status. But it's also important to reconnect with the executives regularly so that they don't forget about what you're doing, and also so that you can react and change to meet their changing business plans.
The most important thing we in IT can do is to be aligned to the business. This means focusing on the things that matter: delivering the product or service in exchange for money. Everything else is overhead. And the better your IT department is at aligning itself, the better you look when an outsourcer tries to talk your executives into cutting everything except the "core competancies".
--Joe
2009/09/29
Idle curiosity about iLOM
Why does the service processor on our brand new Sun T5240 server have a SPARC 885 processor, and run Linux? Why not (Open)Solaris?
Kinda ironic that Sun boots its latest servers with Linux.
Maybe it's the fact that it has 32MB of flash to work with, and only 128MB of ram. But that should be enough to run Solaris.
--Joe
Kinda ironic that Sun boots its latest servers with Linux.
Maybe it's the fact that it has 32MB of flash to work with, and only 128MB of ram. But that should be enough to run Solaris.
--Joe
2009/08/27
FSF Windows 7 sins
I don't normally post political messages here, but this one's important, I think.
The Free Software Foundation has posted 7 Windows 7 "sins" at http://windows7sins.org/, and I think they left out what in my mind is the most important issue. It's sorta covered in "Corrupting Education" and "Lock-In", but not really:
With Windows 7 (and Office 2003 before that, and Vista before that, and XP before that, and Windows 9x/W2K before that) users will have to retire/obsolete all of their existing training in the Windows user interface in favor of the newest cosmetic decisions Microsoft has made for its products.
I don't argue that there aren't significant productivity benefits to the current Windows shell (vs. Program Manager in NT and 3.x) or in the improvements from '95 to XP. I haven't seen much of Vista's Aero, or the new Windows 7 UI, and I'm sure all of the changes have been run by major interface testers.
But when I switched from Office 2000 to Office 2003, I had a rather steep learning curve to deal with the "Ribbon" UI. Even though I taught Office 97 to Computers 101 users in grad school (and was able to take that through to O2K) I was lost with the new "Where the h*** did the menu go" interface. (Ok, If I were an Excel developer, would I consider search&replace General (Home) thing, or a Data thing. It used to be in the Edit menu... )
But I relearned. And I was able to relearn because as I was growing up, the UI changed dramatically (from Write on my Apple ][+ to PC/Word Perfect to WPfW to vim/TeX and on to MS Office*) But for someone who's used to and has memorized the keystrokes/mouse clicks to insert a text box, this is a whole new ballgame.
When I was applying for jobs after college for example, one of the companies asked that I take an "aptitude test" which included things like typing speed and accuracy, formatting documents, generating mail merges etc. This computer-based test was graded on if you click the right menu option first. If you picked "Edit" instead of "Tools" (or if you right-clicked and chose "Format") you got the question wrong. Not that this was a good test, but it's typical for the industry. And the answers completely changed when 2K7 came out.
Of course, in my line of work, we're more concerned about the OS than about the Office apps. So it's things like the changes in networking that annoy me about Vista. Wow, the way I set up a dialup connection has changed. Hmm, I wonder what happens if I right-click here... etc. So I have to learn a whole new way to fix things that go wrong. Not to mention that Vista Home is quite different interface-wise than Vista Business.
And I'd expect that the various Windows 7 editions will look different too. After all, would the wizard that helps gramma connect to the wireless internet at Starbucks be the best way for IT professionals to diagnose an 802.1x authentication problem? If I learn how to do it with my home PC, will that apply to the real business world?
--Joe
The Free Software Foundation has posted 7 Windows 7 "sins" at http://windows7sins.org/, and I think they left out what in my mind is the most important issue. It's sorta covered in "Corrupting Education" and "Lock-In", but not really:
With Windows 7 (and Office 2003 before that, and Vista before that, and XP before that, and Windows 9x/W2K before that) users will have to retire/obsolete all of their existing training in the Windows user interface in favor of the newest cosmetic decisions Microsoft has made for its products.
I don't argue that there aren't significant productivity benefits to the current Windows shell (vs. Program Manager in NT and 3.x) or in the improvements from '95 to XP. I haven't seen much of Vista's Aero, or the new Windows 7 UI, and I'm sure all of the changes have been run by major interface testers.
But when I switched from Office 2000 to Office 2003, I had a rather steep learning curve to deal with the "Ribbon" UI. Even though I taught Office 97 to Computers 101 users in grad school (and was able to take that through to O2K) I was lost with the new "Where the h*** did the menu go" interface. (Ok, If I were an Excel developer, would I consider search&replace General (Home) thing, or a Data thing. It used to be in the Edit menu... )
But I relearned. And I was able to relearn because as I was growing up, the UI changed dramatically (from Write on my Apple ][+ to PC/Word Perfect to WPfW to vim/TeX and on to MS Office*) But for someone who's used to and has memorized the keystrokes/mouse clicks to insert a text box, this is a whole new ballgame.
When I was applying for jobs after college for example, one of the companies asked that I take an "aptitude test" which included things like typing speed and accuracy, formatting documents, generating mail merges etc. This computer-based test was graded on if you click the right menu option first. If you picked "Edit" instead of "Tools" (or if you right-clicked and chose "Format") you got the question wrong. Not that this was a good test, but it's typical for the industry. And the answers completely changed when 2K7 came out.
Of course, in my line of work, we're more concerned about the OS than about the Office apps. So it's things like the changes in networking that annoy me about Vista. Wow, the way I set up a dialup connection has changed. Hmm, I wonder what happens if I right-click here... etc. So I have to learn a whole new way to fix things that go wrong. Not to mention that Vista Home is quite different interface-wise than Vista Business.
And I'd expect that the various Windows 7 editions will look different too. After all, would the wizard that helps gramma connect to the wireless internet at Starbucks be the best way for IT professionals to diagnose an 802.1x authentication problem? If I learn how to do it with my home PC, will that apply to the real business world?
--Joe
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