Tag Archives | DLSLUG

DLSLUG notes, 5-Apr-2007: Todd Underwood discusses ZFS

Fifteen attendees made it to the April meeting of the Dartmouth Lake
Sunapee Linux User Group
, held as usual in Carson Hall at the Dartmouth College campus on the first Thursday of the month.

Todd Underwood, Vice President, Operations and Professional Services at Renesys presented “ZFS: The Last Word in File Systems.” Renesys is in the business of collecting, analyzing and archiving data about what’s happening on the internet and, not surprisingly, that’s a lot of data and growing geometrically. One of Todd’s projects is to provide fast and reliable storage for the hundreds of gigabytes per day acquired and the tens of terabytes of data stored. He presented a survey of what’s out there, what his needs were, and how he reluctantly narrowed the search down to SUN Solaris and ZFS. While he had nothing but praise for ZFS, he expressed some reservations about SUN. Strong reservations.

Todd dug into the ZFS architecture. ZFS is truly amazing: disk contents are always coherent, with writes all checksummed, writes as atomic transactions, with “fancy FS internals” like IO scheduling, dynamic block sizes and prefetch queues, huge limits (128-bit data). ZFS flattens the Linux file system model of multiple layers into a single monolith, and eliminates entire classes of problems introduced by the multiple layer architecture. There is no fsck. Devices are accumulated into pools. File systems are assigned to pools. Storage addition and maintenance is fairly trivial. ZFS performance is remarkable, at disk speed (with compression, sometimes in excess of disk speed).

Todd presented the rough outlines of his storage system: $17k worth of hardware from SUN and Dell yields 7.5 terabytes of storage with nearly a gigabyte per second throughput. Todd’s disk storage challenge is solved, as the company’s demand can’t match the throughput capacity of his system, for now, and the system can be expanded with additional external storage.

As for the porting of ZFS onto other architectures, Todd expressed the opinion that running on Solaris or OpenSolaris is likely the best current solutions. Porting onto BSD is underway but not yet ready. He had heard that ZFS was ported to OS X but could not confirm (Googling ZFS OSX yields interesting results).

Todd promises to send along slides from his presentation; I’ll try to post links to them to the website.

After the main presentation, there was a good session of questions and answers. I asked a question on replication of Postgres and Todd recommended the Sequoia product.

Thanks to Todd for his thorough presentation, to Bill McGonigle for organizing the meeting, to Bill Sconce for sharing his notes with me for this post, and to all for attending and participating. Next meeting, still tentative, will be on writing a FireFox extension by Roger Trussell.

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DLSLUG: April 5th: Todd Underwood: ZFS

Bill McGonigle announces the April meeting of the Dartmouth – Lake Sunapee Linux User Group. The main presentation will be “ZFS: The Last Word in Filesystems, ” presented by Todd Underwood, VP of Operations and Professional Services, Renesys Corporation. Here’s the pitch:

ZFS is the most original work in storage management in years. It offers a revolutionary, integrated approach to block device, raid, volume management and filesystem technology. We’ll take a high-level look at what makes ZFS so different from previous storage technologies and look at efforts to port ZFS to free operating systems (ZFS is available for FreeBSD and in a userland port to Linux, but the path will not be easy).

Todd has with more than 10 years experience in architecting, building, and supporting large-scale distributed systems. Before Renesys, Todd was senior vice president and chief technology officer at Oso Grande Technologies, the largest Internet service provider in New Mexico, where he was the lead consultant in the security practice. Before that, Todd was chief technology officer at Lightdart Managed Data Centers, a co-location and hosting start-up built in partnership with Public Service Company of New Mexico. As a graduate student, Todd led the effort studying high-speed networking for large-scale computer clusters at the University of New Mexico. Todd holds a B.A. from Columbia College, Columbia University and an M.S. in computer science from the University of New Mexico.

Looking forward to the meeting. Hope to see you there!

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PySIG, 22-March-2007: Project Night

An even dozen people showed up for the Python Special Interest Groups March meeting, held as usual at the Amoskeag Business Incubator in Manchester, NH.

Bill Sconce called us to order promptly at 7 PM and we proceeded through the printed agenda. It was duly noted the Ben Scott deserved heckling despite his absence. We ran through announcements of a couple of upcoming meetings, plugging the MythTV installfest beta and pointing out Jarod’s book. We mentioned meetings upcoming for the LUGs, including ZFS at DLSLUG, LVM at CentraLUG and the new Ruby group.

Kent’s Korner: Kent S. Johnson presented his month talk, this month on list comprehensions. Kent had a great handout, and has collected his past couple of handouts in one place. Starting with simple examples and building in complexity, Kent lead us through what can be an intimidating topic in a way most couple follow. Some great discussions, on-topic and off-, regarding assignment and Python idioms, always make this a fun part of the meeting.

There was some discussion of Python 3000 and its expected schedule. Bill Sconce had a video of Guido practicing his Py3K presentation in front of an audience at Google, which he went on to present at PyCon.

For the Gotcha of the month, Bill Freeman offered up an “Un-Gotcha:” a=b=4 works, but not for the reason you might think. Assignments of this style in C have a different underlying meaning, and perhaps in some circumstances, different side effects. A key to understanding the single = assignment in Python is to understand that it is a STATEMENT. There is no value associated with the statement and “chained” assignments in Python like the above are specially-coded as an exception case. This lead to yet another great discussion.

Ric Werme showed off the web pages that result from his Python software that collects and forwards weather data from his weather station. His current conditions page, http://home.comcast.net/~ewerme/wx/current.html has links to everything else. Ric bought the weather station in part to have an excuse to write more Python code, and his current code runs the gamut from implementing the weather station protocol through pyserial.py and the serial port to CGI scripts that take data requests, fetches the data from MySQL, creates gnuplot data files that create .gif files, and returns a HTML page to display the results. His description of the software is at http://werme.8m.net/wx/vantage_software.html .

Ric also demonstrated a Python cgi script for collecting data for a weather observers group that Todd Gross created while he was WHDH. It’s customizable, so people can create a form preloaded with their location that offer just the data they collect, and the submission code adds it to a MySQL database and recreates a web page of members reports over the previous day.

Shawn O’Shea showed off Python running in the Win32 and COM environments. Shawn does a lot of work administering and automating Windows configurations, and the COM set of interfaces can allow a lot of internal manipulation of the major applications, a big step up from the VBScripts supplied by Microsoft with some of the tools. Shawn demonstrated the canonical Hello, World with Microsoft Word, but then dug into a couple more concrete and practical examples with querying the Registry and spelunking in the IIS metabase.

Lots of interesting stuff coming up at future meetings: Martin Ledoux offered to show something on the work he’s done with amateur book-binding with pytut/pyref books. Kent has promised an update soon on his real-life experiences with Django. Ray Côté may be able to show off the new web site he used as an excuse to miss the meeting. And I’ll bet Bill will wheedle some more cookies from Janet.

Thanks to Bill Sconce for organizing, Alex Hewitt for getting the networking working, the Amoskeag Business Incubator for providing the great facilities, Janet for the awesome cookies, Kent for his great Korner, Bill Freeman for the csv module and those strange blinking white blocks, Ric Werme for demoing his weather projects, Shawn for the Win32-COM-Automation and everyone for attending and participating.

P.S. Anyone got python running on a WRT54G?

P.P.S. Tom Mosco mentioned to me that the Chicago Python group had a very long presentation on Django by the creators and also a Ruby on Rails presentation by its author. Videos can be found at here and here

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DLSLUG 1-March-2007: Bill Stearns on “50 Ways to Run Your Programs”

Fourteen attendees managed to find the monthly meeting of the Dartmouth – Lake Sunapee Linux User Group, despite being held one floor up from the regular meeting room. (A reminder from yours truly that you can save yourself a trip down and up the stairs if you just Read The Fine Announcement Bill McGonigle prepares each month. I needed the exercise anyway.)

Bill Stearns presented “50 Ways to Run Your Programs,” He had tremendous handouts: a vinyl 3-ring notebook binder with 61 pages. He asked us all to skim the materials and pick out the couple of techniques we wanted to drill down into. He covered in some depth (though each could get its own book): passing commands through ssh, combining screen with ssh, using wget as part of a pipe, how wget can work with caching, using tee to redirect output through the pipe as well as to a file simultaneously, the precedence of && in sequencing commands on the command line, some of the implications of subshells and environment variables, gotchas with cron, using eval and netcat. Bill is knowledgeable and rolled well with the punches, like his new HP widescreen battleship of a laptop refusing to run X on the projector. (Bill had an aside about the joys of Open Source providing the means of fixing some bad interrupt logic in the BIOs with a kernel switch – yay, Open Source!) Bill hardly broke a sweat despite the attendance of Professor McIlroy, who is credited with having invented the pipes and filters architecture of Unix. A good time was had by all, with lots of time for questions (from novices “What does that do?” to some pretty advanced questions on piping and subshells and so forth.)

Next meeting is 5 April when Todd Underwood will present ZFS. Thanks to Bill McGonigle for organizing the meeting, Bill Stearns for the great presentation, and all for participating.

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DLSLUG, March 1st 2007: 50 Ways to Run Your Programs

Bill McGonigle announces the March meeting of the Dartmouth-Lake Sunapee Linux User Group, featuring “50 Ways to Run Your Programs” presented by Bill Stearns. Sounds like a great meeting!

“At this meeting Bill will explore ways to change how programs run. He will cover ways to change a program’s priority, where it runs, when it runs, debug new and running applications, and much more. Attendees are welcome, and encouraged, to bring their own laptops and try new techniques that will help them tap the power of a Linux environment.”

“William Stearns is a network security researcher and instructor for the SANS Institute, teaching the Linux System Administration and Perimeter Security tracks. In his spare time he maintains a major antispam blacklist and assists the technical community as a volunteer incident handler for the Internet Storm Center. His articles and tools can be found in SysAdmin magazine, online journals, and at http://www.stearns.org.”

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MonadLUG notes: 8-Feb-2007: uniq and Joomla!

Charlie Farinella called the meeting to order promptly at 7 PM and cracked his whip to stick to his streamlined agenda. Brief announcements (“find GNHLUG events on www.gnhlug.org”) were followed by Ray Côté’s presentation of uniq. Ray explained the function and then introduced an increasingly complex set of examples, one building on another to show how uniq could remove duplicate lines from a sorted file, display various counts of duplicates and so forth.

Guy Pardoe was the main presenter. After the requisite wrestling with the projector, Guy talked about Joomla! Guy had hoped to be showing version 1.5, but it is still in early beta (beta 1 with beta 2 due rsn), so he didn’t feel it was ready to talk about for production sites. Guy explained when he volunteered for the presentation he thought 1.5 would be available, and promised to return when 1.5 was available and he had some experience in using it for production work. He briefly reviewed Barrie North’s presentation from DLSLUG last year (registration required) (and our notes from that meeting). Guy then showed us the Joomla! 1.0 correction: 1.5 install he had done that day, highlighting the basic features of the CMS and the ease of use of the administrative interface. It appeared to be a very open and accessible system. Templates and CSS files could be edited from within the interface and they appeared to be XHTML and CSS2 compliant.

A general Q&A followed. General concerns on the security of the core framework. Concern about the timeliness of the 1.5 release. General discussion of what CMS could do and what the target market was.

After the main presentation, the floor was opened up for general discussion. Maddog announced that he and Bill Sconce had met with faculty at the New Hampshire Technical Institute and that a plan to hold a series of MythTV Installfests was proposed (see the -org list for details).

Answering another question that has come up on the discusssion list, I came across this post while I was looking for Barrie’s presentation. While he is advocating for Joomla!, of course, he may be pointing out that WordPress would meet some peoples needs as well.

Why you want to use Joomla! instead of WordPress

Thirteen attendees were at the meeting. Thanks to Charlie for running the meeting, Ray and Guy for presenting, Ken and the Monadnock SAU for providing the facilities, and to maddog and all attendees for participating!

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Notes from CentraLUG meeting, 5-Feb-2007: Matt Brodeur and GNUPrivacyGuard

We were lucky last night to have Matt Brodeur drive up from his day job at RedHat in Westford, MA to present a meeting on GPG, the open source implementation of OpenPGP, the Pretty Good Privacy algorithms and utilities. Matt had a slideshow in OpenOffice.org 2 Impress (available at http://www.nexttime.com/mbrodeur/GPG2007) and in PDF here.

Eleven attendees made it to the meeting. Matt briefly discussed the origins of PGP, and then dove right into the process and utilities of how Privacy Guard works. Matt also had brought some scripts he replayed to walk through the sequence of generating a key pair, signing another’s key, sharing keys to a keyserver. Matt walked us through the concepts behind the Web of Trust and the issues and processes of revoking keys. During the presentation and following, there were a fair number of questions and Matt dealt with them well.

Although we had hoped to have a keysigning as part of the meeting, we elected to postpone that portion to future meetings. As the group is fairly small, we agreed we can do individual signings as needed.

Future meetings: March 5th will feature Andy Bair talking about “Digital Forensics File Carving,” a popular topic he’s presented at several other groups. On April 2nd, William Stearns will do a presentation on Logical Volume Management. I saw Bill do an LVM presentation at DLSLUG back in 2005, and he had a great presentation. Looking forward to seeing both presentations!

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DLSLUG, 2 Nov-2006: FOSS in Schools

Bill McGonigle announces the November 2nd meeting of the Dartmouth-lake Sunapee Linux User Group meeting, at a different location than usual:

The next regular monthly meeting of the DLSLUG will be held Thursday, November 2nd, 7-9PM at Dartmouth College, Silsby Hall, Room 312. All are welcome, free of charge.

“Open Source in Schools” presented by Dave Clifton

Dave will be talking about the use of Free / Open Source Software in schools and will chronicle the growth of the infrastructure at the Plainfield Elementary School (NH SAU 32) since 2002. There will be an emphasis on choosing appropriate software, the real costs of going down the F/OSS path, and some potentially surprising stories about what the Plainfield School is doing today.

Dave is currently a Senior Systems Administrator for
Ansys (formerly Fluent) in Lebanon, NH. He holds a Master's degree in Applied Mathematics from Johns Hopkins and spent ten years doing consulting work for various government agencies and Bell Atlantic before escaping from DC to the Upper Valley in 1998. He got his start as a sysadmin in the mid-1980s running Masscomp Real-Time Unix and SunOS 4.0.3 and has subsequently worked on more operating systems than he wants to remember.

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DLSLUG, October 5th, 7 PM: Protecting a Windows Server with a $50 Linux Box from Staples

Bill McGonigle announces Thursday's Dartmouth-Lake Sunapee Linux User Group: “Protecting a Windows Server with a $50 Linux Box from Staples” presented by Lloyd Kvam:

“Lloyd will talk about OpenWRT, the open source linux distribution that targets small routers such as the Linksys WRT45GL. He recently used one to make a bridging firewall, where a Windows computer needed protection, but there was no access to the router.”

“Lloyd will talk about hardware organization, installing packages, the layout of the default configuration, and how to customize the routing and firewall operations… Lloyd works at software development, preferably in Python.”

Should be a fun meeting. Hope to see you there!

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